隧道洞口边仰坡稳定性的上限分析

发布时间：2018-04-10 03:00

本文选题：隧道边坡　切入点：稳定性分析　出处：《中南大学》2014年硕士论文

【摘要】：摘要：随着我国经济的迅速发展及基础设施投入的加大,在工程建设中出现了越来越多的隧道工程。隧道洞口边仰坡的稳定性关系到整个隧道施工的顺利进行。另外,若隧道洞口所处地段地质条件较差,极易出现滑坡问题。如何保证隧道洞口段工程施工的安全和质量,便成为研究热点。针对隧道洞口边仰坡所处的地质条件及实际工程情况,本文采用极限分析上限原理对隧道洞口边仰坡的稳定性进行分析,主要包括以下几个方面的内容： (1)基于极限分析上限原理,建立了隧道洞口边仰坡的对数螺旋线破坏机构,对其稳定性进行分析。首次计算了隧道洞口边仰坡的上限计算公式,计算了其外部重力做功功率以及内部能量耗散功率方程,将隧道洞口边仰坡临界高度的求解转化为非线性规划的数学问题。将计算结果与已有的极限平衡法结果进行比较,可知两者的计算结果相差不大,进而验证了本文方法的有效性。 (2)考虑地震力荷载、孔隙水压力作用的影响,并结合强度折减技术,计算了复杂情况下隧道洞口边仰坡的安全系数。通过参数分析,得出地震力及孔隙水压力对隧道洞口边仰坡稳定性的影响。 (3)针对非均质土体中应用上限定理的困难,利用滑动面离散技术,通过关键点的坐标生成速度间断面,研究了非均质土的隧道洞口边仰坡的稳定性问题。与传统解析方法的比较说明,当破坏机构的主要参数相同时,离散方法求得的功率与解析方法求得功率相近,验证了离散方法的有效性。 (4)根据蒙华煤运通道九条岭隧道边仰坡工程及湘西大干溪I号隧道洞口边仰坡滑坡工程,利用本文提出的稳定分析方法,对实际隧道边仰坡的安全系数及临界高度进行了计算。结果表明,本文提出的上限分析方法对于隧道边仰坡稳定性分析是可靠和有效的。本文共有图35幅,表5个,参考文献97篇。
[Abstract]:Absrtact: with the rapid development of economy and the increase of infrastructure investment, more and more tunnel projects appear in the engineering construction.The stability of the elevation slope at the entrance of the tunnel is related to the smooth construction of the tunnel.In addition, if the geological condition of the tunnel entrance is poor, landslide is easy to occur.How to ensure the safety and quality of the tunnel entrance construction has become a research hotspot.In view of the geological conditions and the actual engineering conditions of the slope at the tunnel entrance, this paper analyzes the stability of the slope of the tunnel entrance by using the upper limit theory of limit analysis, which mainly includes the following aspects:1) based on the upper limit principle of limit analysis, the logarithmic helix failure mechanism of tunnel entrance slope is established and its stability is analyzed.For the first time, the upper limit formula of tunnel entrance slope is calculated, the external gravity work power and internal energy dissipation power equation are calculated, and the solution of critical height of tunnel entrance slope is transformed into a mathematical problem of nonlinear programming.Comparing the calculated results with the results of the existing limit equilibrium method, it can be seen that there is little difference between the two results, and the validity of the proposed method is verified.(2) considering the influence of seismic load and pore water pressure, and combining with strength reduction technique, the safety factor of tunnel entrance slope is calculated under complex conditions.Through parameter analysis, the influence of seismic force and pore water pressure on slope stability of tunnel entrance is obtained.In view of the difficulty of applying the upper bound theorem in heterogeneous soil, the stability of tunnel entrance slope in heterogeneous soil is studied by using slip surface discretization technique and velocity discontinuity surface generated by coordinates of key points.The comparison with the traditional analytical method shows that when the main parameters of the failure mechanism are the same, the power obtained by the discrete method is similar to the power obtained by the analytical method, which verifies the validity of the discrete method.4) according to the slope engineering of Jiujiaoling tunnel and the landslide project at the entrance of Daganxi No.1 tunnel in western Hunan, the safety factor and critical height of the actual tunnel slope are calculated by using the stability analysis method proposed in this paper.The results show that the upper bound analysis method proposed in this paper is reliable and effective for the stability analysis of tunnel slope.There are 35 figures, 5 tables and 97 references in this paper.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U453.1

【参考文献】