摘要
为合理确定大溶腔小跨度公路隧道溶洞跨越方案,利用工程类比法,结合工程特点拟采用空腔回填、隧拱+梁板的跨越方案,通过三维数值分析软件模拟隧拱+梁板跨越施工过程。在既有溶洞稳定的状态下,隧道衬砌施作后,纵梁中心位置竖向最大沉降量为0.76 mm,溶洞中心隧道拱脚位置衬砌最大沉降量为0.58 mm,纵梁及隧道衬砌以溶洞中心为界向两侧竖向沉降逐渐减小,隧道衬砌水平收敛量最大为0.07 mm;纵梁两侧支点位置存在压应力集中,最大值为4.21 MPa,纵梁中心位置存在拉应力集中,最大拉应力为0.43 MPa,隧道衬砌结构应力小于纵梁应力,且均小于结构材料强度。依据变形及应力计算结果,在大溶腔小跨度且隧道衬砌位于溶腔上部的情况下,采用空腔回填、隧拱+梁板跨越方案最优。
In order to reasonably determine the large cavity and small span highway tunnel crossing scheme,using the engineering analogy method,combined with the engineering characteristics,the crossing scheme of cavity backfill,tunnel arch+beam plate was adopted and a tunnel arch+beam plate crossing construction process was established through the three-dimensional numerical analysis software.Under the condition that the existing cave is stable,and after the tunnel lining is applied,the maximum vertical settlement at the center of the longitudinal beam is 0.76 mm,and the maximum vertical settlement at the arch foot of the central tunnel is 0.58 mm.The vertical settlement of the longitudinal beam and the tunnel lining gradually decreases from the center of the cave to both sides,and the maximum horizontal convergence of the tunnel lining is 0.07 mm.Compressive stress concentration exists at the fulcrums on both sides of the longitudinal beam,with a maximum value of 4.21 MPa,and tensile stress concentration exists at the center of the longitudinal beam,with a maximum value of 0.43 MPa.The structural stress of the tunnel lining is smaller than that of the longitudinal beam,and both are smaller than the strength of structural materials.According to the calculation results of deformation and stress,when the tunnel lining is located in the upper part of the cavity and the cavity is large and the span is small,the best solution is cavity backfilling and tunnel arch+beam slab crossing.
作者
朱丹晖
聂浩
ZHU Danhui;NIE Hao(Ji'nan Design Branch of China Railway Engineering Design and Consulting Group Co.,Ltd.,Ji'nan 250022,China)
出处
《铁道勘察》
2023年第6期144-150,162,共8页
Railway Investigation and Surveying
关键词
岩溶
公路隧道
大溶腔
小跨度
空腔回填
隧道拱墙
梁板结构
karst
highway tunnel
large karst cavity
small span
cavity backfill
tunnel arch
beam slab
