摘要
为解决冻土地区越冬基坑保温防护设计难题,针对哈尔滨地铁3号线会展中心站深基坑,基于FLAC^(3D)软件模拟研究了越冬期基坑温度、水平位移和水平冻胀力的变化规律。开展正交试验探究了冷端温度、降温时长和围护桩刚度3个重要因素对基坑水平冻胀力的影响,提出了针对性的防护措施。研究结果表明:基坑水平冻胀力对侧壁水平位移影响显著,侧壁部分位置水平冻胀力超过规范允许值;冷端温度对水平冻胀力大小影响最为显著,为满足规范要求,冷端温度应控制在-13℃以上。现场监测结果表明,基坑变形和整体稳定性符合模拟结果,依据正交试验结果设计的保温措施效果较为理想。研究成果可为严寒地区深基坑的越冬防护提供参考。
For solving severe cold protection problems of foundation pits in freezing soil area,the variation laws of foundation pit temperature,horizontal displacement and horizontal frost heaving force during overwintering period were studied by simulating the deep foundation pit in Exhibition Center Station of Harbin Metro Line 3.Orthogonal experiments were carried out to explore the effects of cold end temperature,cooling time and retaining pile stiffness on the horizontal frost heaving force of the foundation pit.Based on this,targeted protection measures were put forward.The results show that the horizontal frost heaving force of foundation pit has a significant effect on the displacement of side wall.The horizontal frost heaving force at some positions of side wall exceeds the allowable value of the code.Besides,the cold end s temperature has the most significant effect on the horizontal frost heaving force.In order to meet the specification requirements,the cold end s temperature should be controlled above-13℃.The field monitoring results show that the deformation and overall stability of the foundation pit complies with the simulation results,and the effect of the thermal insulation measures designed according to the orthogonal experimental results is ideal.The research results can provide reference for the overwintering protection of deep foundation pit in severe cold area.
作者
吴忠鑫
苗胜军
隋智力
刘泽京
WU Zhongxin;MIAO Shengjun;SUI Zhili;LIU Zejing(Civil and Resource Engineering School,University of Science and Technology Beijing,Beijing 100083,China;Department of Urban Construction,Beijing City University,Beijing 100083,China)
出处
《人民长江》
北大核心
2022年第11期136-142,共7页
Yangtze River
基金
国家自然科学基金项目(51974014,51574014)。
关键词
越冬基坑
水平冻胀力
数值模拟
正交试验
现场监测
foundation pit construction during overwintering period
horizontal frost-heave forces
numerical simulation
orthogonal test
field monitoring
