摘要
新型隧道支护体系采用钢架、连接筋、钢筋网及喷射混凝土组合的方式作为支护手段,及时进行围岩加固,这其中型钢钢架与格栅钢架有增强支护能力,有效加固围岩的作用,但型钢和格栅喷射混凝土初期支护结构的力学性能对比,目前仍没有相关试验研究。基于此问题,按照初支二衬联拱隧道新型支护形式,设置了型钢和格栅喷射混凝土结构进行试验,除此之外,为优化型钢喷混初支结构,试验改变了纵向连接筋的连接形式,通过室内加载试验,得到结论如下:(1)采用插入式的纵向连接筋连接,更能够优化型钢喷混初支结构,提高结构的整体刚度和承载力水平,但主要影响在加载后期;(2)在受荷相同时,型钢比格栅刚度大,提升承载力的效果更好,但其与混凝土的粘结力差。
The new tunnel support system adopts the combination of steel frame,splice bar,bar-mat reinforcement and sprayed concrete as the supporting means to timely strengthen the surrounding rock.The steel frame and the grid steel frame have the ability to enhance the support and effectively consolidate the surrounding rock.However,there has been no relevant experimental research on the comparison of the mechanical properties of the initial structure of the section steel and the grid sprayed concrete.In view of the problem,this paper tests the steel and grid shotcrete structures according to the new support form of the second lining combination arch tunnel of initial structure.In addition,in order to optimize the initial shotcrete structure with section steel,the connection form of the longitudinal connecting ribs is changed.The indoor loading test shows that.(1)The use of the plug-in longitudinal connecting rib connection can optimize the initial structure of section steel shotcrete and improve the overall stiffness and bearing capacity of the structure,but the main influence is in the late loading stage;(2)Under the same load,the rigidity of the section steel is larger than that of the grid,resulting in higher bearing capacity,but poorer concrete adhesion.
作者
刘军
常舒
杨志男
韩旭
LIU Jun;CHANG Shu;YANG Zhinan;HAN Xu(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)
出处
《铁道标准设计》
北大核心
2021年第2期116-122,共7页
Railway Standard Design
基金
北京市自然基金-北京市教委联合资助重点项目(KZ201810016021)。
关键词
隧道
初期支护
型钢
格栅
力学性能
室内加载试验
tunnel
initial support
section steel
grid
mechanical properties
indoor loading test
