墙后填土液化前后对挡土结构物的总压力分析  

Analysis of the Total Pressure of Backfill Soil before and after Liquefaction behind a Retaining Wall

作　　者：高晓静[1] 许成顺[1,2] 杜修力[1,2] 

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [2]首都世界城市顺畅交通北京市协同创新中心,北京100124

出　　处：《防灾减灾工程学报》2017年第2期237-242,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB013600);国家自然科学基金项目(51278015);国家自然科学基金创新研究群体项目(51421005)资助

摘　　要：针对墙后填土液化前后对挡土结构物总压力的变化情况进行了分析。墙后填土液化后孔隙水压力升高、有效应力降低,土颗粒处于悬浮状态,此时不存在土压力。由于液化后墙后填土呈现出粘性流体的性质,其对挡土结构物的作用力等同于以土体饱和重度γsat为重度的粘性流体以各方向相同的力作用在挡土结构物上,因此液化后挡土结构物上的总压力明显增大,工程中应予以重视。计算结果表明:随着地下水位的下降,墙后填土液化前、后对挡土结构物的总压力均逐渐减小,但液化后与液化前的总压力比值呈先增大后减小的变化趋势;随着静止土压力系数K0的增大,墙后填土液化前后对挡土结构物的总压力逐渐增大(完全浸水情况下,液化后的总压力不随静止土压力系数K0的变化而变化),但液化前的总压力增长更快,故液化后与液化前总压力的比值呈减小的趋势。The variation of the gross pressure of backfill soil before and after liquefaction behind a retaining structure was analyzed. The pore water pressure becomes higher after the backfill soil behind a retaining structure is liquefied, while the effective stress decreases. Also, the earth pressure is disappearing while the soil particles are suspended. Due to that groundwater has char- acteristics of viscous fluid, the earth pressure acting on the retaining wall equals to the force iso- tropically that is applied by the viscous fluid with a saturated gravity of ~ So the gross pressure of the backfill soil on the retaining structure increases evidently in the post liquefaction stage. More attention should be paid in this stage. Results indicate that the gross soil pressure before and after liquefaction reduce as the underground water level moves down, but the ratio of the gross pressure presents the trends which first increase then decrease. With the increase of the pressure coefficient K0, the gross pressure increases gradually （In the case of entirely emerged in water, the pressure coefficient will be stable）. Since the gross pressure before liquefaction increa- ses faster, the pressure ratio becomes smaller as the pressure coefficient increases.

关 键 词：墙后填土 液化 粘性流体 总压力 土压力 

分 类 号：TU435[建筑科学—岩土工程]