大方老城区地表建筑物变形机制研究

Discussion on the Deformation Mechanism of Surface Buildings Caused by Groundwater Dynamic Variation in the Old Town of Dafang County

本文通过对研究区地表裂缝、地下水位、深部位移的监测,结合大量的现场调查和试验综合分析,认为引发研究区域地表建筑开裂变形的主要因素不是斜坡蠕滑变形,而是地下水动态变化因素引起的。研究结果表明具体影响因素有两点:一是近年来工程活动加剧地下水位的变化速率和频率,使原来就存在的不均匀沉降现象变得更加剧烈,致该区土层产生颗粒结构变化、土体强度变化;二是发生开裂变形的房屋其基础均为浆砌石条形基础,且基础宽度和埋深多数没有达到规范要求的理论值。

Based on the monitoring of surface cracks,groundwater level and deep displacement in the study area,combined with a large number of field investigations and comprehensive analysis of tests,we concluded that the main factor causing surface building cracking and deformation in this area is not creeping deformation of slope,but groundwater dynamic variation.The research results show that there are two specific factors:firstly,in recent years,engineering activities have intensified the change rate and frequency of groundwater level,which makes the original existence of uneven sedimentation phenomenon more severe,resulting in the change of grain structure and soil strength of soil layer;secondly,the foundation of cracked and deformed buildings is slurry masonry strip-shaped base,and most of the foundation width and buried depth do not reach the theoretical value required by the code.