裂损衬砌网-锚与板-锚加固结构力学特性试验  

Experimental Investigation on the Mechanical Performance of Retrofitted Cracked Linings with Mesh-bolts and Plate-bolts

作　　者：卢锋[1,2] 李聘聘 郑余朝 仇文革[1] LU Feng;LI Pin-pin;ZHENG Yu-chao;QIU Wen-ge(Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;School of Emergency Management,Xihua University,Chengdu 610039,Sichuan,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]西华大学应急管理学院,四川成都610039

出　　处：《中国公路学报》2022年第5期128-139,共12页China Journal of Highway and Transport

基　　金：国家重点研发计划项目(2017YFC0806000);国家自然科学基金项目(51991395,U1434206,51678497,52078431)。

摘　　要：为探明裂损衬砌维修加固后的力学性能,对裂损衬砌新型网-锚、板-锚轻型快速微创组合加固结构的全过程力学特性进行了研究。通过自主研制的卧式偏心加载装置,对网-锚、板-锚加固裂损衬砌后形成的组合结构进行大偏心受压反复加卸载试验,揭示了钢筋混凝土和素混凝土裂损衬砌加固组合结构的全过程荷载-挠度关系、破坏模式、裂缝发展规律及网/板片应变演化过程。研究结果表明:对于钢筋混凝土衬砌,未加固、网-锚加固和板-锚加固结构5次反复加卸载后峰值承载力相比首次峰值承载力分别降低了28.9%、25%和16.7%,网-锚加固和板-锚加固后结构的主裂缝总开展量相比未加固时分别减小了74.3%和61.4%,总挠度分别增加了25.5%和25.54%,裂损衬砌结构的裂缝宽度发展得以有效抑制,峰后韧性显著提高,剩余承载能力得到了更充分的发挥;对于素混凝土衬砌,网-锚加固和板-锚加固后最大峰后荷载相比首次峰值点分别增加了30.8%和6.7%,峰后总位移比峰前分别增加了1040.6%和413.0%,受拉侧主裂缝总开展相比开裂时的裂缝宽度分别增加约11.78倍和11.81倍,素混凝土衬砌由开裂后“一裂即坏”的脆性破坏转化为延性破坏,峰后韧性大幅增加;网-锚加固后结构掉渣风险显著降低且无掉块现象出现,板-锚加固后无掉渣、掉块现象;短锚无拔出迹象,仅个别短锚出现轻微弯曲变形;板-锚组合加固结构的峰后韧性要优于网-锚组合加固结构。The mechanical characteristics of a cracked lining retrofitted with mesh-bolts and plate-bolts were investigated to reveal the mechanical performance of cracked linings after reinforcement.Through a horizontal eccentric loading setup,a large-bias pressure repeated loading test was conducted on the retrofitted cracked lining.The load-deflection relationship,failure mode,crack development law,strain evolution process of the reinforcement,and plain cracked lining retrofitted with a mesh grid/corrugated steel plate were examined.The results showed that the first peak load capacity of the reinforced concrete structure compared to that of the unreinforced,mesh-bolts reinforcement,and plate-bolts reinforcement decreased by 28.9%,25.5%,and 16.7%,respectively.In addition,the crack width decreased by 74.3%and 61.4%and deflection increased by 25.5%and 25.54%after the mesh-bolts and plate-bolts reinforcements,respectively.The width of the cracked lining was effectively restrained.The post-peak resilience of the reinforced concrete was improved,and the residual bearing capacity of the structure could be completely utilized.Compared to the first peak point,the maximum post-peak load of the plain concrete structure with mesh-bolts-and plate-bolts reinforcements increased by 30.8%and 6.7%,respectively.Compared to the pre-peak displacement,the total post-peak displacement increased by 1040.6%and 413.0%,respectively.Additionally,the main crack width of the lining at the tensile side after retrofitting increased by approximately 11.78 and 11.81 times,respectively.The plain concrete lining changed from brittle to ductile failure.The post-peak resilience of the plain concrete lining was improved significantly.The risk of slag falling was significantly reduced,no blocks fell after the mesh-bolts reinforcement,and no slag or blocks fell after the plate-bolts reinforcement.Short bolts were not pulled out during the tests,and a few short bolts were slightly bent.The post-peak resilience of the cracked lining with the plate-bolts reinforc

关 键 词：隧道工程 维修加固 反复加卸载 裂损衬砌 峰后韧性 

分 类 号：U457.3[建筑科学—桥梁与隧道工程]