【作者】 龚建平；

【导师】 漆泰岳；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 进行隧道结构和支护设计时,首先必须确定隧道结构所承受的荷载(围岩压力)。当前对完整岩体和松散岩体中围岩压力都做了深入研究,并形成了相关理论能较好的解决隧道荷载问题。但对于裂隙介质中隧道荷载(围岩压力)的研究较少,严格上讲,完整岩体和松散岩体在自然界中是很少的,绝大多数是裂隙岩体,而裂隙岩体中结构面的性质特征却是决定围岩压力性状和隧道稳定性的重要原因。因此,本论文从岩体结构力学的角度出发,引入岩体结构的理论和概念,介绍了结构面和结构体的特征及其分类,并以裂隙岩体(主要是一组节理形成的层状岩体和多组节理形成的破碎岩体)为研究对象,运用较适合研究裂隙介质的离散单元法及其软件UDEC作为研究工具。首先从力学的角度分析在裂隙岩体(一组和多组节理)中开挖隧道洞室时围岩二次应力的分布特点和无支护条件下隧道的稳定性;接着探讨了一组节理(主要是顺层偏压岩体)形成的地质偏压岩体中开挖洞室后的围岩压力的分布特征,并重点分析了该条件下的围岩压力的分布特征与岩体结构面参数的敏感性关系,进而获得结构面参数对洞室稳定性与隧道偏压之间的关系,并通过项目例证;最后又探讨了多组结构面形成的破碎岩体中的围岩压力分布特征与结构面参数的敏感性之间的关系,以及隧道的稳定性研究,并把数值模拟结果与围岩压力的理论计算值进行对比分析,指出了裂隙围岩中围岩压力理论计算方法的各自适用情况与不足,并尝试提出了修正建议。本文通过数值分析,对裂隙岩体的围岩压力的分布规律以及隧道的稳定性做了探索性的研究,为类似隧道工程提供了一定的参考意见。更多还原

【Abstract】 In the process of designing tunnel structure and tunnel support, rock pressure ability must be defined firstly, which is applied to tunnel structure. Presently, rock pressure in complete rock mass and loosening rock mass has been researched profoundly and thoroughly; and the correlative theories being used to solve the tunnel-load problem have been formed. However, there is still a lack of research on rock pressure in fractured rock mass. Strictly speaking, it is rare to see the complete rock mass and loosening rock mass in nature, but fractured rock mass is much more common. And the nature as well as the character of structural plane in fractured rock mass is the major reasons determining the property of rock pressure and stability of tunnel.In this thesis, the theory and conception of rock mass structure have been introduced firstly in the respective of rock mass’s structural mechanics. Afterwards, the character and classification of structure plane as well as structure body are presented. Fractured rock mass, especially layered rock mass formed by volume joint and breaking rock mass formed by multi-volume joints, is regarded as principal subject, which is then investigated by Distinct Element Method and its software UDEC, the tools adapted to research discrete mediator. As to this investigation, the steps are divided into several steps as follows: firstly, under the condition of excavating tunnel in fractured rock mass, the distribution characters of Second stress and stability of tunnel with no support are studied; Secondly, the distribution of rock pressure ceased by excavation in the uneven pressure rock mass formed by volume joint, has been analyzed. And parameter sensitivity analysis of structural plane which cease the distribution of rock pressure also has been studied as an emphasis. Based on those two analyses, the relationship between the parameter of structural plane and the stability and uneven pressure of tunnel are obtained, verified by an item as well. At last, the discussion is made about the relationship between the parameter of structural plane and the distribution characters of rock pressure in cracking rock mass formed by multi-volume joints. Based on the comparison between the numerical modeling results and rock pressure calculation, the proposals are made to point out the theoretical arithmetic methods of the tunnel rock pressure and stability in fractured rock mass.In this thesis, the exploratory research on distribution regularities of rock pressure and stability of tunnel in fractured rock mass has been done through numerical modeling. At the same time, some reference suggestions have been offered for analogous tunnel construction.更多还原