基于岩爆烈度预测的川藏铁路线路比选研究

拟建川藏铁路线路穿越区域地质条件复杂,隧道工程占比高、埋深大和岩体初始应力高,具备岩爆灾害发育的必要条件,岩爆地质灾害的分析预测对川藏铁路线路比选尤为重要。通过分析国内地下工程岩爆案例,再结合新建川藏铁路某段的实际情况分析岩爆影响因素,考虑指标的重要性、相关性和易获取性,选取岩石强度、地应力、地质构造和围岩级别4个指标,采用层次分析法(AHP)-专家打分法,建立隧道岩爆灾害烈度预测模型。通过对拟建川藏铁路某段的K、A和C三个比选方案的隧道岩爆灾害烈度进行预测,并通过统计分析获得C方案的岩爆灾害影响最小,为推荐选线方案。在新建川藏铁路某段的岩爆烈度预测实际应用表明,该模型能较为快速地进行岩爆烈度预测,在铁路前期选线阶段具有较好的适应性。

Route Selection of Sichuan-Tibet Railway Based on the Prediction of Rockburst Intensity

The regions crossed by the proposed Sichuan-Tibet railway line are complex in geology. As a result, the tunnel engineering with deep buried depth and high initial stress of rock mass covers high proportion of the whole construction, which are the necessary conditions for the development of rockburst disaster. Therefore, it is particularly important to conduct analysis and prediction of rockburst geological disaster in Sichuan-Tibet railway route selection. Based on the analysis of the rockburst in underground engineering cases and in combination with the actual situation of a certain section of the newly built Sichuan-Tibet Railway, this paper analyzes the influence factors of rockburst, takes into consideration the importance, relevance and accessibility of the index, selects four indexes of rock strength, ground stress, geological structure and surrounding rock level, and finally builds the intensity prediction model of tunnel rockburst disaster through the Analytic Hierarchy Process(AHP)-Expert Scoring method. Through predicting the tunnel rockburst disaster intensity of three alternative plans K, A and C in a certain section of the railway, and the statistic analysis as well, this paper concludes that plan C should be the recommendation due to its least influence of the rockburst disaster. The practical application of rockburst intensity prediction in a certain section of the railway shows that the model can predict more quickly the rockburst intensity and is well adaptable in the early stage of route selection.