山岭隧道穿越冲沟段塌方风险预测与分析

Collapse risk forecast and analysis of crossmountainous tunnel constructionviagully sections

为建立特殊地质情况下的隧道施工穿越冲沟段塌方风险预测模型,统计分析了200例隧道塌方的原因,以京新高速旗下营隧道工程为背景,结合该隧道的工程地质特点,选取岩体结构类型、围岩条件、不良地质状况、开挖跨度、隧道埋深、结构偏压和管理水平7个风险影响因素,分别采用三角模糊判断矩阵法和统计分析得到各因素的主、客观因素权重,基于综合赋权法得到各因素的综合权重,据此建立隧道塌方风险模糊评估模型。应用该模型对依托工程进行塌方风险预测,结果能较好地反映工程实际情况。

The paper aims to introduce our forecasting and analysis model formountainous tunnel construction through collapse-prone gu-l ly sections. For this purpose, we have collected over 200 tunnel cave-collapsing cases in the tunnel construction both at home and abroad and made summary over their research experience based on the analysis of the statistical data available. And then, we have d-i vided 14 collapsing factors under special geological conditions into four major categories. Furthermore, we have taken Qixiaying Tunnel construction project of Beijing-Xinjiang Expressway as our case study samples with our research focus on investigating and exploring such influential factors, as the natural structure types of the rockmass, the scarcely-seen geological conditions of the rocks, the dissymmetrical pressure, etc. And, finally, we have established mathematical simulations over the relations among the above-said factors and the co-l lapse events. Moreover, we have gained Integrated Weights of all the influential factors based on Comprehensive Weight Method by using the triangular fuzzy judgment matrix and statistical analysis. Thus, it can be said that the fuzzy evaluation model of the tunnel collapsing hazards we have proposed is soundly based on the historical data and the dynamically regulated data from the evaluation indexes in close accordance with the actual situations. The actually done monitoring and measuring results indicate that our fuzzy evaluation model comes in conformitywith the actual collapsing liabilities. This shows that the model is valuable for forecasting the collapsing risks for tunne-l construction projects and can be used as a significant guide for the safety management of the tunnel construction.