膨胀岩隧道缓冲层复合支护体系让压机理  

Yield Stress Mechanism of Composite Support System at Swelling Rock Tunnel Buffer Layer

作　　者：刘刚[1] 王皓 许崇帮[1] 缪圆冰[3] 龚建伍[4] LIU Gang;WANG Hao;XU Chong-bang;MIAO Yuan-bing;GONG Jian-wu(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;Xixian Urban Construction,Xi’an,Shaanxi 710000,China;College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350002,China;School of Urban Construction,Wuhan University of Science and Technology,Hubei,Wuhan 430081,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]陕西西咸新区城建投资集团有限公司,陕西西安710000 [3]福州大学土木工程学院,福建福州350002 [4]武汉科技大学城市建设学院,湖北武汉430081

出　　处：《公路交通科技》2024年第8期181-188,共8页Journal of Highway and Transportation Research and Development

基　　金：交通运输部公路科学研究院交通强国试点项目(QG2021-1-3-3)。

摘　　要：为构建缓冲层复合支护体系理论模型,分析缓冲层复合支护体系让压机理,弥补当前缓冲层让压机理的局限性。利用弹性力学知识,以单层厚壁圆筒模型为基础构建3层厚壁圆筒模型,推导出缓冲层复合支护体系中支护结构受力与外荷载之间函数关系,并用数值模拟的方法验证缓冲层复合支护结构受力解析解的正确性。基于此理论模型,分析了有无缓冲层复合支护体系中二衬和初支的受力特点,总结出缓冲层让压机理:在含有缓冲层的复合支护体系中,缓冲层材料被压缩,初支能够发生更大的向内变形量,进而吸收外部荷载作用,减小二衬的受力,从而整个结构能够实现让压效果,即缓冲层复合支护通过缓冲层压缩实现让压。通过改变缓冲层厚度对让压机理进行分析。结果表明:当缓冲层厚度为5 cm时,初支的形变量增加了1.34 cm,传递到二衬上的作用力也相应减小了71.6%;当缓冲层厚度增加至10 cm时,二衬的受力也进一步减小,对二衬结构更为有利。在让压支护体系中,随着缓冲层被压缩,初支也会发生更大的变形,初支内部应力也会增大,尤其是环向应力,即缓冲层的让压对初支受力是不利的,对二衬受力是有利的。因此,在复合让压支护体系中,当外部作用力一定时,对支护体系中缓冲层的设计要同时考虑初支和二衬的应力,即缓冲层的厚度存在一个最优值。To build the theoretical model of buffer layer composite support system,the yield stress mechanism of buffer layer composite support system was analyzed to make up for the limitations of current buffer layer yield stress mechanism.The three-layer thick-wall cylinder model was constructed based on the single-layer thick-wall cylinder model with elasticity knowledge.The functional relation between the support structure stress and the external load in buffer-layer composite support system was deduced.The correctness of analytical solution of stress on the buffer-layer composite support structure was verified by using numerical simulation.Based on this theoretical model,the stress characteristics of secondary lining and the primary support in composite support system with or without buffer layer were analyzed.The yield stress mechanism of buffer layer was summarized.In the composite support system with buffer layer,the buffer layer material was compressed.The initial support would undergo greater inward deformation,thereby absorbing the external load,and reducing the secondary lining stress.Therefore the entire structure would achieve the compression effect.In other words,the composite support of buffer layer realized the compression through the buffer layer yield stress.By changing the thickness of buffer layer,the yield stress mechanism was analyzed.The result indicates that when the buffer layer thickness is 5 cm,the deformation of initial support increases by 1.34 cm,and the force transferred to the secondary lining is reduced by 71.6%.When the buffer layer thickness increases to 10 cm,the secondary lining force is further reduced,which is more favorable to the secondary lining structure.In the yield support system,when the buffer layer is compressed,the internal stress of initial support also increases.In particular,the circumferential stress(i.e.,the yield stress of buffer layer)is disadvantageous to the initial support,and advantageous to the secondary lining stress.Therefore,in the composite yield support sys

关 键 词：隧道工程 让压机理 厚壁圆筒模型 缓冲层 膨胀岩 

分 类 号：U451[建筑科学—桥梁与隧道工程]