塌陷土洞的地面安全警戒距离研究  

Study on the ground safety warning distance of sink hole

作　　者：刘晓明[1] 张旺林[1] 吴从义 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《自然灾害学报》2015年第1期158-163,共6页Journal of Natural Disasters

基　　金：国家自然科学基金资助项目(50808076))

摘　　要：土洞塌陷后如何确定地表的安全警戒距离是实践中亟待解决的问题,但现有研究成果很少。采用数值计算方法,考虑塌陷后土洞的空间效应,按轴对称模式进行建模,然后提出了分析塌陷土洞内壁临界稳定坡角和地表安全警戒距离的方法。通过对既有塌陷土洞案例的计算,初步验证了该方法的有效性。然后采用该方法研究了土洞内壁临界稳定坡角随土洞半径和洞深变化的规律。在此基础上,计算得到了典型塌陷土洞的地面安全警戒距离分布情况。分析表明,塌陷发生在一般路基压实土范围内时,地表安全警戒距离最大值可取2.5 m;对于一般正常固结土,地表安全警戒距离最大值可取5.0 m。该成果可供土洞抢险时参考。How to determine the safety warning distance on the ground surface after sink hole occurs is of great urgency,meanwhile little effort was conducted on this problem. The analysis methods on determining the critical stable angle of the interior slope of sink hole and the safety warning distance on ground surface were proposed by employing numerical method. The sink holes were modeled as axisymmetric problem using numerical method which could consider the 3 dimension effect of the sink hole. After the methods were validated primarily by conducting calculation on case histories of sink holes,the variation of critical stable angle of the interior slope of sink hole with radium and depth of sink hole were analyzed by employing the methods. Based on the analysis results the distribution range of safety guard on ground surface distance of typical sink hole was calculated. Results show that when sink hole occurs in common embankment area the maximum safety warning distance could be 2. 5 m while in common consolidated soil area that distance could be 5. 0 m. Hopefully the analysis results could be used as references for wrecking work of sink hole.

关 键 词：土洞 安全距离 轴对称 数值分析 临界稳定坡角 

分 类 号：TU43[建筑科学—岩土工程]