松动荷载引起的公路隧道衬砌损伤演化特征及套拱加固的计算方法

项目名称： 松动荷载引起的公路隧道衬砌损伤演化特征及套拱加固的计算方法

项目编号： No.51478342

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑科学

项目作者： 刘学增

作者单位： 同济大学

项目金额： 85万元

中文摘要： 由于围岩劣化或地层扰动等因素导致作用在隧道上松动荷载增加，引起隧道不同程度的损伤，导致承载力下降。本课题拟针对松动荷载作用模式，采用室内模型试验、数值模拟、理论分析等手段，研究隧道衬砌与套拱补强结构的受力变形、裂缝扩展特征及破坏模式，揭示隧道衬砌开裂损伤演化规律，建立不同损伤状态下衬砌承载力的三维评价模型和基于梁-弹簧单元的简易计算模型，并反演梁单元刚度等效系数与裂缝弹簧单元参数；凝练基于损伤特征的健康度评价指标，量化其与承载力的对应关系。揭示二次受力模式下套拱补强结构的损伤机理，建立不同损伤状态下套拱补强结构承载力的评价模型；分析套拱补强结构承载力的关键影响因素，并提出原衬砌结构不同损伤状态下的截面承载力折减系数，建立不同形式套拱加固的设计计算方法，为松动荷载下隧道衬砌套拱补强提供科学依据。

中文关键词： 公路隧道；松动荷载；衬砌损伤；套拱加固；承载力评价

英文摘要： The tunnel will be damaged inordinately and the bearing capacity for lining will decline when loose pressure increases because of the surrounding rock degradation and strata disturbance. This project aims at studying the load and deformation of lining and inner lining reinforced structure, characteristics of cracks growth and its failure mechanism. Directing at the effect mode of loose pressure and adopting comprehensive methods of model tests, numerical simulation and theoretical analysis, research of the project is conducted to study the attenuation law of lining crack, establish three-dimensional evaluation model of lining capacity under different state of damage and invert equivalent coefficient beam element stiffness and spring element parameter of crack to concise the criteria of health diagnose based on damage characteristics and quantize its relationship with lining capacity. This project uncovers the damage mechanism of inner lining reinforcement under secondary load, establishes evaluation mode of the inner lining reinforcement structure's capacity, analyzes the key factors of inner lining reinforcement structure's capacity and presents section capacity's reduction coefficient of different damage state of the original lining structure, establishes the calculation method for inner lining reinforcement of different forms, provides theoretical supports for the design of inner lining reinforcement under loose pressure.

英文关键词： highway tunnel;loose pressure;lining crack;inner lining reforcement;capacity analysis