UDOT Construction Inspection Guide CHAPTER 4: Drainage
Published November 2012
Table of Contents Drainage 4.3 Drainage Structures
02633 – Concrete Drainage Structures
4.1 Pipe Culverts - Introduction
Well designed and constructed drainage systems are a critical component of …..
02610 – Pipe, Pipe-Arch, Structural Plate Pipe and Structural Pipe Arch
This section covers the inspection of the materials and procedures used for installing….
02613 – Culvert End Sections
The contractor should use culvert end sections made of the same materials as the pipe…
This section includes the inspection of catch basins, drop inlets, inlets, and manholes….
02635 – Grates, Solid Covers, Frames & Manhole Steps Inspection Checklist…
02643 – Concrete Lined Ditch
Inspecting concrete lined ditches requires an understanding of pervious chapters, particularly….
02611– Diversion Box Gate and Frame
Inspectors must ensure the contractor has properly installed and used the correct materials….
02624 – Approach Slab Catch Basin
This section covers the inspection of the construction of a drainage catch basin in the approach slab ….
02625 – Approach Slab Drain Frame Modification This section covers the inspection of providing a frame riser to raise the existing drain grate ….
02626 – Deck Drain Modification or Closure
The contractor must modify or close existing drains and install new drains at locations specified….
4.2 Box Culverts
02646 Concrete Box Culverts Culverts channel water under roads, railways and embankments. When inspecting…. 02645 Precast Concrete Box & 3 Sided Culvert Structures Precast unit inspection requires materials approval and installation inspection….
02622 – Underdrain
This section covers inspection procedures for placing pipe underdrains. Inspectors should be familiar….
4.4 Rip Rap
02372 – Wire Enclosed Riprap
This section covers the inspection and procedures for wire enclosed riprap which is constructed by ….
02373 - Riprap
This section covers the inspection and procedures for loose riprap, hand placed riprap and plated…
02374 – Grouted Riprap
This section covers the material requirements and procedures for grouted riprap …..
02376- Erosion Control Blankets/Channel Liners
This section covers the inspection procedures for erosion control blankets and fabrics. These materials.. ….
CHAPTER 4: DRAINAGE
4.0 INTRODUCTION
Chapter 4
Well designed and constructed drainage systems are a critical component of ensuring the longevity of a highway. Roadway drainage involves collecting surface runoff and other water sources to convey water to designated areas, ensuring traffic safety and protecting the roadway itself from damage. Water quality is an increasingly important concern, as roadway runoff contributes to non-point source pollution, so inspectors must adhere to applicable environmental controls. Many sections in this chapter closely follow a corresponding section in the Standard Specifications. However, the intent of this chapter is not to repeat the specifications, but to offer guidelines for inspectors to ensure compliance and to measure work done. All section numbers refer to the Standard Specifi cati ons 2012 edition. As explained in Chapter 1, the first duty of an inspector is to become thoroughly familiar with the contact plans, standard plans, special provisions, standard specifications, and any right-ofway agreements that apply to the particular project. This guide is not a substitute for a good understanding of the project plans and standard specifications. The sections of this chapter are further divided into the following subparts for most sections: • General briefly familiarizes the inspector with the section and describes the work covered in the section. • Before and During Construction describes tasks the inspector should perform during those phases of construction. • Submittal Requirements ensures the inspector gathers all necessary documentation during each phase of work for submission to the Office Manager or Project Engineer. • Site Inspection details specific items to look for during construction. • Common Issues Encountered familiarizes the inspector with common contractor mistakes.
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• Inspection Checklist describes the actions the contractor must take before construction begins and actions the inspector must take during the course of work. This checklist also includes the measurements and payments the inspector must complete. This provides the guidelines for measuring and paying for the work covered in the particular section.
4.1 PIPE CULVERTS – GENERAL INFORMATION The life of a roadway depends largely upon well-designed and constructed drainage systems. Pipe culverts are a key component of these systems and correct placement is critical for proper function. The inspector must therefore understand staking information and be able to check for correct placement and installation of culverts and the other drainage features utilized on the project. It is necessary to inspect the drainage facilities to ensure proper sizing and quality of construction. For additional information refer to Appendix C.
A) PIPE, PIPE-ARCH, STRUCTURAL PLATE PIPE, ARCH – SECTION 02610
AND
STRUCTURAL PIPE
General This section covers the inspection of the materials and procedures used for installing pipe. Inspectors should be familiar with the class, type, size, and thickness designations of pipe called for in the plans, as well as any asphalt coatings to be used. Pipe and pipe arch are identified according to diameter or by span and rise and according to corrosion classification. Refer to Section 02610 for definitions of materials and procedures used. Keep in mind the Utah Occupation Safety and Health Regulations that apply during this phase of construction.
Before Work Begins The inspector should request copies of the contractor’s submitt als to the Department for approval. Refer to Section 02610 and the Minimum Sampling and Testing Guide (MS&TR) for detailed guidance on materials certi fication. The Page | 2
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CHAPTER 4 contractor may perform the acceptance testing, or use the services of a UDOT approved third party testing company. The Department must not accept any damaged pipe, so inspectors should ensure that damaged pipe is never used. Pipes are accepted after verification that the materials meet the specification’s requirements. These elements include horizontal and vertical alignment deviations, barrel distortion, any damage to the pipe, joints, and coating integrity. Refer to Secti on 2.1 of 02610 for types of pipe and the DG Series Standard Drawings for pipe type selection.
