隧道初期支护钢拱架的应力分布规律研究

发布时间：2018-03-18 06:13

本文选题：隧道　切入点：钢拱架　出处：《铁道学报》2017年09期 　论文类型：期刊论文

【摘要】：隧道开挖时,由于地质条件的不确定性和复杂性,导致支护结构受力状态发生变化,因此掌握支护结构应力分布规律对于隧道工程安全施工具有十分重大的意义。以下穿渝湘高速公路的凤咀江铁路隧道为背景,利用数值模拟和实际监测研究不同围岩和不同拱架间距下隧道初期支护钢拱架的应力分布规律,研究表明:(1)Ⅴ级偏差围岩最大拱架间距取0.8m,Ⅴ级偏好围岩最大拱架间距可增大至1.0m;(2)从应力分布角度看,钢拱架内外侧应力大部分为拉应力,且钢拱架最大拉应力出现在拱脚处,最大压应力在拱顶处;(3)当围岩质量状况变差时,钢拱架应力和应力梯度会迅速增大,钢拱架受力不均匀性也会显著增加;(4)在Ⅴ级偏差围岩条件下,当增大拱架间距时,钢拱架应力会迅速增加,因此要严格控制好拱架间距。
[Abstract]:When the tunnel is excavated, because of the uncertainty and complexity of the geological conditions, the stress state of the supporting structure changes. Therefore, mastering the stress distribution law of supporting structure is of great significance for the safe construction of tunnel engineering. By using numerical simulation and actual monitoring, the stress distribution law of steel arch frame supporting in the initial stage of tunnel under different surrounding rock and different arch spacing is studied. The results show that the maximum arched space of grade V deviated surrounding rock is 0.8 m, and the maximum arch spacing of grade V preferred rock can be increased to 1.0 m ~ 2) from the stress distribution point of view, the internal and external side stress of steel arch is mostly tensile stress, and the maximum tensile stress of steel arch appears at the arch foot. When the mass of surrounding rock becomes worse, the stress and stress gradient of the steel arch will increase rapidly, and the inhomogeneity of the steel arch will increase significantly.) under the condition of V-grade deviation surrounding rock, when the arch spacing is increased, the stress and stress gradient of the steel arch will increase rapidly. The stress of steel arch will increase rapidly, so the spacing of arch should be strictly controlled.
【作者单位】：北京交通大学隧道及地下工程教育部工程研究中心;中铁十二局集团第三工程有限公司;
【基金】：国家自然科学基金(51178026) 企业资助“浅埋暗挖隧道穿越渣填土层及下穿高速公路关键控制技术研究”(KCL15055530)
【分类号】：U455.7

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