土工泡沫减压膨胀土挡墙侧向压力及影响因素分析  

Model test and influence factors analysis of lateral pressures on expansive soilretaining wall with expanded polystyrene geofoam inclusions

作　　者：邹维列[1] 樊科伟 张攀 韩仲 ZOU Wei-lie;FAN Ke-wei;ZHANG Pan;HAN Zhong(School of Civil Engineering,Wuhan University,Wuhan,Hubei 430072,China;Key Laboratory of Geomechanics and Embankment Engineering of Ministry of Education,Hohai University,Nanjing,Jiangsu 210098,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098

出　　处：《岩土力学》2023年第9期2537-2544,2554,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51979206);国家重点研发计划(No.2019YFC1509800);江苏省卓越博士后计划(No.2023ZB830);湖北省自然科学基金(No.2021CFB389)。

摘　　要：墙后膨胀性填土在吸水膨胀后,将对挡墙产生较大的侧向压力,严重时可能引起挡墙失稳。在墙背与膨胀性填土之间铺设可发性聚苯乙烯土工泡沫(expanded polystyrene geofoam,简称EPS)缓冲层,利用EPS的高压缩特性,为填土的侧向变形提供空间,可有效减小作用于挡墙的侧向压力。为了探明墙后铺设EPS的膨胀土挡墙在膨胀土浸润至饱和状态时,侧向压力沿墙高的分布规律及影响因素,开展了EPS减压膨胀土挡墙模型试验和相应的理论分析。结果表明:(1)当膨胀土浸润至饱和时,铺设密度为12 kg/m3的EPS可减小膨胀土挡墙约50%的总侧向压力;(2)无EPS的膨胀土挡墙的侧向压力沿墙深逐渐增大,而含EPS的膨胀土挡墙的侧向压力沿墙深基本相同;(3)EPS厚度越大,密度越小,对挡墙侧向压力的减压效果越好。Expansive soils,known for their considerable swelling pressure upon wetting,have been identified as potential instigators of instabilities in retaining walls.The incorporation of expanded polystyrene geofoam(EPS)inclusions between the retaining wall and the backfilled expansive soil has been found to considerably mitigate the lateral pressure on the wall,which results from the water absorption and expansion of the expansive soil.This substantial reduction is due to the impressive compressibility of the EPS inclusion.To explore the implications of the EPS inclusion on the lateral pressure distribution on retaining walls,and to analyze the factors influencing this pressure,a comprehensive model test and a corresponding lateral pressure theoretical analysis were performed.The results show that(1)the total lateral pressure acting on the retaining wall was reduced by about 50%by the EPS inclusion with a density of 12 kg/m3 when the expansive soil is saturated in the model test;(2)in the absence of the EPS inclusion,the lateral pressure distribution acting on the retaining wall escalated along its depth,whereas with the EPS inclusion,it remained largely uniform throughout the wall’s depth;(3)the lateral pressure reduction due to the EPS inclusion was enhanced with increasing thickness and decreasing density of the EPS inclusion.

关 键 词：挡土墙 膨胀土 土工泡沫 模型试验 侧向压力 

分 类 号：TU473[建筑科学—结构工程]