隧道初期支护结构安全性评价荷载分配比例研究  

Study on Load Distribution Ratio for Safety Evaluation of Tunnel Initial Support Structure

作　　者：朱峰 ZHU Feng

机构地区：[1]四川安泰工程勘察设计有限公司,四川成都610000

出　　处：《内蒙古公路与运输》2024年第6期28-30,52,共4页Highways & Transportation in Inner Mongolia

基　　金：国家自然基金青年项目(52108385)。

摘　　要：隧道设计目前仍然以工程类比法为主,理论计算验证为辅,在初期支护钢拱架结构安全性评价过程中,《公路隧道设计细则》(JTG/T D70—2010)对弯矩分配的方式与实际结构受力情况稍有偏差,导致依据规范选取的衬砌支护参数在进行综合安全系数计算时,计算结果不满足规范要求。文章针对这一问题,依据材料变形协调一致原理对初期支护结构的弯矩分配方法进行优化,推导出钢拱架与喷射混凝土弯矩分担比例公式,按照公式计算出的弯矩分担比例与数值模拟方式计算出的钢拱架弯矩分担比例比较,结果基本吻合。工程实例验证结果显示,按照荷载分配比例计算的安全系数与数值模拟计算的安全系数结果相近且具有一定的包容性,优化后的弯矩分配方法具有推广价值。At present,the tunnel design is still mainly based on engineering analogy method,supplemented by theoretical calculation and verification.In the safety evaluation process of steel arch of initial support,the bending moment distribution method from Guidelines for Design of Highway Tunnel(JTG/T D70-2010)is slightly deviated from the actual structural stress condition.As a result,when calculate the comprehensive safety coefficient of initial support of which the parameters are selected according to the Specification,the calculation results do not meet the requirements of the Specification.In order to solve this problem,this paper optimizes the bending moment distribution method of the initial support structure according to the principle of material deformation coordination and consistency,and derives the bending moment distribution ratio formula of steel arch and shotcrete.The bending moment distribution ratio of the steel arch calculated by the formula is compared with the moment distribution ratio calculated by numerical simulation,and the results are basically consistent.It is verified by engineering examples that the safety factor calculated according to the load distribution ratio is similar to the safety factor calculated by numerical simulation and has certain inclusivity.The optimized bending moment distribution method has the value of popularization.

关 键 词：隧道 钢拱架 弯矩 分配比例 

分 类 号：U445[建筑科学—桥梁与隧道工程]