青岛R3线地铁隧道稳定性分析及衬砌优化研究
发布时间：2018-08-20 07:36
【摘要】：青岛市是我国国家沿海重要的中心城市和滨海度假旅游城市,国际性港口城市。伴随着青岛市的飞速发展,需要建设大量的城市地下铁道以缓解日益紧张的交通状况,青岛地区的"上软下硬"地层对于地铁隧道修建理论和技术提出了新的挑战,鉴于青岛地区特有的地层,以往的的理论和其他城市工程经验并不能对青岛地铁的修建提供有效的建议,因此有必要针对青岛地铁隧道稳定性和支护设计进行专门的研究。本文以青岛R3线为工程背景,基于R3线某区间沿线地质情况及现有隧道结构形式,利用强度折减法计算洞室围岩有支护和无支护情况下的稳定性,并基于安全系数对现有初期支护形式进行了优化,本文主要完成了以下工作:1.简要地介绍了岩土工程数值计算中常用的M-C本构、D-P本构及MCC本构模型,介绍了强度折减法基本原理、失稳判据及其地下工程中安全系数的定义。2.采用有限元软件ABAQUS中内置的D-P本构模型,利用强度折减法对青岛R3线某区间内Ⅲ级至Ⅵ级围岩下1m至20m埋深下的洞室稳定性进行了计算分析,得出了该区间内开挖浅埋隧道时围岩稳定性的空间分布:随着上覆岩层厚度的增加,围岩的稳定性呈现出先增加后减少的过程,还得出了上软下硬地层中围岩失稳而产生破坏形式及塑性区分布。3.采用有限元软件ABAQUS中内置的D-P本构模型,利用强度折减法计算了现有初期支护形式在Ⅲ级至Ⅵ级围岩在对围岩稳定性的加强作用,基于围岩安全系数对现有区间地铁隧道初期支护形式进行了评价,认为目前采用的初期支护过强,具有可优化的空间。提出了优化后的初期支护形式,并对优化后的初期支护形式计算了围岩安全系数,保证了优化设计的安全性。最后基于地层-结构法计算了优化初期支护后二次衬砌的安全系数,计算结果表明:优化设计不仅可以保持围岩具有足够的稳定性,还能使隧道支护结构在使用年限内具有足够的安全裕度保证正常使用。
[Abstract]:Qingdao is an important coastal city and an international port city. With the rapid development of Qingdao, it is necessary to build a large number of urban underground railways to ease the increasingly tense traffic situation. The "upper soft and hard" strata in Qingdao area pose new challenges to the theory and technology of subway tunnel construction. In view of the unique strata in Qingdao area, previous theories and other urban engineering experiences can not provide effective suggestions for the construction of Qingdao subway, so it is necessary to study the stability and support design of Qingdao subway tunnel. Taking Qingdao R3 line as the engineering background, based on the geological conditions along a certain section of the R3 line and the existing tunnel structure, the stability of the surrounding rock of the cavern with or without support is calculated by using the strength reduction method. And based on the safety factor to optimize the existing initial support form, this paper mainly completed the following work: 1. This paper briefly introduces the M-C constitutive D-P constitutive model and MCC constitutive model commonly used in numerical calculation of geotechnical engineering, and introduces the basic principle of strength reduction method, the instability criterion and the definition of safety factor in underground engineering. By using the D-P constitutive model built in the finite element software ABAQUS, the stability of the cavern under the buried depth of 1m to 20m is calculated and analyzed by using the strength reduction method in a certain section of the R3 line in Qingdao. The spatial distribution of surrounding rock stability during excavation of shallow tunnel in this section is obtained. With the increase of overlying rock thickness, the stability of surrounding rock presents the process of first increasing and then decreasing. The failure form of surrounding rock and the distribution of plastic zone in the upper soft and hard strata are also obtained. By using the D-P constitutive model built in the finite element software ABAQUS and using the strength reduction method, the strengthening effect of the existing initial supporting forms on the stability of surrounding rock in grade 鈪，
本文编号：2192897
[Abstract]:Qingdao is an important coastal city and an international port city. With the rapid development of Qingdao, it is necessary to build a large number of urban underground railways to ease the increasingly tense traffic situation. The "upper soft and hard" strata in Qingdao area pose new challenges to the theory and technology of subway tunnel construction. In view of the unique strata in Qingdao area, previous theories and other urban engineering experiences can not provide effective suggestions for the construction of Qingdao subway, so it is necessary to study the stability and support design of Qingdao subway tunnel. Taking Qingdao R3 line as the engineering background, based on the geological conditions along a certain section of the R3 line and the existing tunnel structure, the stability of the surrounding rock of the cavern with or without support is calculated by using the strength reduction method. And based on the safety factor to optimize the existing initial support form, this paper mainly completed the following work: 1. This paper briefly introduces the M-C constitutive D-P constitutive model and MCC constitutive model commonly used in numerical calculation of geotechnical engineering, and introduces the basic principle of strength reduction method, the instability criterion and the definition of safety factor in underground engineering. By using the D-P constitutive model built in the finite element software ABAQUS, the stability of the cavern under the buried depth of 1m to 20m is calculated and analyzed by using the strength reduction method in a certain section of the R3 line in Qingdao. The spatial distribution of surrounding rock stability during excavation of shallow tunnel in this section is obtained. With the increase of overlying rock thickness, the stability of surrounding rock presents the process of first increasing and then decreasing. The failure form of surrounding rock and the distribution of plastic zone in the upper soft and hard strata are also obtained. By using the D-P constitutive model built in the finite element software ABAQUS and using the strength reduction method, the strengthening effect of the existing initial supporting forms on the stability of surrounding rock in grade 鈪，
本文编号：2192897
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