活性粉末混凝土棚洞板落石冲切损伤评估方法  

Assessment Method for Rock Impact and Punching Damage of Reactive Powder Concrete Tunnel Ceiling Slab

作　　者：苗守举 张川[2] 钟汉清 MIAO Shouju;ZHANG Chuan;ZHONG Hanqing(Jiangxi Provincial Communications Investment Group Co.Ltd Project Construction Management Company,Nanchang 330052,China;Southwest Jiaotong University,Chengdu 610031,China;East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]江西省交通投资集团有限责任公司项目建设管理公司,南昌330052 [2]西南交通大学,成都610031 [3]华东交通大学,成都330013

出　　处：《铁道建筑》2025年第1期127-135,共9页Railway Engineering

基　　金：江西省交通运输厅科技项目(2023H0018);国家自然科学基金青年科学基金(52208407)。

摘　　要：为了评估铺设砂垫层的钢筋混凝土(Reinforced Concrete,RC)棚洞顶板在落石冲击作用下的损伤度,提出了一种用于冲切力作用下棚洞顶板的损伤评估方法。设计了弧形试验板及90 cm厚的砂土层试验模型,开展了能量为50~250 kJ的9组冲击试验,通过高速摄影、动态数采系统采集试验数据,研究了试验板的冲击力响应特征。采用光滑粒子流体动力学-有限元法(SmoothedParticle Hydrodynamics-Finite Element Method,SPH-FEM)耦合方法建立了冲击试验动力有限元模型,拓展分析了模型的冲击动力响应特征。选取落石质量和冲击速度作为损伤评估主控变量,建立了基于冲切承载力的损伤评估指标,并划分损伤评估等级,通过仿真试算与拟合建立了损伤评估曲线图解方法,并分析了RC板参数、缓冲层厚度对板件损伤度的影响,对比分析了活性粉末混凝土(Reactive Powder Concrete,RPC)与普通混凝土板的抗冲击性能。研究结果表明:在相同的冲击能量下,落石质量越大,板件损伤程度更大;混凝土抗压强度对板件损伤度影响最大,钢筋屈服强度对板件损伤度影响最小。缓冲层厚度对板件损伤度影响显著,板件在60 cm缓冲层防护下的抗冲击性能相比于90 cm缓冲层下降20%~30%;RPC板具有良好的抗冲击性能,约为C40混凝土板的2~3倍。In order to assess the damage degree of reinforced concrete tunnel ceiling slabs with a sand cushion layer subjected to rockfall impacts,a method for damage assessment of concrete tunnel ceiling slabs under the punching force was proposed.An experimental model consisting of an arc-shaped testing slab and a 90 cm thick sand cushion layer was constructed.Nine groups of impact experiments with energies ranging from 50~250 kJ were conducted on an impact test platform.Test data were collected with a high-speed camera and a dynamic data acquisition system,and the force response characteristics of test slab were studied.The dynamic impact model was established using the software to analyze the impact dynamic response characteristics of the model based on the Smoothed Particle Hydrodynamics-Finite ElementMethod(SPH-FEM)coupled method.The mass and the velocity of rockfall were selected as the main control variables for damage assessment.Then the damage assessment index based on the punching bearing capacity was established and divided.The graphic method of the damage assessment curves was established by simulation,fitting and trial calculation.The influence of parameters of reinforced concrete slab and the thickness of the sand cushion layer on the damage assessment were analyzed.The impact resistances of Reactive Powder Concrete(RPC)and normal concrete slab were compared.The results show that,the larger mass rockfall may cause more damage to the concrete slab under the same impact energy.The compressive strength of concrete has the greatest influence on the damage degree of the slab,while the yield strength of steel has the least influence on the damage degree of the slab.A 90 cm thick sand cushion on a slab increases the impact resistance of the slab by 20%~30%compared with a 60 cm thick sand cushion layer.Moreover,it is found that the RPC concrete slab has good impact resistance,which is 2~3 times that of the C40 concrete slab.

关 键 词：铁路防灾 落石 模型试验 棚洞板 数值模拟 损伤评估 

分 类 号：U453.1[建筑科学—桥梁与隧道工程] TU528[交通运输工程—道路与铁道工程]