CAJ | 학술논문

采用合适的计算方法确定有效的围护方案是基坑设计中的难点.以南京纬三路过江隧道江北盾构工作始发井为依托,采用空间地基板法反演分析得到各地层m值,通过编制DLOAD子程序实现主动区与被动区的判别和相应荷载的施加,得到坑外降水条件下软土地层深大盾构工作井围护体系的受力与变形特征.计算结果与现场实测值较为吻合,从而证明采用空间地基板法配合反演得到的地层m值可有效预测工作井围护体系的变形与受力特征.为进一步优化设计方案,选定连续墙厚度、支撑截面尺寸及底板以下5 m范围内土体m值3个参数,通过正交试验进行参数分析,得到影响连续墙水平位移及支撑轴力的主要因素.计算方法及相关计算结果可为同类工程设计提供参考.
채용합괄적계산방법학정유효적위호방안시기갱설계중적난점.이남경위삼로과강수도강북순구공작시발정위의탁,채용공간지기판법반연분석득도각지층m치,통과편제DLOAD자정서실현주동구여피동구적판별화상응하재적시가,득도갱외강수조건하연토지층심대순구공작정위호체계적수력여변형특정.계산결과여현장실측치교위문합,종이증명채용공간지기판법배합반연득도적지층m치가유효예측공작정위호체계적변형여수력특정.위진일보우화설계방안,선정련속장후도、지탱절면척촌급저판이하5 m범위내토체m치3개삼수,통과정교시험진행삼수분석,득도영향련속장수평위이급지탱축력적주요인소.계산방법급상관계산결과가위동류공정설계제공삼고.
@@@@It is difficult to choose an appropriate calculation method to determine the effective enclosure system in foundation pits design. This case study deals with the excavation of Jiangbei shield working shaft of Weisan road over-river tunnel in Nanjing,which is a typical deep working pit in soft soil strata. The spatial foundation plate method was used to analyze the deformation and stress condition of the structure of the shield working pit under dewatering outside the foundation pits. The m values of strata are obtained through back analysis;and the active and passive areas were judged by the DLOAD subroutine. The calculation results are consistent with the measured results;so the spatial foundation plate method with m values from back analysis can effectively predict the deformation and stress behavior of the enclosure structure. In order to further optimize the structure,three factors, i.e. thickness of diaphragm wall,size of supporting section and m value of soils within 5 m below the floor,are selected for orthogonal array experiment;and the main influencing factors of horizontal displacement of diaphragm wall and axial forces of bracings are obtained. The calculation method and the relevant results can provide references for similar engineering.