(1. Central South University，Changslia，Hunan 410075，China; 2. Shanghai - Kunming Railway Passenger Dedicated Line Zhejiang Co. Ltd，Hangzhou，Zhejiang 310019，China; 3. The Third Railway Survey and Design Institute Group Corporation，Tianjin 300251，China)
Abstract：Abstract ： Research purposes ： The detrimental effect of adjacent unsupported excavation on bridge pile foundation usually degrades the operation quality and security of high speed railway. A series of field prototype tests had been performed to investigate the behavior of pile groups in deep soft clay subjected to adjacent excavation in three working conditions. The ABAQUS finite element software had been adopted to execute the three dimensional numerical simulation of t!ie process of field tests. By comparing test results wit!i those from numerical analysis，the rationality of established finite element model and adopted calculation parameters in this paper was verified. Then the influences of excavation conditions (the excavation width，the distances between the pile foundation and the excavation，the excavation depth) on pile response were investigated. Research conclusions ：( 1 ) The distrilDution range of deformation and internal force of piles induced by adjacent excavation is 2. 1 ?2. 8 times as long as that of active piles in design，which deteriorates the piles performance and high attention should therefore be paid to it in operation and maintenance of high speed railway. (2) When the excavation width exceeds 5 times of tlie distance between the pile foundation and the excavation ; the effects of increasing sequential excavation width on pile response could be neglected. ( 3 ) When the distance between the pile foundation and the excavation exceeds 30 m ( roughly 6 times of tlie excavation width) ; the pile responses induced b: narrowand shallow excavation can be neglected in engineering practice. (4) The horizontal displacement of pile top and the maximum bending moment increase exponentially with the increase of the ratio h/b and the smaller the distance is，the higher the growth rate is. (5) The research results can be used for the design，construction，operation and maintenance of pile foundation of high - speed railway bridge.
2017, Vol. 34 
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