考虑围岩膨胀特性的深埋圆形隧道弹塑性统一解  

Unified elasto-plastic solution for deep-buried circular tunnels considering the swelling characteristics of surrounding rock

作　　者：沈英男 徐永涛 SHEN Yingnan;XU Yongtao(Ningxia College of Construction,Yinchuan 750001,China;Zhongding Century Engineering Design Co.,Ltd.,Chengdu 610000,China)

机构地区：[1]宁夏建设职业技术学院,银川750001 [2]中鼎世纪工程设计有限公司,成都610000

出　　处：《北京交通大学学报》2024年第3期100-108,共9页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：山东省自然科学基金(ZR2017BEE020)。

摘　　要：针对隧道及地下工程中围岩吸水膨胀导致应力与位移场变化难以量化的问题,基于弹塑性与湿度应力场理论,采用统一强度理论与非关联流动法则,推导考虑中间主应力效应与围岩吸水膨胀特性的深埋圆形隧道弹塑性统一解.首先,结合考虑湿度变化的平衡方程与本构方程,获得围岩弹性状态下的应力与位移解;然后,提出围岩弹塑性状态的判定方法,并基于统一强度理论推导围岩塑性状态下的解析解;最后,通过算例对比分析验证本文所推统一解的准确性,并进一步探究中间主应力、湿度膨胀系数以及含水率变化对围岩应力场与塑性区半径的影响规律,研究结果表明:本文与已有文献所求塑性区半径偏差仅为0.136%,验证了本文所推统一解的合理性;在所提供支护抗力相同的前提下,考虑围岩膨胀特性计算所得塑性区半径扩大,弹-塑性界面的环向应力增加,考虑围岩膨胀特性所得塑性区半径与环向应力是不考虑膨胀特性的1.06倍;当统一强度理论参数从0.0增加到1.0时,弹-塑性界面的环向应力增幅为6.6%,塑性区半径降幅为13.9%,隧道洞壁位移降幅为16.0%;当湿度膨胀系数分别取值0.00与0.10时,由于湿度膨胀系数影响引起的弹-塑性界面环向应力与塑性区半径增量分别达17.98%与27.4%;当最大含水率从0.00增加到0.06时,弹-塑性界面的环向应力增幅为16.9%,塑性区半径增幅为23.1%,隧道洞壁位移增幅为100%.研究成果可为膨胀岩隧道结构设计提供理论依据.Addressing the challenge of quantifying variations in stress and displacement fields induced by surrounding rock swelling due to water absorption in tunnels and underground engineering,this study develops a unified elastic-plastic solution for deep-buried circular tunnels.The solution considers the intermediate principal stress effect and swelling characteristics of the surrounding rock,employing elastic-plastic theory and humidity stress field theory.Firstly,stress and displacement solutions under elastic conditions of the surrounding rock are derived by integrating equilibrium and constitutive equations considering humidity changes.Secondly,a method for determining the elastic-plastic state of surrounding rock is proposed,and an analytical solution under plastic conditions is then obtained based on the unified strength theory and non-correlated flow rule.Finally,the accuracy of the proposed unified solution is verified by the example comparison and analysis.Further,the study investigates the influence of intermediate principal stress,humidity swelling coefficient,and water content changes on surrounding rock stress fields and plastic zone radius.Results indicate that comparative analysis with literature demonstrates a negligible 0.136%deviation in the plastic zone radius,validating the rationale of the proposed unified solution.Incorporating swelling characteristics increases the plastic zone radius and hoop stress at the elastic-plastic interface by 1.06 times under equivalent support resistance conditions.Increasing the unified strength theoretical parameter from 0.0 to 1.0 results in a 6.6%increase in hoop stress,a 13.9%decrease in plastic zone radius,and a 16.0%reduction in tunnel wall displacement.Moreover,varying the humidity swelling coefficient from 0.0 to 0.1 leads to 17.98%and 27.4%increases in hoop stress and plastic zone radius,respectively.Similarly,increasing the maximum water content from 0.0 to 0.06 results in a 16.9%increase in hoop stress,a 23.1%expansion in plastic zone radius,and a 100%incre

关 键 词：深埋隧道 膨胀应力 湿度场 统一强度理论 弹塑性解 

分 类 号：TU451.2[建筑科学—岩土工程]