北京平原区地下空间建设地质安全监测问题探讨  

Research on geological safety monitoring of urban underground space resource utilization in Beijing

作　　者：周圆心 郑桂森[2] 何静[1] 李超[1] 刘予[1] 何晗晗 肖景泽 ZHOU Yuanxin;ZHENG Guisen;HE Jing;LI Chao1;LIU Yu;HE Hanhan1;XIAO Jingze(Beijing Institute of Geological Survey, Beijing 100195, China;Beijing Geological Prospecting and Developing Bureau, Beijing 100195, China)

机构地区：[1]北京市地质调查研究院,北京100195 [2]北京市地质矿产勘查开发局,北京100195

出　　处：《中国地质》2019年第3期455-467,共13页Geology in China

基　　金：北京市地质矿产勘查开发局项目(PXM2017_158203_000006)资助~~

摘　　要：北京平原区地质条件复杂,冲洪积扇及冲洪积平原相互交织、软弱土体(人工填土、软土)大面积分布,且浅表层地下水流场多变、各类地质灾害发育(活动断裂、地面沉降等),加大了地下空间建设难度,建设完成后易发生各类事故。如软弱土体地层稳定性较差,易发生较大地层形变甚至地面塌陷,破坏地下建(构)筑物结构;地下水水流场的变化,影响地下空间的抗浮稳定性及防渗性,在施工中可能遭遇突涌、施工中断甚至人员伤亡等严重后果;活动断裂产生的三维空间形变,兼具张拉、剪切和扭动的性质,使跨断裂的地下隧道变形,甚至能造成衬砌的断裂;地面沉降发生面积和沉降速率都呈上升的趋势,跨不均匀沉降区建设的地下轨道受沉降影响,出现异常位移或基础破坏等现象。同时,地下空间的建设,对其周边地质环境也会产生作用,产生一系列环境地质问题。如地下空间施工建设措施不当,改变岩土体原有的应力平衡,导致土体位移,产生地表沉降或变形,导致建筑物失稳、甚至破坏;砂质粉土黏粒含量少,饱和状态下受地铁振动易发生液化、流砂;地下管线的渗漏导致地下水受到污染;地下大型线性工程的建设阻断地下水流场,改变地下水环境等。本文拟阐述地质条件对地下空间建设的影响以及地下空间建设可能产生的地质环境问题,从这两个方面出发,提出地下空间建设监测的对象、监测体系及监测方法手段,研究地下空间建成后的地质安全保障。Geological conditions in Beijing plain area are extremely complicated, involving interlaced alluvial-pluvial fan and plain as well as widespread weak soil layers(e.g., made ground, soft soils), which leads to changeable shallow groundwater flow field and various geological hazards such as active faults and land subsidence, thus increasing the difficulty of underground space construction and accident probability. The weak soil layers normally have poor stability, which may cause large degrees of stratigraphic deformation or even collapse and hence destroy the underground structures;in addition, the change of groundwater flow field can affect the anti-floating stability and impermeability of underground space, and may result in serious damages such as gushes during constructions;the active faults, which can cause three-dimensional spatial deformation with properties of tension, shear and torsion,are likely to deform underground tunnels or even lining fractures;meanwhile, the increasing ground subsidence area and subsidence rate would affect the underground tunnels constructed across the non-uniform subsidence area, and cause abnormal displacement or foundation failure. In addition, a series of geologically related environmental issues may occur during underground development, e.g., groundwater contamination, changes of groundwater flow field, or the liquefaction of sandy powder soils. In this paper, the authors investigated the influence of geological conditions on underground utilization and relevant environmental issues that arise with constructions, and elucidated the monitoring objects, index and methods for underground space development, with the purpose of contributing to geological security insurance for underground space utilization.

关 键 词：城市地质 地下空间 地质安全监测 对象 方法 体系 

分 类 号：P64[天文地球—地质矿产勘探] P66[天文地球—地质学]