摘要
黄土地区城市地铁建设中,降水是保障自身施工安全的重要措施,但对周边环境会造成威胁,必要时需采取停止降水的应急措施。依托两个典型工程,首次研究了停止降水后建筑物和地表变形的发展规律、地下水位的回升情况、水位回升后再次湿陷的可能性及结构自身安全稳定等影响能否停止降水的关键问题,并制定了停水前应采取的一系列技术措施。研究表明:停止降水后,建构筑物和地表变形能够得到有效控制,并出现一定的回弹,上覆荷载越大,回弹变形量越小;停止降水后,水位回升经历迅速上升到缓慢上升再到逐步稳定的三个阶段;在上覆压力未增大的情况下,水位回升不会引起湿陷变形;水位回升后,地铁自身结构稳定无法保证,应增加二衬和基底注浆的技术措施。
During the construction of urban subway in the loess area,precipitation is a effective measure for its construction safety.However,it will pose a threat to the surrounding environment,so it is necessary to take emergency measures to stop precipitation when necessary.Based on two typical projects,through on-site monitoring and calculation analysis,this paper analyzed the development law of building and surface settlement after stopping dewatering,the recovery of groundwater level,the possibility of collapsing after the water level rises,the safety and stability of subway structure,and other significant issues that affect whether the dewatering can be stopped,and formulates the technical measures that should be taken before stopping dewatering.The results are as follows.After the stop of precipitation,the building and surface deformation can be effectively controlled,and there is a specific rebound.The more significant the overlying load is,the smaller the rebound deformation is;The rise of water level goes through three stages:rapid rise,slow rise and then stable;The rise of water level will not cause collapsible deformation when the overlying pressure remains unchanged;After the rise of water level,the ground subsidence will be reduced.The stability of the iron structure cannot be guaranteed,so the technical measures of adding a secondary lining and base grouting is highly recommended.
作者
于文龙
亢佳伟
邓国华
YU Wenlong;KANG Jiawei;DENG Guohua(Guangzhou Metro Design and Research Institute Co.,Ltd.,Guangzhou,Guangdong 510010,China;Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Xi’an Loess Underground Project Technology Consulting Co.,Ltd.,Xi’an,Shaanxi 710000,China)
出处
《水利与建筑工程学报》
2022年第4期197-203,共7页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金项目(52178355)。
关键词
饱和软黄土
降水
水位回升
固结沉降
环境风险
saturated soft loess
precipitation
water level rising
consolidation settlement
environmental risk
