Analysis On Rock Stability Of Tunnel & Countermeasures Under Typical Adverse Geological Conditions

With the construction of infrastructure in our country, the design of highway tunnel and the technology of construction have developed rapidly. There are more and more tunnel projects at home and domestic; the length of the tunnel becomes longer and longer; the span of tunnel construction becomes larger and larger; the depth of tunnel becomes deeper and deeper. Meanwhile, the geological conditions that encounter during tunnel engineering become more and more complex. As tunnel engineering is a kind of underground work, people cannot know accurately the conditions of engineering geology beforehand; only by existing means of tests can people gain the basic knowledge of geological information such as geological environment. Therefore, it brings about great blindness to the tunnel design and construction, and often results in unexpectable collapse, roof fall and water burst during the construction. Once an accident happens, its light consequences may include effecting construction, damaging construction equipments, increasing cost of engineering and losing state property. To be more serious, it may cause tremendous casualties. What's more, the handling job is difficult after the accident and produce severe lost to economy and construction period.This paper is based on the Chalinding Tunnel in Guang-Wu Highway, Guangdong Province. The tunnel has an extremely undesirable geologic phenomenon, such as karst and fault zone.In order to avoid or reduce accidents like collapse, offer technical guidance to undesirable geological phenomenon warning system and treatment plan, it is necessary to development the study of stability of tunnel surrounding rock and construction strategies. The following parts are mainly on:â‘ By analyzing the influence of undesirable phenomenon to the stability of construction, calculate the type and character of potential accident.â‘¡Based on the data analysis of soft ground bench method, optimize the length of bench and size of core soil. â‘¢By analysis of undesirable geological identification features from geological prediction (GPR,TSP),combining the index of deformation of surrounding rock, establish the warning system during the construction.â‘£To the warned and graded undesirable phenomenon, make a proper treatment plan.