During Construction Proper placement of the pipe is critical to the drainage system operating correctly. The inspector must understand the information on the offset survey stakes and check for proper placement of drainage items. Be sure the system will drain the intended area. As excavation progresses, check line and grade. Refer to Chapter 3 of this guide, Section 02317, and the DG Series Standard Drawings. Refer to Section 1.6 of 02610 for acceptance criteria once pipe has been placed. Inspection of the cross culverts, storm drains, and irrigation pipes installation must be done prior to placing the roadway pavement. The Engineer should have selected 25% to be inspected in addition to any areas with defects. The Department will pay the cost of any requested additional tests that show the pipe tested being in compliance with the criteria in Section 02610. The contractor should furnish pipes with joints that can sustain minimum pressures. Each pipe type must be tested according to the proper AASHTO and ASTM test requirements by an independent lab or witnessed by a UDOT representative. The contractor must comply with the manufacturer’s recommendations for connecting pipes and for connecting pipes to concrete headwalls, catch basins, and similar structures.
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Verify bedding material and placement is accepted in accordance with Section 02056 and the requirements shown in the Standard Drawings DG 5a, 5b and 5c. Placed bedding material should be smooth, free of protruding rocks and conform to the surveyed grade. If excavation violates OSHA safety standards by not using a trench box or shoring, notify the contractor and report the condition to the Senior Inspector or the Resident Engineer. Refer to the standard drawing DG 5. The material should be properly moistened and compacted to the required density by means of a mechanical tamping device approved by the Resident Engineer. When the top of the pipe is exposed above the top of the trench, embankment material, the same material used for trench backfill, should be placed and compacted by mechanical tamping. The remainder of the adjacent side fill may be regular
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CHAPTER 4 embankment material and can be compacted with power equipment as long as is can be done with no damage to the pipe. The adjacent side fill shall be placed and compacted to a minimum width of two diameters of the pipe or 12’, whichever is less, prior to use by traffic or construction equipment. All materials should be installed according to manufacturers’ instructions to conform to AASHTO Standard Specifications for Highway Bridges. The joints should be closed in accordance with the manufacturer’s recommendations.
Sampling and Testing The unit sampled depends on the type of pipe being inspected. Inspect the entire length of cross culverts and the entire length of pipe between manholes or other junction structures when inspecting closed conduits, such as storm-drains and irrigation pipes. Visually inspect all other pipes as needed and be sure to follow OSHA requirements when performing inspections in confined spaces. Use a mobile video camera to inspect and record the condition inside of installed pipes. Manual measurements of pipe deformations will always need to be completed and verified with the Engineer to ensure requirements have been met. In some cases of pipe de- formation, the Engineer could require a Mandrel Test to verify that the installed pipes meet specification requirements. All pipes that fail the Mandrel Test and that do not exceed 10% deflections, the contractor must provide engineering analysis certifying the structural and hydraulic integrity of the pipe to the Resident Engineer and Central Hydraulics, signed and sealed by a professional engineer licensed in the State of Utah, for pipe acceptance to take place. The inspector should request a copy of this submittal. If engineering analysis does not take place, inspectors must apply the pay reduction schedule to sample units left in place that have pipes that do not meet Mandrel Test requirements. The contractor must remove and replace all pipes that exceed 10% deflections. This pay reduction schedule is outlined in the table below.
PIPE DEFLECTION PAYMENT REDUCTIONS
Amount of Deflection (%)
Payment
0.0 to 5
100% of the Unit Bid Price
5.1 to 9.9
75% of the Unit Bid Price
10 or greater
Remove and Replace
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In addition to the inspection requirements in Section 02610, Article 1.6 paragraph C, test the joints of all storm drains and irrigation pipes with diameters equal to or less than 42” when visual inspection indicates noncompliance with the criteria. Test all pipes that have joints showing visible gaps, defects, or any other problem with an air or exfiltration testing method. The contractor must repair all areas of damage that do not pass tests at no cost to the Department. See Section 02610 for leakage allowances. Repaired areas must be retested and replaced until these areas pass leakage tests. The table below will assist in the inspection process. PIPE TESTING REQUIREMENTS ACCORDING TO PIPE FUNCTION OF CRITERIA IN SECTION
Pipe Category & Size
Visual: Sight
Cross Culverts ≤ 48” Diameter Cross Culverts > 48” Diameter
X* X
Storm Drains/Irrigation Pipes ≤ 48” Diameter Storm Drains/Irrigation Pipes > 48” Diameter
Physical: Leakage: Video Recording Manual Measure
Airor Water Test
When visual test shows non-compliance
X X*
X
X*
Mandrel (See Article 1.6.C6)
X*
When visual test When visual test shows non-compliance shows non-compliance
X
When visual test shows non-compliance
* Both methods are acceptable for pipes with diameters larger than 30”.
