岩溶山区城市地下隧道工程地质灾害风险分析

Risk analysis of the geological hazards during urban tunnel construction in mountainous karst areas

岩溶山区城市地下隧道工程施工过程中存在大量不确定地质灾害风险因素,由于成本和工期等原因无法详细查明所有水文地质和工程地质灾害风险源,导致各种灾害事故频发。目前对于隧道工程灾害评价方法多依靠专家打分,受人为主观因素影响大,且部分评价指标难以量化。为解决上述问题,依托岩溶山区轨道交通工程—贵阳市轨道交通2号线一期工程,统计其26段区间隧道施工过程中灾害发生位置、类型,仅选取明显相关地质灾害风险因素作为评价因素,根据灾害类型和地质灾害风险因素的位置关系反演出灾害发生频率与地质灾害风险因素间的耦合关系,建立岩溶山区城市隧道工程风险灾害评价体系。评价结果表明灾害发生频率与评价体系分段结果吻合程度均在69%以上,评价体系能够较好预测灾害发生频率。

Construction of urban tunnel engineering in mountainous karst regions involves a plethora of uncertain geological risk factors.Due to cost and schedule constraints,hydrogeological and engineering geological risk sources cannot be identified in detail,leading to frequent disasters.Expert scoring,which is influenced by human subjectivity,is a common method for disaster evaluation in tunnel engineering,and some evaluation indicators are difficult to quantify.In order to address these issues,Guiyang rail transit line 2 Phase I project was selected as a case study to establish a risk disaster evaluation system for urban tunnel engineering in mountainous karst regions.The location and type of the disasters during construction were recorded for 26 running tunnels,and geological risk factors that were significantly correlated were selected as evaluation factors.The coupling relationship between the frequency of disaster occurrence and the geological risk factors was inverted,leading to the establishment of the risk disaster evaluation system of urban tunnel engineering in mountainous karst region.The evaluation results demonstrate that the degree of consistency between the frequency of disaster occurrence and the segmentation results of the evaluation system is more than 69%,indicating that the evaluation system is capable of predicting the frequency of disaster occurrence effectively.