不同山体坡度初始地应力特点及对地下工程影响

在高山峡谷地区修建地下工程，山体坡度不同时会对初始地应力有十分重要的影响。通过数值分析研究了当山坡坡角分别为30°、45°和60° 时，在重力场条件下山体中在垂直向和水平向典型剖面中初始地应力分布的特点。经比较后认为，若在山体中取其直接埋深算出的垂直向地应力数值与实际值相差很大。山坡越陡，差值越大。随后，又在45°的山体中设定开挖2个不同位置的洞室，并采用了节理岩体的损伤-断裂模型做数值分析，比较二者的稳定性状况。结果发现，其围岩的损伤度十分不对称，而且离坡面（或坡脚）越近，则破损区越严重。并提出了相应的结论和建议

Initial geostress field characters in mountain with different slopes and its influence on underground projects

When the construction of underground projects in alpine and gorge region is being conducted, different mountain slopes will have important effects on initial geostress distribution. In this paper, the initial geostress distribution of mountain at vertical and horizontal typical profiles were studied in the gravity field by numerical analysis, with conditions of slopes being 30°, 45° and 60°, respectively. After the comparison, it can be known that the calculated values of the vertical geostress which were obtained from direct depth of the mountains varied from the actual values greatly. The steeper the slope is, the greater the differences are. Then two caverns at different positions were set to excavation in the mountain, with slope of 45°in the computation models and the damage - fracture model of joint rock was adopted to analyze the rock stability for the two conditions. The results show that the damage degree of surrounding rock is very asymmetric; and the more close to the slope surface (or slope toe), then the more serious the damage degree is. Finally, the corresponding conclusions and recommendations are proposed.