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| A Stability Analysis Method ofthe Overhanging Crag with Longitudinal Cracks |
| CUI Hong - huan1，LIU Jian - kun1，ZHANG Li - qun2，HAN Hui - xun3 |
| (1. Beijing Jiaotong University， Beijing 100044， China; 2. Hebei Institute of Architecture and Civil Engineering， Zhangjiakou，Hebei 075000, China; 3. The Third Railway Survey and Design Institute Group Corporation，Tianjin 300142, China) |
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Abstract Research purposes: There are a number of boulders exposed on the surface of steep slopes along the railway line，when the high - speed railway is constructed in mountain areas where volcanic and sedimentary rocks are widely distributed. Some overhanging rocks may develop longitudinal cracks because of erosion， differential weathering and other factors. These dangerous rock mass with different sizes and shapes will bring about the great security risk to the construction and operation of high - speed railways. Unfortunately， there was no logical and rational method to meet actual conditions of the overhanging crag with longitudinal cracks. So the method of calculating the safety factor should be studied timely for stability of crags to make technical support for reinforcement and prevention of unstable rocks along the railway in the mountains. Research conclusions:(1) The new model which is based on overhanging portion of the rock body beside longitudinal crack indicates that the ultimate tensile strength of rock is assumed to be the determination basis for analysis of its stability. ( 2 ) A new analysis software is developed on the basis of the stability analysis model which is established in the plane coordinate system for a crag with longitudinal cracks. ( 3 " The research is applied for stability of quartz sandstone crags by searching the most dangerous potential fracture planes at the exit of Benxi tunnel in the Passenger Line from Shenyang to Dandong, and the minimum safety factor of overhanging crags is obtained. (4) The research result can provide a valuable engineering basis for design of slope at Benxi tunnel exit.
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Received: 26 August 2015
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2016, Vol. 33 
