Global journal 41

Page 1

www.globaljournal.asia

GJESR RESEARCH PAPER VOL. 1 [ISSUE 10] NOVEMBER, 2014

ISSN:- 2349–283X

LIQUEFACTION HAZARD ASSESSMENT OF RAMGARH TAL PARIYOJNA 1Abhishek

Kumar Tiwari Department of Civil Engineering, Madan Mohan Malviya University of Technology, Gorakhpur, India Email: abhicivilengg07@gmail.com

2Dr.S.M

Ali Jawaid Department of Civil Engineering, Madan Mohan Malviya University of Technology, Gorakhpur, India Email: smaj@rediffmail.com

ABSTRACT: Determination of liquefaction potential due to earthquake is complex geotechnical problem. Many factors including soil parameters and seismic characteristics influence this phenomenon. The devastating damage of liquefaction induced ground failures in the Alaska 1964 and Niigata 1964 earthquakes serve as a clear reminder of such events. Liquefaction is one of the ground failures in potential earth science hazard. Since Gorakhpur falls in the area with high seismic probability, there is need for the assessment of liquefaction potential, so the study area is “Ramgarh Tal Pariyojna” to recognize the conditions that exist in a soil deposit before an earthquake in order to identify liquefaction. Results of an extensive analysis for determination of liquefaction hazard analysis of “Ramgarh Tal Pariyojna of Gorakhpur city at different locations is addressed here. The simplified procedure suggested by seed & Idriss (1971) on the basis of field performance data is used for determination of liquefaction potential and also to present a liquefaction hazard map using SPT data collected from the various sites at different locations of “Ramgarh Tal Pariyojna”. From the analysis it is observed that the areas with river channel deposit are the most hazardous area for liquefaction. From the study it is also concluded that if acceleration level is increased then more area will be affected due to liquefaction. In this study we concluded that if earthquake more than or equal to 6.5 ritcher scale occurs in Gorakhpur region, it will be extensively damaged due to liquefaction. The percentage of silt and poorly graded sand is high in the area under “Ramgarh Tal Pariyojna” indicating that there is a great chance of soil liquefaction. Here liquefaction potential analysis is done to determine the factor of safety at different depth. The structure constructed should be liquefaction resistant i.e., designing the foundation elements to resist the effects of liquefaction if at all it is necessary to construct the structure on liquefiable soil because of favourable location, space restriction and other reasons. Keywords: Liquefaction, microzonation, standard penetration test, Seismic Hazard 1. INTRODUCTION Gorakhpur lies between Latitude 26˚ 13´ N and 27˚29´N and long.83˚05´E and 83˚56´E.the district occupies the north-eastern corner of the state along with the state of Deoria, & comprises a large stretch of country lying to the north of river Ghaghra, the deep stream of which forms its boundary with district Azamgarh. In the earthquake zonal map of India the district lies in zone IV liable to moderate damage by earthquakes. Although no major earthquake occurred close to it, the tract being not far from the Great Himalayan Boundary fault, experiences the effects of moderate to great earthquake occurring there. The seismic intensity may not exceed VIII on the Modified Mercalli 1931. As India experiencing lots of seismic threats and Liquefaction is one of the major types for ground failure. Liquefaction is a soil behaviour phenomenon in which a saturated soil losses a substantial amount of

strength due to high excess pore-water pressure generated by and accumulated during strong earthquake ground shaking. Large numbers of liquefaction studies were conducted in all the earthquake prone areas of the world. After the 2001 Bhuj earthquake, attracted the great attention of liquefaction studies. Soil liquefaction has been a major cause of damage to soil structure, lifelines and building foundation. Zoning for liquefaction, therefore, has been an important goal for seismic hazard mitigation. Gorakhpur region is potentially prone to damaging earthquakes, as it is located in an active seismic zone IV. Because of the haphazard urbanization and increasing population in the Gorakhpur region now, it has become very essential to carry out studies on different aspects of the earthquake hazard leading to long term earthquake vulnerability reduction

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