富水砂卵石层深基坑近接建筑物安全施工控制技术研究  

Study on Safety Control Technology of Deep Foundation Pit Construction Near Buildings in Water-soaked Sand and Cobble Stratum

作　　者：潘世强[1] 邓俊[2] PAN Shiqiang;DENG Jun(Hunan Communications Research Institute,Changsha,Hunan410015,China;School of Givil Engineering,Central South University,Changsha410075,China)

机构地区：[1]湖南省交通科学研究院,湖南长沙410015 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《公路工程》2018年第3期173-178,共6页Highway Engineering

基　　金：湖南省科技厅课题(2014SK4072);湖南省交通厅课题(201432)

摘　　要：依托某一典型富水砂卵石基坑工程,通过数值计算对近接建筑物地铁基坑开挖过程中基坑渗流及建筑物沉降进行了分析,并基于现场注浆试验得到合理的基坑基底注浆加固方案,最后通过基坑施工现场实测分析了加固措施的有效性。研究结果表明:富水砂卵石地层深基坑施工会导致在基坑开挖深度范围内及基底一定区域内形成明显的降水漏斗,造成基坑外水位大幅下降且在坑角处渗流最为显著,极易影响基坑边坡稳定性;基坑施工引起的建筑物沉降大,极易导致建筑物发生不均匀沉降破坏;富水砂卵石地层注浆孔距应控制在1.8 m左右,以保证孔间土体能够加固密实;基坑底部采取注浆加固措施能有效地减小基坑施工对建筑物的影响,基坑开挖结束时建筑物最大沉降值为-8.56 mm,工程顺利完成;研究成果可为类似基坑工程施工提供一定依据。Based on a typical sand and gravel foundation pit project,this paper analyzes the seepage of foundation pit and the settlement of the building during the foundation excavation of the subway; And based on the field grouting test,a reasonable foundation pit grouting reinforcement program is getten; And finally through site analysis of the foundation pit construction,the effectiveness of reinforcement measures is analyszed. The results show that： The construction of the deep foundation pit in watersoaked sand and cobble stratum will lead to the obvious precipitation funnel within the depth of excavation and the certain area of the substrate which results in a significant decrease of the water level outside the foundation pit; Without reinforcement measures,the pit angle is at the most obvious seepage,which is easy to affect the stability of the foundation pit slope during the pit excavation process; Construction of foundation pit will cause the large settlement of buildings,which can easily lead to uneven building settlement damage; The water-filled sand and gravel layer should be controlled at about 1. 8 m to ensure that the soil between the holes can be strengthen densely. The grouting reinforcement measures of the bottom of the pit can effectively cut off the infiltration of the pit inside and outside the pit and the maximum settlement value of the building at the end of excavation is-8. 56 mm,which thus reduces the impact of excavation on the building to ensure the successful completion of the project; The results of this study can provide some basis for construction of similar pit engineering.

关 键 词：富水砂卵石地层 地铁深基坑 近接建筑物 变形控制 注浆加固 

分 类 号：TU753[建筑科学—建筑技术科学]