贵州某隧道工程地质条件分析研究

Analysis and research on engineering geological conditions of a tunnel in Guizhou province

该隧道地处贵州高原西部,场区属溶蚀—侵蚀地貌单元。主要采用工程地质调绘、钻探等综合勘察手段进行,基本查明隧道所处场地的工程地质条件、水文地质特征、岩土体工程地质特征,对场地稳定性做出评价,场区不良地质为岩溶、危岩体及堆积体。根据地质调绘、岩样试验等成果分析,测区野外岩土体主要物理量力学试验成果及岩体完整性系数显示,施工中易发生大规模突发性涌水、涌沙、突泥等危害,应做好防排水措施设计,避免隧道内积水,保证排水通畅。分段确定围岩级别及力学指标,围岩产状平缓,顶板岩体受爆破震动易塌落,应加强围岩支护加固措施;边仰坡开挖临空易发生垮塌,应加强坡体加固防护措施,确保安全。详勘阶段加强场区工程地质勘察,进一步查明场区工程地质条件,为初步设计提供工程地质资料。

The tunnel is located in the western part of Guizhou plateau and belongs to the dissolution-erosion geomorphic unit.This work is mainly carried out by engineering geological mapping,drilling and other comprehensive survey methods.We intend to find out the engineering geological conditions of the tunnel,hydrogeological feature and engineering geological characteristics of rock soil mass,evaluate the stability of the site and the poor geology in the field are karst,dangerous rock mass and accumulation body.According to the analysis of geological mapping,the testing results of rock samples,the main physical and mechanical data and rock mass integrity coefficient of the field rock mass in the survey area,large scale sudden water,sand,mud and other hazards are easy to occur in the construction stage,which deserves to do a good job in the design of waterproof and drainage measures,to avoid water in the tunnel and ensure the smooth drainage.This work determines the grade of surrounding rock and mechanical indexes.And the formation of the surrounding rock is gentle,and the roof rock mass is easy to collapse due to the blasting vibration.Side slope excavation is prone to collapse,so the slope should be strengthened to ensure safety.so as to provide engineering geological data for the preliminary design.