Before applying any coatings, the contractor should remove moisture, dirt, oil, un-bonded or incompatible paint, grease residual oil, alkalis, or other foreign matter from the surface to be coated. To conduct verification tests of the coatings, the Department will take a representative sample from each lot furnished by the contractor. The contractor should repair or replace any damaged materials. Asphalt coatings are not allowed on structural plat pipe and plate pipe arch. Generally, the inspector should ensure the contractor has provided adequate cover or protection for all pipe during project construction. The contractor must replace all damaged pipe before acceptance by the Department. Some causes for rejection are irregular or distorted shape, dents, bends, damaged, broken, delaminated, scaled coatings, loose bolts or nuts, uneven laps, improper fitting joints, or any damage that compromises the functionality and design life of the pipe. Page | 6
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CHAPTER 4 Inspectors should document equipment and manpower utilized, as well as damage, re- pairs, density tests, pay quantities, and pay adjustments.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Utility Location and Protection (Blue Stakes receipt form) 2. Documentation of Density Testing 3. Documentation of Lift Thickness 4. Documentation of Random Sample and Test Location or Interval 5. Material Approval and Inspection 6. Acceptance Criteria Documentation
Site Inspection Inspect the site for proper construction: 1. Trenching & Excavation meets OSHA Guidelings 2. Material is properly placed 3. Material is certified per UDOT standards 4. Material was tested and reports received approval
Common Issues Encountered Document these common contractor mistakes: 1. Existing Drainage feature is not maintained 2. Site isn’t properly prepared before installation 3. Pipe inspection is not performed and accepted prior to placement of Pavement 4. Damage occurs and isn’t repaired 5. Quantities are incorrectly measured
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02610: PIPE, PIPE-ARCH, STRUCTURAL PLATE PIPE, AND STRUCTURAL PIPE ARCH
Pre-Inspection Items Contractor has located and protected utilities within the affected area by contacting Blue Stakes before disturbance. Refer to Sections 00820 and 01571. Inspector has cross referenced the plan summary sheets. Site preparation, including pre-compaction, is complete. Correct pipe was used according to the plan specifications, including material, size and class. All manufactured materials are certified as per UDOT standards. Contractor has provided the manufacturer’s Certificate of Compliance (COC) or product data indicating the materials furnished meets specification requirements. Contractor has provided the manufacturer’s Certificate of Compliance (COC) certifying the coating thickness and that the pipe joints meet or exceed the specified pressure requirement for the application. Contractor has completed all required UDOT Test Reports.
Field Documentation Items Visually inspect materials and site before placement to ensure; pipe fits drainage, tight joints, horizontal and vertical alignment for bellies or bends, camber if required, proper coating, and bolt tightness. Inspector then completed Form 150, Culvert Inspection. Verify proper slope, invert and outlet elevations, proper flow direction, and inlet and outlet survey. Visual inspection for damage to pipe structure including dents, holes, abrasions, or cracks. Bedding, backfill, and compaction requirements have been met, specified depth and lift thickness, test reports and testing frequency per MS&TR. Ensure excavation and bedding are executed properly and according to standards. Ensure bedding and backfill are compacted to 96% maximum laboratory density and placed in 6” lifts. Document all activities in daily diary or electronic field book. Inspector has witnessed contractor’s testing per acceptance criteria specified in Section 02610. Video or visual inspections have been performed. Ensure pipe and other components are placed in correct locations. Check placement locations against survey stake information and document results. Mandrel pressure testing if necessary. Document equipment and manpower utilized. Document density results with random locations. Determine pay quantities by measuring and documenting the length of pipe placed and placed quantity of related items. Payment adjustments for pipe deflections have been made. Ensure conditions of Section 1.6 of 02610 are met and documented as required.
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B) CULVERT END SECTIONS – SECTION 02613 General The contractor should use culvert end sections made of the same materials as the pipe or pipe arch to which they are connected. The only exception would be when the contractor should use a metal end section with HDPE with concrete pipe according to AASHTO M294. The coating applied to the metal end section should be identical to the coating applied to the pipe material. The end section should be placed according to the construction methods specified for the type and class of pipe to which they connect. Refer to DG Series Standard Drawings and Section 02610 for more information.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Material Certification
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards 3. Compaction is correct
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Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Missing Hardware 3. Damage occurs and isn’t repaired 02613: CULVERT END SECTIONS
Pre-Inspection Items Utilities have been located and protected. Inspector has cross referenced the plan summary sheets.
Field Documentation Items The contractor has used the correct size, type, material, coating or finishing. There is a tight connection to pipe, and no damage to the pipe. Grading allows proper drainage. Backfill and compaction are correct.
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4.2 BOX CULVERTS
A) CONCRETE BOX CULVERTS – SECTION 02646 General Culverts channel water under roads, railways and embankments. When inspecting concrete box culverts, inspectors should ensure the contractor has provided waterstops as shown in the plans, and adhered to all other requirements as specified in the plans and standard specifications. Contractors should notify the Department in writing at or before the preconstruction conference about which concrete box culvert type will be used at each location. Substitutions may be made. For example, precast reinforced concrete box culverts may be substituted for cast-in-place reinforced concrete box culverts as shown in the plans unless specified otherwise in the contract. This substitution requires contractors to meet all requirements and submittals of Section 02645, Precast Concrete Box and Three-Sided Culvert Structures, detailed in the following section of this chapter. Concrete box culverts may be accepted at a reduced price when the concrete strength is below that specified. Reference Section 03310 for price adjustments. If cast-in-place culverts are used, inspectors should ensure that contractors do not backfill until the concrete has been in place at least 7 days and has attained the specified strength.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Signed and Sealed Drawings and Calculations 2. Prequalified Source Documentation 3. Backfill Documentation
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
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Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Damage occurs and isn’t repaired 3. Material is installed incorrectly 02646: CONCRETE BOX CULVERTS
Pre-Inspection Items Shop drawings and design calculations signed and sealed by Utah licensed professional engineer. Contractor has used a prequalified source for precast structures.
