喷射混凝土强度概率分布特征对公路隧道结构可靠度的影响研究  

Study on the Influence of Probability Distribution Characteristics of Shot-concrete Strength on the Structural Reliability of Highway Tunnels

作　　者：王安怀 刘小飞 林壮宏 周瑜 宋恒祥 Wang Anhuai;Liu Xiaofei;Lin Zhuanghong;Zhou Yu;Song Hengxiang(Guangdong Province Nan Yue Traffic Investment and Construction Co.,Ltd.,Guangzhou 510623,China;Renxin Expressway Management Office in Guangdong Province Nan Yue Traffic Investment and Construction Co.,Ltd.,Shaoguan 512638,China;Guangdong Hualu Transport Technology Co.,Ltd.,Guangzhou 510420,China;Guangdong Provincial Key Laboratory of Tunnel Safety Technology and Emergency Support Technology&Equipment,Guangzhou 510420,China)

机构地区：[1]广东省南粤交通投资建设有限公司,广东广州510623 [2]广东省南粤交通仁新高速公路管理处,广东韶关512638 [3]广东华路交通科技有限公司,广东广州510420 [4]广东省隧道工程安全与应急保障技术及装备企业重点实验室,广东广州510420

出　　处：《市政技术》2024年第12期190-196,共7页Journal of Municipal Technology

基　　金：广东省重点领域研发计划资助项目(2002B0101070001);广东省交通集团有限公司科技项目(JT2023YB20)。

摘　　要：喷射混凝土强度概率分布特征是隧道结构可靠度研究的基础问题,但一直缺乏足够的数据支撑,其对隧道结构可靠度的影响也未引起足够的重视。基于此,首先,对2个典型隧道的喷射混凝土进行取芯测试,并收集相关文献数据进行统计分析,得到喷射混凝土强度的概率分布特征;其次,推导了考虑喷射混凝土强度概率分布特征的隧道结构极限状态方程,计算得到在Ⅲ~Ⅴ级围岩及其支护条件下,喷射混凝土不确定性引起的可靠指标下降规律。结果表明:公路隧道喷射混凝土强度表现出较强的不确定性,变异系数最高达到0.381,其概率分布基本符合正态分布。围岩级别越低,喷射混凝土不确定性导致的可靠指标下降程度就越大,具体表现为:Ⅲ级围岩下降6%,Ⅳ级围岩下降43%,V级围岩下降67%。隧道结构可靠指标与喷射混凝土的强度均值成正相关,与喷射混凝土的强度标准差成负相关。因此,在隧道结构设计时,应根据喷射混凝土的不确定性适当提高设计冗余;而在隧道施工时,必须采取有效的措施降低喷射混凝土的不确定性。The probability distribution characteristics of shot-concrete strength are fundamental issues in the study of tunnel structural reliability,but there has been a lack of sufficient data support,and its impact on tunnel structural reliability has not received sufficient attention.Firstly,core testing was conducted on shot-concrete of two typical tunnels.The relevant literature data was collected for statistical analysis to obtain the probability distribution characteristics;Secondly,the limit state equation was derived.Under the conditions of Ⅲ~Ⅴ grade surrounding rock and its support,the decrease law of reliability indices caused by the uncertainty of sprayed concrete was calculated.The results show that the strength of sprayed concrete in highway tunnels exhibits strong uncertainty,with the maximum variation coefficient of 0.381,and its probability distribution basically follows a normal distribution.The lower the level of surrounding rock,the greater the decrease of reliability indicators caused by the uncertainty of shot-concrete,specifically manifested as 6%decrease of Level Ⅲ surrounding rock,43%decrease of Level Ⅳ surrounding rock,and 67%decrease of Level Ⅴ surrounding rock.The reliability index of tunnel structure is positively correlated with the average strength of shot-concrete and negatively correlated with the standard deviation of shotconcrete strength.Therefore,when the tunnel structures are designed,design redundancy should be appropriately increased based on the uncertainty of sprayed concrete;Effective measures must be taken to reduce the uncertainty of shot-concrete during tunnel construction.

关 键 词：喷射混凝土 不确定性 概率分布 可靠度 

分 类 号：U451[建筑科学—桥梁与隧道工程] TU455[交通运输工程—道路与铁道工程]