CIVIL & STRUCTURAL ENGINEERING
ADVANCED HAT SOLUTIONS FOR MANPOWER REDUCTION AND
COST-EFFECTIVE CONSTRUCTION OF EARTH RETAINING AND STABILISING STRUCTURES by Kazutaka Otsushi, Senior Manager, Nippon Steel Southeast Asia, Singapore; Kelly Lim Swee Chin, Senior Civil Engineer, Nippon Steel Southeast Asia, Singapore; and Zac Chen, Marketing, Nippon Steel Southeast Asia, Singapore
Mr Kazutaka Otsushi
Ms Kelly Lim Swee Chin
Mr Zac Chen
In Singapore, steel sheet pile/soldier pile walls are generally constructed where there is need for temporary retaining walls. For this, the Hat Sheet Pile with 900 mm was described in the BCA design guide (BC1:2012) as JIS A 5523 grade, in Year 2012. Since then, it has further developed into Advanced Hat Solutions with the Hat Soldier Pile (non-welding type) and Hat + H Pile (combined by welding type). The Hat + H type has been adopted by LTA, for the construction of retaining walls in MRT projects. This article will explain the different technical aspects of Advanced Hat Solutions, their features, applications in construction to improve construction productivity, and innovative methods for pilling works in hard soil layers. INTRODUCTION The Hat type with H-beam solutions have strong track records in many countries, including in ASEAN countries (Singapore, Philippines and Indonesia) as well as in the US, China, India and other countries, in applications such as the construction of wharves/ river revetments, underground temporary walls, retaining walls, water cofferdams etc.
(a) Non-welding type
For Advanced Hat Solutions, which are used in excavations of more than 10 m in depth, there are two main types - one is the Hat Soldier Pile (Hat with H-beam without welding) and Hat+H Pile (Hat with H-beam combined with welding).
SERIES OF HAT TYPE SHEET PILE SOLUTIONS Based on the required stiffness, the most suitable solutions can be selected with Hat sheet pile technology. The Hat type has four sizes, namely, 10H, 25H, 45H and 50H. If a higher wall stiffness is required in the design of Earth Retaining and Stabilising Structures (ERSS), Advanced Hat Solutions (Hat type with H-beam solutions) are recommended (Figure 1). 20
THE SINGAPORE ENGINEER May 2021
b) Combined by welding type Figure 1: Hat with H-beam solutions
HAT Soldier Pile (non-welded type) The Hat with H-beam (non-welded type), namely the Hat Soldier Pile, is the same system as the conventional Soldier Pile but with a different sheet pile as lagging. For this, the