Field Inspection Items Site is excavated to the required depth and elevation. Contractor has used suitable materials for backfill, depth of lift, optimum moisture and compaction. Refer to Chapter 3 of this guide. Contractor has provided the test reports from the UDOT Materials Division for precast structures. Compaction and fill requirements have been met. Backfill documentation per MS&TR Section 02056.
B) PRECAST CONCRETE BOX SECTION 02645
AND
THREE-SIDED CULVERT STRUCTURES –
General Precast unit inspection requires materials approval and installation inspection. The contractor must furnish to the Engineer all shop drawings and design calculations, and keep in mind that the Department will reject any units fabricated before written approval of the fabricator’s shop drawings was received. Ensure any precast units are stamped with the date of casting and supplier identification. The contractor must replace any cracked or damaged units at no additional cost to the Department.
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During site inspection, ensure the area is properly excavated, trenched and backfilled, and that minimum bedding requirements have been met. The contractor must over-excavate as directed by the Engineer.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Signed and Sealed Drawings and Calculations 2. Prequalified Source Documentation 3. Test Reports for Precast Structures Submitted 4. Backfill Documentation
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved 3. Damaged units are not replaced 02645: PRECAST CONCRETE BOX AND THREE-SIDED CULVERT STRUCTURES
Pre-Inspection Items Inspector has cross referenced the plan summary sheets. Shop drawings and design calculations are signed and sealed by Utah licensed professional engineer. Contractor has provided the test reports from the UDOT Materials Division for precast structures. Contractor has used a prequalified source for precast structures.
Field Inspection Items Contractor has excavated the site to the required depth and elevation. Contractor has used suitable materials for backfill, depth of lift, optimum moisture and compaction. Refer to Chapter 3 of this manual. Backfill documentation per MS&TR Section 02056.
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4.3 DRAINAGE STRUCTURES
A) CONCRETE DRAINAGE STRUCTURES – SECTION 02633 General This section includes the inspection of catch basins, drop inlets, inlets, and manholes. Contractors must construct cast-in-place or install precast drainage structures to meet all requirements of the Section. The Engineer must be notified in writing on the selection of the method of construction, and the contractor may not change construction methods thereafter without written approval from the Engineer.
During Construction All pre-cast structures furnished must be in conformance with the CB Series Standard Drawings and the contractor should provide verification of UDOT prequalification for precast supplier, when applicable. All cast-in-place structures must have an approved mix design. Additionally, ensure contractors have repaired or replaced any structures that have fractures, cracks, damage, honeycombing, or defects and submitted repair procedure to the Engineer for approval. Ensure the contractor has performed either the vacuum test or ex-filtration test to verify the drainage structures are watertight. The contractor must receive acceptance from the Engineer after installation and before backfilling.
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Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Concrete Mix Design Approval 2. Signed and Sealed Drawings and Calculations 3. Certificate of Compliance 4. Prequalified Source Documentation 5. Backfill Documentation
Site Inspection Inspect the site for proper construction and document the contractor’s actions: 1. Excavation meets OSHA requirements 2. Field verify the fit and function at structure location before construction or manufacturing. 3. Installed materials are at specified elevations 4. Material is certified per UDOT standards 5. Verify the connection of the pipe and drainage structure is properly sealed as per section 02633 3.1C 6. Installation was inspected and accepted before backfilling began 7. Verify reinforcing steel sizes, epoxy coating, and spacing
Common Issues Encountered Document these common contractor mistakes: 1. Field verification of exisiting features where not verified. 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved 3. Damage is not repaired
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CHAPTER 4 02633: CONCRETE DRAINAGE STRUCTURES
Pre-Inspection Items Utilities have been located and protected. Inspector has cross referenced the plan summary sheets. Contractor has used an approved mix design for cast-in-place structures. Inspector has verified reinforcing steel sizes, epoxy coating, and spacing for cast-in-place structures. Contractor has used a prequalified source for precast structures in accordance with UDOT Quality Management Plan. The inspector must verify type and structure I.D., and cross reference these to the plan summary sheets. Structures are marked with date of casting and supplier identification. Contractor has provided the manufacturer’s Certificate of Compliance (COC) for reinforcing steel. Contractor has provided manufacturer’s product data, specifications, and recommended installation instructions for curing compounds, if applicable. Contractor has verified the fit and function of the concrete drainage structure.
Field Inspection Items Engineer has approved installation before placing backfill. Contractor has used suitable materials for backfill, depth of lift, optimum moisture and compaction. Refer to 3.3. Compaction and fill requirements have been met. Backfill documentation per MS&TR Section 02056. Contractor has excavated to the required depth and installed materials at the required elevation. Contractor used coated reinforcing steel and non-shrink grout, if applicable.
B) FURNISH AND INSTALL GRATES, SOLID COVERS, FRAMES, MANHOLE STEPS – SECTION 02635
AND
02635: GRATES, SOLID COVERS, FRAMES & MANHOLE STEPS Contractor has used the correct type, foreign or domestic steel. Contractor has used the correct step spacing. Offset from curb or barrier is correct. Contractor has used proper placement methods, including orientation, and installed according to plan specifications.
