高铁隧道穿越巨型溶洞超厚回填体沉降模型试验研究  

`Test Study on Settlement Model of Ultra-Thick Backfill in High-Speed Railway Tunnel through Giant Karst Cave

作　　者：王军[1,2,3] 李鑫 郭毕钧[1,3] 丁光亚 刘同江[2] 孙亚飞 于明洋[5] WANG Jun;LI Xin;GUO Bijun;DING Guangya;LIU Tongjiang;SUN Yafei;YU Mingyang(School of Civil Engineering,Shandong Jianzhu University,Jinan Shandong 250101,China;Postdoctoral Workstation,China Railway 14th Bureau Group Corporation Limited,Jinan Shandong 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Ministry of Education,Shandong Jianzhu University,Jinan Shandong 250101,China;Institute of Architectural Engineering,Wenzhou University,Wenzhou Zhejiang 325035,China;Qianjiang-Zhangjiajie-Changde Project Department,China Railway 14th Bureau Group Construction Engineering Co.,Ltd.,Jinan Shandong 250101,China)

机构地区：[1]山东建筑大学土木工程学院,山东济南250101 [2]中铁十四局集团有限公司博士后工作站,山东济南250101 [3]山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室,山东济南250101 [4]温州大学建筑工程学院,浙江温州325035 [5]中铁十四局集团建筑工程有限公司黔张常项目部,山东济南250101

出　　处：《中国铁道科学》2022年第4期84-95,共12页China Railway Science

基　　金：国家自然科学基金资助项目(51704176);山东省博士后创新项目(202003080);山东省高等学校土木结构防灾减灾协同创新中心项目(XTP201923)。

摘　　要：依托渝厦高铁黔常段高山隧道高位穿越巨型溶洞回填处置工程,按照几何相似比1∶5设计基于时序加载方式的列车动荷载作用下超厚回填体沉降相似模型试验,探究不同厚度钢筋混凝土路基板的隔振性能,以及巨型溶洞超厚回填体的沉降规律,验证巨型溶洞回填处置方案的合理性。结果表明:随着路基板厚度的增加,隧道模型的仰拱表层附加沉降逐渐减小,回填砂层受到列车动荷载扰动逐渐减小,路基板的隔振性能逐渐增加;从回填砂层表层到深层,由列车动荷载引起的振动加速度峰值、动土压力值均显著降低,且动土压力的传播范围逐渐缩小;当路基板厚为0.6 m时,回填砂层浅部50 cm范围内的动荷载扰动沉降仅0.02 mm,相当于实际工程中回填洞砟层浅部2.5 m范围内沉降0.10 mm。隧道开通运营1年来,监测隧道结构整体沉降低于1 mm,且趋于稳定,由此可见:高山隧道巨型溶洞采用“洞砟回填+上部注浆”处置,并辅以3 m厚钢筋混凝土路基板隔振的设计方案,是合理可靠的。Based on the backfill treatment project of the high mountain tunnels passing through the giant karst cave at a high level on Qianjiang-Changde section of Chongqing-Xiamen HSR,a similar model test of the settlement of ultra-thick backfill under train dynamic load based on sequential loading method was designed according to the geometric similarity ratio of 1∶5,in order to study the vibration isolation performance of reinforced concrete road base plates with different levels of thicknesses and the settlement law of the ultra-thick backfill of giant karst caves.The rationality of the treatment scheme for the backfill of giant karst caves was verified.The results show that as the thickness of the road base plate increases,the additional settlement for the invert surface layer of the tunnel model gradually decreases.Along with the increasing thickness,the disturbance of backfill sand layer caused by the train dynamic load gradually decreases,and the vibration isolation performance of the road base plate gradually increases.From the surface to the deep layer of backfill sand layer,both the vibration acceleration peak and the dynamic earth pressure value caused by the train dynamic load significantly decrease,and the propagation range of the dynamic earth pressure is gradually reduced.When the road base plate is 0.6 m thick,the dynamic load disturbance settlement within 50 cm of the shallow part in backfill sand layer is only 0.02 mm,which is equivalent to the settlement of 0.10 mm within 2.5 m of the shallow part in the backfill tunnel ballast layer in practical engineering.Over the first year of the tunnel operation,the overall settlement of the tunnel structure is less than 1 mm and tends to be stable.Therefore,the design scheme of the giant karst cave in high mountain tunnels using“ballast backfill+upper grouting”treatment,supplemented by 3 m thick reinforced concrete road base plate vibration isolation is reasonable and reliable.

关 键 词：高铁隧道 巨型溶洞 超厚回填体 动荷载扰动沉降 列车动荷载 隔振 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]