黄土隧道台阶法施工效应及技术参数研究

发布时间：2018-01-12 02:02

本文关键词：黄土隧道台阶法施工效应及技术参数研究　出处：《石家庄铁道大学》2015年硕士论文　论文类型：学位论文

【摘要】：台阶法因为在隧道开挖过程中对围岩的扰动次数比较少,有利于围岩稳定,有利于机械化施工,适应性强,工法易于转变,施工组织和安全控制难度小应该在未来一段时间内仍是铁路隧道的主要施工方法。而目前关于黄土隧道台阶法施工的规范还不够全面和详细,本文针对此通过对宝兰隧道资料的数据统计分析以及对不同施工技术参数如:台阶长度、高度、封闭距离工况条件进行模拟计算,并对中下台阶开挖工序进行优化以及对辅助措施工工况进行了模拟,得到一些结论,并给出施工技术参数建议值。(1)对黄土物理力学参数及台阶法技术参数进行了统计分析,得到了各参数的统计值以及之间的关系。(2)通过对台阶长度、台阶高度工况模拟结果的对比分析得出了不同含水率条件下台阶长度、台阶高度对隧道开挖的影响规律并结合数据统计给出不同含水率条件下台阶长度、台阶高度的参考值。(3)通过对预留核心土开挖核心土不同尺寸的计算结果进行对比分析,得出核心土能够很好的控制掌子面的变形,且核心土尺寸越大,效果越明显。给出建议值为核心土高为2 m左右,上下底为其所在高度洞宽的1/3~1/2,长度为3~4m左右。(4)通过对三种开挖工序的对比分析得出中槽先行左右交错开挖要优于左右侧交错开挖,而左右交错开挖要优于中槽先行开挖,且给出了三种工序的施工技术参数参考值。中槽先行两侧交错开挖工序的施工技术参数建议值:上台阶核心土长度为5m左右,中台阶间隔距离为3~4 m,下台阶间隔4~6 m。左右交错开挖工序的施工技术参数建议值:上台阶核心土长度为5 m左右,中台阶左右两侧的间隔距离为2~4 m,下台阶左右两侧间隔距离为2 m左右。中槽先行开挖工序的施工技术参数建议值:上台阶核心土长度为5 m左右;中台阶先行距离为2~4 m,下台阶先行距离为4~6 m。(5)超前支护能很好地控制拱顶下沉,超前支护与临时仰拱均能有效控制周边收敛以及初支最大最小应力及围岩最大塑性应变。给出辅助措施的施工技术参数:超前支护的长度为4~5 m。
[Abstract]:Step method is beneficial to the stability of surrounding rock, mechanized construction, strong adaptability and easy to change because of the less disturbance times of surrounding rock in the excavation process of tunnel. Construction organization and safety control should be the main construction method of railway tunnel for some time in the future, but the current construction criterion of loess tunnel step method is not comprehensive and detailed enough. In this paper, through the statistical analysis of the data of Baolan Tunnel and the simulation of different construction technical parameters such as: step length, height, closed distance operating conditions. The excavation procedure of middle and lower steps is optimized and the working conditions of auxiliary measures are simulated, and some conclusions are obtained. The suggested value of construction technical parameters is given. (1) the physical and mechanical parameters of loess and the technical parameters of step method are statistically analyzed, and the statistical values of each parameter and the relationship between them are obtained. By comparing and analyzing the simulation results of bench height, the influence of step length and step height on tunnel excavation under different water content conditions is obtained, and the step length under different water content conditions is given in combination with data statistics. The reference value of step height. 3) through the comparison and analysis of the calculation results of different sizes of core soil excavated by reserved core soil, it is concluded that the core soil can control the deformation of palm surface very well, and the larger the size of core soil is. The more obvious the effect is, the suggested value is that the core soil height is about 2 m, and the upper and lower bottom is 1 / 3 / 1 / 2 of the width of the hole in which the core soil is located. Through the comparative analysis of the three excavation procedures, it is concluded that the left and right interleaving excavation is better than the left and right interleaving excavation, and the left and right interleaving excavation is better than the middle slot first excavation. The construction technical parameters of three kinds of working procedures are given. The construction technical parameters of the staggered excavation on both sides of the middle groove are suggested: the length of the core soil is about 5 m and the distance between the middle steps is 3 m. The construction technical parameters of the staggered excavation procedure are suggested: the core soil length of the upper step is about 5 m, and the distance between the left and right sides of the middle step is 2 ~ 4 m. The distance between the left and right sides of the lower step is about 2 m. The suggested value of the construction technical parameters of the first excavation procedure of the middle groove is: the length of the core soil of the upper step is about 5 m; The first distance of middle step is 2m, and the distance of lower step is 4m.) the advance support can control the sinking of the vault well. Both advanced support and temporary inverted arch can effectively control peripheral convergence, maximum and minimum stress of initial support and maximum plastic strain of surrounding rock. The construction technical parameters of auxiliary measures are given: the length of advance support is 4m.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4

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