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C) CONCRETE LINED DITCH – SECTION 02643 General Inspecting concrete lined ditches requires an understanding of previous Chapters, particularly embankment, borrow, backfill, and concrete sections. If the finished concrete strength is below that specified by the plans, the ditch may be accepted and paid at a reduced price. The inspector should follow the price adjustment pay factor in Section 03055.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Verified plan dimensions 2. Concrete Mix Design Approval 3. Concrete curing compound approval
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards 3. Concrete strength is tested
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Material is installed incorrectly 3. Required compaction is not achieved Page | 18
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CHAPTER 4 02643: CONCRETE LINED DITCH
Pre-Inspection Items Inspector verified plan dimensions and locations. Contractor has properly compacted the ditch before concrete application. Contractor has finished the ditch surface to remove projections and honeycomb. Concrete mix design was submitted and received approval from the Engineer.
Field Inspection Items Contractor has documented concrete testing using MS&TR, if applicable. Contractor has the manufacturer’s product data, specifications, and recommended application instructions for the concrete curing compound. Concrete strength is tested and documented for payment. Ensure the contractor has constructed contraction joints at 10’ intervals, and expansion joints at 30’ intervals. Refer to Section 03152.
D) DIVERSION BOX GATE
AND
FRAME – SECTION 02611
General Inspectors must ensure the contractor has properly installed and used the correct materials for gates and frames.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Shop Drawings 2. Installation Procedures 3. Fabrication Methods
Site Inspection Inspect the site for proper construction: 1. Material is certified per UDOT standards 2. Appropriate materials are used in construction
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Common Issues Encountered Document these common contractor mistakes: 1. Materials are not properly installed 02611: DIVERSION BOX GATE & FRAME
Pre-Inspection Items Request a copy of the approved shop drawings from the contractor. Contractor has documented concrete testing using MS&TR, if applicable. Contractor has submitted the following to the Engineer for approval at least two weeks in advance of fabrication: Diversion box screw gate and frame shop drawings Installation procedures Fabrication methods
Field Inspection Items Contractor has used the appropriate materials, such as zinc coated blades and metal frames for hand-slide grates. Contractor has installed the screw gate and frame according to shop drawings so the gate opens and closes smoothly.
E) APPROACH SLAB CATCH BASIN – SECTION 02624 General This section covers the inspection of the construction of a drainage catch basin in the approach slab of an existing structure. The contractor should properly remove existing concrete from marked work areas. The area must be properly excavated to the size and depth required by the plans. Reinforcing steel encountered during concrete removal should be cut so that the finished catch basin opening is not restricted. The catch basin should be tied to the existing approach slab and finished according to the plans. If necessary, the Engineer may adjust the location for better drainage. Page | 20
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Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Concrete Mix Design Approval 2. COC 3. Backfill Documentation
Site Inspection Inspect the site for proper construction: 1. Necessary removal of concrete is completed 2. Material is properly placed 3. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved 02624: APPROACH SLAB CATCH BASIN
Pre-Inspection Items Contractor has submitted and received approval from the Engineer for the concrete mix design. Inspector should request a copy of the manufacturer’s Certificate of Compliance (COC) for both structural steel and reinforcing steel.
Field Inspection Items Contractor has completed concrete removal, if applicable, with the proper equipment and the correct exposure of reinforcing steel for installation. Contractor has used proper materials placement including proper location, dimensions and elevation, and proper connection to pipe. Contractor has used suitable materials for backfill, depth of lift, optimum moisture and compaction. Refer to Chapter 3 of this manual. Compaction and fill requirements have been met. Backfill documentation per MS&TR Section 02056. Ensure finished basin has proper drainage.
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F) APPROACH SLAB DRAIN FRAME MODIFICATION – SECTION 02625 General This section covers the inspection of providing a frame riser to raise the existing drain grate to match the grade of the asphalt surfacing. The inspector should verify the plan dimensions for the existing grate system before the contractor begins fabrication of the new frame riser.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Verified plan dimensions 2. Buy America requirement compliance, if applicable
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved 02625: APPROACH SLAB DRAIN FRAME MODIFICATION
Pre-Inspection Items Contractor has used a galvanized frame riser. Plan dimensions for the existing grate system have been verified. Contractor has complied with the Buy America requirements, when applicable.
Field Inspection Items Contractor has galvanized the frame riser after fabrication, as specified. Materials are set to the proper elevation and direction. Hot Mix Asphalt has been properly compacted. Contractor has constructed and positioned the frame riser according to the plans. Extended pipes are properly secured.
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G) DECK DRAIN MODIFICATION
OR
CLOSURE – SECTION 02626
General The contractor must modify or close existing drains and install new drains at locations specified in the plans. Inspectors should verify the existing plan dimensions before work begins.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Verified plan dimensions 2. Buy America requirement compliance, if applicable
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved 02626: DECK DRAIN MODIFICATION OR CLOSURE
Pre-Inspection Items Contractor has used a galvanized frame riser. Plan dimensions for the existing grate system have been verified. Contractor has complied with the Buy America requirements, when applicable.
