短时吊车荷载对超深工作井基坑变形影响分析  

Impact Analysis of Short-term Crane Loading on Ultra-deep Working Shaft Foundation Pit Deformation

作　　者：李春林 刘燕 虞涛[3] 王浩 方正 邵玉婷 LI Chunlin;LIU Yan;YU Tao;WANG Hao;FANG Zheng;SHAO Yuting(Jinan City Construction Group Co.,Ltd.,250031,Ji’nan,China;不详)

机构地区：[1]济南城市建设集团有限公司,济南250031 [2]山东省城市地下工程支护及风险监控工程技术研究中心,济南250022 [3]济南大学土木建筑学院,济南250022 [4]山东省土木建筑学会,济南250002

出　　处：《城市轨道交通研究》2023年第12期85-89,共5页Urban Mass Transit

基　　金：国家自然科学基金项目(51979122);山东省自然科学基金面上项目(ZR2022ME042)。

摘　　要：目的:为了充分认识超深盾构工作井基坑施工过程中的安全性,应密切关注施工中坑顶行车、吊装等短时频繁的施工荷载对基坑变形和安全性的影响。方法:以济南黄河隧道工程南岸超深工作井基坑为研究背景,采用现场实测数据和数值模拟相结合的方法,研究不同吨位吊装荷载在基坑施工过程中对支护结构变形的作用规律。结果及结论:研究表明,坑边荷载对变形的影响与荷载大小及作用时间有关,荷载消失后地下连续墙变形会有50%左右的回弹量,荷载值越小,作用时间越短,回弹量越大,且大部分回弹约在3 h内完成。但仍有50%的变形不可恢复,荷载的多次频繁的短时作用,使得这种变形不断累积,因此,简单的对坑顶施工荷载进行拟静力化的设计,有可能使得基坑支护结构存在安全隐患。Objective:To comprehensively understand the safety aspects of the construction process of ultra-deep shield working shaft foundation pit,close attention should be paid to the frequent short-term construction loads,such as pit top vehicle passing and crane operations,and their impact on the deformation and safety of foundation pit.Method:Using the ultra-deep working shaft foundation pit on the south bank of Ji′nan Yellow River Tunnel project as research background,a combined approach of field measurements and numerical simulations is employed to study the impact law of different tonnage crane loads on the deformation of the supporting structure during pit construction process.Result&Conclusion:It is indicated that the impact of edge loads on deformation is related to the load magnitude and duration.After the load disappears,there is approximately a 50%rebound in the deformation of underground diaphragm wall,with smaller loads and shorter durations resulting in larger rebound amounts.Most rebound occurs within approximately 3 hours.However,about 50%of the deformation remains unrecoverable.The cumulative effect of multiple short-term load applications may lead to continuous deformation accumulation.Therefore,simplistic quasi-static designs for pit top construction loads may pose safety risks to the foundation pit supporting structure.

关 键 词：超深基坑 短时荷载 现场试验 数值模拟 地下连续墙 

分 类 号：TU441.6[建筑科学—岩土工程]