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| Control effect of cross walls on metro foundation pit deformation induced by pre-excavation dewatering in soft soils |
| ZENG Chaofeng1，2，WANG Shuo1，SONG Weiwei1，LI Miaokun1，XUE Xiuli1，MEI Guoxiong2 |
| (1. Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring，Hunan University of Science and Technology，Xiangtan，Hunan 411201，China；2. Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education，Guangxi University，Nanning，Guangxi 530004，China) |
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Abstract At present，most studies in the field of foundation pits ignore the wall deflection caused by pre-excavation dewatering(PED). How to effectively control such deformation is of great significance to the construction of deep foundation pits in soft soils. In this study，an idea of rationally arranging cross walls for deformation control is proposed. Through laboratory-scale tests and numerical simulations，the effectiveness of the cross wall in reducing the foundation pit deformation induced by PED is investigated，and the influence of the cross wall spacing on the deformation control effect is discussed. Results show that the deformation control of a single cross wall has a certain range of influence，about 30 m apart from both sides of the cross wall in this paper. The deformation control effect is strongest at the cross wall location and gradually weakens with increasing the distance from the cross wall. It is also indicated that，when the cross wall spacing d is smaller than 5 times the width of the foundation pit B，the restraint effect of the cross walls on the overall pit deformation begins to appear，and that，when d is smaller than 3B，the cross walls will show apparent effect in restraining pit deformation induced by PED. It is suggested that the overall deformation of the foundation pit can be controlled through the superimposition effect of the deformation restraint of adjacent cross walls by setting a reasonable cross wall spacing.
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2021, Vol. 40 