Field Inspection Items Contractor has galvanized the frame riser after fabrication, as specified. Materials are set to the proper elevation and direction. Hot Mix Asphalt has been properly compacted. Contractor closed the deck drains as shown in the plans prior to placing the new asphalt surfacing. Contractor cleaned the grate ribs and drain basin after work was completed.
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H) UNDERDRAIN – SECTION 02622 General This section covers inspection procedures for placing pipe underdrains. Inspectors should be familiar with site preparation procedures such as embankment, and types of drainage pipes and drainage geotextiles. The inspector should ensure the contractor has properly excavated the work area to the required width and depth as specified in the plans. If geotextiles are called for in the plans they should be properly installed and product data and installation information should be submitted before use. The inspector should request a copy of these submittals. Underdrain granular backfill should be properly compacted after correct placement in the prepared trench. Aggregates used should have approved source suitability. Ensure pipe is placed as called for in the plans. Generally, slots or perforations should face down and bell or grove end upstream. The spigot should be fully entered into the bell.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Material Source Approval
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Required compaction is not achieved Page | 24
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CHAPTER 4 02622: UNDERDRAIN
Pre-Inspection Items Contractor has provided geotextile product data and installation instructions. Contractor has used materials with approved source suitability for free draining granular backfill. Refer to Section 02056 and Chapter 3 of this Guide.
Field Inspection Items Inspector should ensure contractor excavated to the correct depth, and geotextiles have been properly installed, and slots are in the correct position. Inspector should ensure the free draining granular backfill is properly compacted. Refer to Section 02056 and Chapter 3 of this Guide.
4.4 RIPRAP
A) WIRE ENCLOSED RIPRAP – SECTION 02372 General This section covers the inspection of the materials and procedures for wire enclosed riprap. Wire enclosed riprap is constructed by filling modular galvanized steel wire mesh box-shaped baskets with stone on site.
Before Work Begins Before placement of the baskets, the contractor must properly prepare the subgrade by completing site-preparation activities including the removal of all brush, trees, stumps, and other objectionable materials. Unacceptable material should be removed to a depth of 1’. Refer to Section 02316. The surface should then be finished with granular borrow to bring the grade to the base of the wire enclosed riprap structure. Refer to Section 02056. The foundation must be firm and uniform to line and grade as shown in the plans. If required, the contractor should provide geotextile separation fabric. The contractor must submit the manufacturer’s product data, including typical construction details and procedures. The inspector should request a copy of this submittal and be familiar with the manufacturer’s recommendations.
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During Construction The inspector should ensure the contractor has properly built the baskets. All perimeter edges should be secured with lacing wire and binding wire should be tightly looped around every other mesh opening along the seams, alternating single and double loops. To fill, the contractor should use a loading frame, if needed, to prevent damage to the wire baskets. It may also be necessary to hand place stone around the outer edges so as not to lose smaller gradation of stones through the openings in the mesh. No stone should be greater than 10� in size. The individual baskets for all revetment designs should be assembled in such a manner that the failure and loss of stone fill from any single basket will not cause the failure and loss of stone fill in the adjoining baskets. The lids of the baskets should be secured in the same manner of tying as the assembly of the walls. Visually inspect the placement of the baskets. The contractor should begin assembly and stone placement at the lowest layer and tie each subsequent layer to the one below and the adjoining structure. Wire used in this process should be equal to that required for selvage wire. Anchors and other proprietary materials should be installed according to manufacturer’s recommendations.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Material Product Data and Installation Instructions 2. Material Source Approval 3. Wear & Soundness 4. Basket Certification
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Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Drainage is not maintained 3. Material is installed incorrectly 4. Baskets are not properly assembled
02372: WIRE ENCLOSED RIPRAP
Pre-Inspection Items Contractor has provided material product data and the installation information and procedures for wire baskets. Request copies of certifications for baskets from contractor. Visually inspect and document the assembly and installation of baskets and quality of rock to ensure contractor’s compliance with the plan specifications. Ensure that samples or submittals are in for rock source, Wear & Soundness tests. Check with the Regional Materials Lab. Inspector should ensure the contractor has properly prepared the foundation, and properly located and graded the site..
Field Documentation Items Visually inspect and document the subgrade for firmness. Other visual inspection items: basket placement to line, grade and proper order; sufficient hog rings and lacing to secure baskets and prevent deformation; and correct rock size. Visually inspect the rock to ensure it is angular, well graded, 10” minus in size, and free of seams or cracks.
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B) RIPRAP – SECTION 02373 General This section covers the inspection of the materials and procedures for loose riprap, hand placed riprap, compacted riprap, and plated riprap. Riprap is a protective layer of rock placed on earthen slopes to reduce the effects of erosion from runoff or stream scour. Materials vary from small, hand placed stones on slopes to large boulders in stream channels. The angular and irregular shape of riprap is important because it prevents the material from being carried away by runoff or scour. Inspectors should be familiar with the gradation requirements as set forth in the plan specifications and Standard Specifications. Additionally, the correct placement, layering and thickness of riprap are important to prevent water from getting into weak areas and causing erosion.
