昆仑山隧道漏水灾害的链式机制及断链新措施

STUDY ON CHAIN-STYLED MECHANISM AND NEW-TYPED CHAIN-CUTTING METHOD FOR WATER LEAKAGE DISASTER IN KUNLUN MOUNTAIN TUNNEL

根据现场监测数据,阐述昆仑山隧道在各个阶段的漏水灾害情况;运用灾害链式规律的观点,揭示昆仑山隧道出现漏水灾害的链式机制;根据灾害链的断链原理和隧道漏水灾害的链式机制,按照保护冻土的原则,提出一种抛石断链新措施,并进行抛石断链措施的设计,同时指出该断链新措施在设计和施工过程中的的关键技术问题;根据传热学和渗流力学的基本理论,建立冻土渗流场和温度场耦合问题的三维数学模型,应用Galerkin法导出有限元计算公式,编制有限元分析程序。运用该数学模型和有限元分析程序,对昆仑山隧道DK977+578～DK977+682浅埋段在采取和不采取抛石断链新措施两种条件下的渗流场和温度场耦合问题进行三维非线性分析。分析结果表明:防治昆仑山隧道漏水灾害采取抛石断链新措施是可行的,可为寒区隧道漏水灾害的抛石断链新措施的应用和设计提供理论依据,为寒区隧道出现的漏水灾害提供新的分析思路和新的治理措施。

The disasters of water leakage of the Kunlun Mountain Tunnel in Qinghai—Tibet Railway are introduced by the time step based on the measured in-situ data.From the viewpoint of the chain-styled rule,the chain-styled mechanisms of the water leakage disaster in Kunlun Mountain Tunnel are proposed.According to the principle of the chain breakage and the chain-styled mechanisms of the water leakage disaster,a new-typed method of the chain breakage is presented based on the principle of protecting the frozen soil layer from thawing using the ripped-stone method.The design of the ripped-stone is considered;and the key techniques during designing and constructing the ripped-stone are put forward.According to the basic theories of heat transfer and seepage,considering the coupled effects of seepage field and temperature field,a three-dimensional computational model of the coupled issues is given.The finite element formulae of this problem are obtained by Galerkin′s method;and the computer programme of the finite element is written.Using this model and the computer program,the three-dimensional nonlinear analysis for the coupled issues of seepage field and temperature field of the flat segment DK977+578—DK977+682 in Kunlun Mountain Tunnel on Qinghai—Tibet Railway is made under the two conditions of using and not using the ripped-stone method.The results show that it is feasible that the ripped-stone method is used for breaking the chain of the water leakage hazard in the permafrost tunnels.So,the theoretic foundation of the ripped-stone method is provided for its application and design in cold region tunnels.And the new analysis method,the new prevention and reinforcement measures are proposed for the water leakage disaster in cold region tunnels.