基于蠕变损伤演化模型的深部高地应力隧道双层初期支护力学特性研究  

Research on mechanical properties of double primary support method of deep buried tunnel based on damage evolution rheological model

作　　者：马杲宇 何川[1] 陈子全[1] 马春驰[2] 杨文波[1] 赖孝辉 MA Gaoyu;HE Chuan;CHEN Ziquan;MA Chunchi;YANG Wenbo;LAI Xiaohui(Key Laboratory of Transportation Tunnel Engineering,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]西南交通大学交通隧道教育部重点实验室,四川成都610031 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《中南大学学报（自然科学版）》2021年第8期2897-2909,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52008351,51991394);国铁集团系统性重大课题(P2019G38-4)。

摘　　要：为了研究深部高地应力陡倾层状千枚岩隧道施工期支护结构的力学特性,构建考虑黏塑性偏应变增量的蠕变损伤演化模型。以成兰铁路茂县隧道为依托,根据现场实测的变形数据,反演得出符合工程实际的蠕变参数。分别对采用单层初期支护和双层初期支护的断面开展数值模拟。研究结果表明:高地应力陡倾层状岩体的最大围岩压力和变形出现在隧道的拱腰位置,当采用双层初期支护工法时,断面承受的围岩压力和隧道周边千枚岩的变形较小,且能在较短的时间内达到稳定状态。二次衬砌拱腰位置承受的弯矩较大而轴力较小,处于大偏压状态。采用双层初期支护工法能够显著降低截面内力,提高截面的安全系数。高地应力陡倾软岩隧道围岩的损伤主要集中在拱腰位置,当采用双层初期支护工法时,围岩内部损伤的最大值和损伤分布区域面积分别降低了47.1%和26.7%,有利于发挥围岩的自承能力,降低围岩的蠕变特性。To analyze the mechanical properties of the lining structure adopted inthetunnel buried in deep steep broken phyllite stratum under high geostress, a creep damage evolution model considering the increasement of viscoplastic deviation strain was established. According to Maoxian tunnel on Cheng—Lan rail way, thecreep parameters suitable for the engineering condition were acquired by back analysis based on the deformation data.The single primary support method and double primary support method were both simulated by numerical method.The results show that the maximum rock pressure and deformation occur at the haunch of the tunnel buried in steep broken soft rock under high geostress. When double primary support method is adopted, the values of rock pressure and deformation decrease and can reach a steady condition in a shorter time. The bending moment at the tunnel haunch is relatively large, while the axial force is small, which makes the section under the large eccentric compression condition. The internal force can be significantly reduced by using the double primary support method and the safety factor can be enhanced simultaneously. Damage in the surrounding rock of the tunnel buried in steep broken soft rock under high geostress mainly occurs at the tunnel haunch. The double primary support can reduce the maximum value and area of the damage by 47.1% and 26.7%, respectively. Therefore, the selfsupporting capacity of the broken phyllite is improved and the creep property of the rock is reduced.

关 键 词：深部岩体 蠕变效应 破碎千枚岩 双层初期支护 反演 损伤演化 

分 类 号：TU443[建筑科学—岩土工程]