Before Work Begins Inspectors should be aware of any environmental constraints involved in the placement of riprap. These could include permits for in-stream activities, using clean equipment when working in or near streams, cleaning up any oils spills, and applicable provisions of the National Pollutant Discharge Elimination System (NPDES) permit program for storm- water discharges. Ensure the contractor has a valid SWPPP. The contractor must submit data showing riprap source gradation, Wear & Soundness, and placement technique 10 working days before use. The contractor must also submit samples for Quality Assurance testing before use of the riprap. Request copies of these submittals from the contractor. To prepare the subgrade, the contractor must properly complete site-preparation activities including the removal of all brush, trees, stumps, and other objectionable materials. The foundation must be firm and uniform to line and grade. If required, the contractor should provide geotextile separation fabric. The contractor may not over-excavate and disturb compacted foundations or undisturbed soils outside of the required lines and grades shown on the plans. Before backfilling or installing geotextiles the contractor should secure approval from the Engineer. If geotextiles are used they should be installed following Section 02075 and plan specifications. Page | 28
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During Construction Contractors using loose riprap should distribute and manipulate the stones in a manner that the larger rock fragments are uniformly distributed and that the smaller rock fragments fill the space between the larger fragments. Ensure that the toe of the slope is embedded to protect against undercutting. Contractors using hand-placed riprap should place and bed the stones to key them together and fill irregularities between the stones with suitable size stones. The finished surface should be tight and uniform when complete. The riprap should be imbedded below the ground. Loose riprap should be compacted so that it is free of any protrusions greater than 3� in height. Visually inspect the riprap materials upon delivery. It should be durable, angular, hard, stone that is free from seams, cracks, or other structural defects. If the contractor is using plated riprap, ensure it is properly placed loose riprap and compaction is complete when a uniform surface, free of protrusions greater than 4�, is observed. As always, inspectors should measure, calculate and document the quantities for payment.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. SWPPP 2. Material Source Approval 3. Material Product Data and Installation Instructions 4. Riprap Source Gradation 5. Wear & Soundness 6. Quality Assurance Test 7. Placement Technique
Site Inspection Inspect the site for proper construction: 1. Material is properly placed 2. Material is certified per UDOT standards 3. Compaction is correct 4. Environmental controls are in place
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Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Damage occurs and isn’t repaired 3. Material used is not of required quality 4. Material is installed incorrectly
02373: RIPRAP
Pre-Inspection Items Contractor has provided geotextile product data and installation information. Ensure that samples or submittals are in for rock source and Wear & Soundness tests. Check with Regional Materials Lab. Contractor has used materials with approved source suitability for riprap and the correct size (D50, Dmin and Dmax) and provided samples for quality assurance. Request copies of contractor’s submittals for riprap source gradation, Wear & Soundness, placement technique, and Quality Assurance testing. Request a copy of materials certification from the contractor to ensure that all certifications are in for geotextile fabrics. Visually inspect and document the subgrade for firmness.
Field Documentation Items Visually inspect and document the rock to ensure proper installation of rock and quality of rock. Visually inspect geotextiles to ensure contractor has used the correct material size and correct placement with proper overlap. Installation of riprap was done according to plans or detailed drawings, plan area and depth. Proper installation around pipe end section, as applicable. Proper distribution of rock to form a dense mass. Visually inspect the rock to ensure it is angular, well graded, 10” minus in size, and free of seams or cracks.
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C) GROUTED RIPRAP – SECTION 02374 General This section covers the inspection of the materials requirements and procedures for grouted riprap. The inspector should keep in mind that the source of the riprap must be tested and approved. The riprap selected must meet the gradation requirements for the intended use as specified in the plans. Refer to the Standard Specifications for a table on the size, and keep in mind that the contractor should use gradations that allow full grout penetration around the rocks.
Before Work Begins The contractor should set up a riprap source location inspection meeting with the Engineer and source material owner prior to delivering materials to project site. During this preconstruction conference the contractor must provide the proposed source site, material test results, samples for quality assurance testing before use, a grouted riprap sample pan- el, the grout mix design, and a Quality Control Plan. The contractor should also identify a stockpiling procedure and location. Stockpile prevention plans should be determined in the SWPPP. The contractor must provide written certification verifying the quality of riprap existing at the industrial source. Many tests must be performed on the aggregate before certification and the inspector should request copies of all these submittals. The contractor must certify that “reactive” stones are not found in the quarry pit by sending samples to the Materials Lab for testing, if required. Alkali-silica and alkali- arbon reactions are the most frequent of these reactions so the contractor must perform an alkalinity test and perform a petrographic analysis on representative aggregate samples to determine whether reactive stones are present, in the absence of a documented 10 year history of use of quarry aggregates in commercial concrete mix designs. If a documented history is present, the contractor should provide historic results on reactivity of the rock. The contractor must also perform a percolation test, sieve analysis, petroleum distillates test, and a LA wear test. The contractor must use grout that conforms to requirements of Section 02374 and has an approved mix design. Geotextiles and bedding materials must also conform to requirements and be installed according to manufacturer’s instructions or plans. Bedding aggregate under riprap must be at least 6” thick.
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Site preparation is important before placement of grouted riprap. This includes installing surface and ground water control measures to ensure dry conditions during construction and ensuring that natural drainage areas are not compromised. As is the case with all site preparations, the contractor must remove all topsoil, loose excavated materials, vegetative debris, concrete debris, and other objectionable materials from beneath the areas where the grouted riprap is to be placed. The subgrade should be compacted to 95% maximum density, AASHTO T 99, or to a 70% relative maximum density, AASHTO T 180. The contractor must perform surface and ground water control measures as needed to ensure dry work area conditions. Water control measures include, but are not limited to diversions, culverts, sumps with pumps or other means necessary to maintain the level of groundwater below subgrade elevation and to divert surface water away from the work area. The contractor must not block natural drainage layers or horizons within the channel bottoms.
During Construction After proper site preparation, approved materials should be placed and compacted as specified in the plans to the designated subgrade elevation. The contractor should not backfill depressions with shattered shale materials. Fill materials should be spread uniformly to minimize segregation. The graded areas should be smoothed to maintain the specified slope with no more than 3â€? change, unless closer tolerances are specified. The contractor should place a free draining bedding layer around the weep drains and provide suďŹƒcient cover to prevent crushing by riprap. The contractor must also place bedding materials prior to placement of riprap. The contractor should notify the Engineer before placing riprap elements over bedding layer because the Engineer must first verify compaction requirements have been met. If geotextiles are used, they must be undamaged, properly overlapped, and have a minimum of 3â€? of bedding aggregate over the fabric. These materials should also be approved. Then the riprap materials can be placed on the prepared site. The contractor should begin placing stones at the lowest point, and remove any stones protruding more than 10% of the stone layer thickness. Large stones should be distributed uniformly to provide adequate access for the grout to the lower portions of the stone to prevent voids from forming. Check for minimum thickness and height indicated in the plans, and ensure the finished outer edges are level with the adjacent ground. Page | 32
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CHAPTER 4 Finally, the riprap can be grouted after it is properly in place. The contractor must not place the grout if the temperature is less than 40 F or on frozen surfaces. The temperature should be between 50 F and 90 F. during the placement and curing period. The grout must penetrate to the subgrade and fill all voids while leaving the top of the stones fully exposed. To ensure proper curing and protection the contractor must keep all exposed surfaces continuously moist for 7 days and protect from becoming damaged.
Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. SWPPP 2. Materials Lab Approval 3. Material Source Approval 4. Material Product Data and Installation Instructions 5. Quality Control Plan
Site Inspection Inspect the site for proper construction: 1. Subgrade is prepared 2. Material is properly placed 3. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Density requirements are not achieved 3. Moisture is not maintained 4. Material is installed incorrectly
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02374: GROUTED RIPRAP
Pre-Inspection Items Contractor has used materials with approved source suitability for riprap and the correct size (D50, Dmin and Dmax) and provided samples for quality assurance. Ensure that samples or submittals are in for rock source, Wear & Soundness tests, and grout mix design. Check with the Regional Materials Lab. Petrographic analysis of the proposed materials is submitted, if required. Request copies of certifications of all other materials from the contractor.
Field Inspection Items Rock is clean and free of clay or foreign material and thoroughly wetted to a saturated surface condition before grouting. Contractor has properly placed bedding materials. Contractor has used the proper placement and consolidation of grout. Contractor has provided a compacted subgrade and gained approval from the Engineer. Ensure a density test has been performed and documented. Contractor has used an approved grout mix design. Installation of riprap is done according to plans or detailed drawings, plan area and depth. Contractor kept all exposed surfaces continuously moist for 7 days and protected from becoming damaged to ensure proper curing. Final visual inspection and documentation of proper installation of fabric, rock, and grout.
D) EROSION CONTROL BLANKETS/CHANNEL LINERS – SECTION 02376 General This section includes inspection procedures for erosion control blankets and fabrics. These materials include fabrics applied on slopes to prevent soil erosion and protect the seed- bed. They are usually machine-produced fabrics consisting of elongated wood, coconut fibers, or straw bonded together. A flexible channel liner is a machine produced mat consisting of elongated materials that are bonded together and used to line channels. As with geotextiles, the materials have to be approved before use and meet plan specifications. The contractor must submit a sample of the blanket or liner, staples and other materials used to the Engineer for approval. The manufacturer’s specifications and recommended installation requirements need also be submitted. The inspector should request copies of these submittals and be familiar with the recommended installation procedures. Page | 34
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Submittal Requirements Prior to performing inspection, request copies of the following documents: 1. Material Product Data and Installation Instructions 2. Material Source Approval
Site Inspection Inspect the site for proper construction: 1. Material is properly placed and installed 2. Material is certified per UDOT standards
Common Issues Encountered Document these common contractor mistakes: 1. Site isn’t properly prepared before installation 2. Damage occurs and isn’t repaired 02376: EROSION CONTROL BLANKETS/CHANNEL LINERS
Pre-Inspection Items Contractor has provided manufacturer’s product data and installation instructions. Contractor has submitted proper samples of materials to be used for approval.
Field Inspection Items Inspector should ensure contractor has removed all vegetation before placement, anchored the material as it is rolled out, used sufficient anchors, properly buried the edges, and in- stalled the materials according to the manufacturer’s recommendations.
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Construction Inspection Guide Chapter Links
1-Preface & Introduction
2-Traffic Control
3-Demolition and Earthwork
4-Drainage
5-Pavement & Materials
6-Structures
7-Traffic Signals, Lighting, ATMS
8-Striping, Signing, Safety Features
9-Landscaping, Fencing, Incidental Const.
10-Utilities
11-PDBS
12-Crash Cushion & Barrier End Treatments
Construction Inspection Guide
udot.utah.gov/go/construction