砂卵石地层非对称连拱隧道结构受力模型试验研究

发布时间：2018-11-23 19:54

【摘要】：针对砂卵石地层特性配制了围岩相似材料,利用自主研发的大型平面模型试验台架,对不同荷载条件下非对称连拱隧道的受力特性进行了深入研究,重点分析了衬砌外表面压力和结构内力的分布及变化特点,总结了隧道裂缝的发展规律和结构破坏过程。试验结果表明:非对称连拱隧道大洞衬砌外表面压力显著大于小洞,但两者分布规律相似,最大值均位于拱顶,其次为内侧拱肩,外侧拱腰处最小;左右洞室受力不对称导致隧道中墙存在明显偏压;注浆加固圈可以有效降低衬砌外表面压力,改善结构受力条件,提高结构稳定性。结构内力在加载过程中呈现出复杂变化,在裂缝产生之前,基本保持线性增长;首条裂缝出现后,结构内力重新分布,但总体上仍具有一定的承载能力;当裂缝充分发展,特别是当拱部出现裂缝后结构承载能力大幅下降。衬砌结构首先于内侧拱脚处出现纵向裂缝,随着荷载的增加,裂缝数量和宽度也逐渐增加且主要分布在靠近中墙一侧。
[Abstract]:According to the characteristics of sand and gravel strata, the similar materials of surrounding rock are prepared, and the mechanical characteristics of asymmetric multi-arch tunnel under different load conditions are deeply studied by using the self-developed large-scale plane model test-bed. The distribution and variation characteristics of the outer surface pressure and the internal force of the lining are analyzed emphatically, and the development law of the tunnel crack and the structural failure process are summarized. The test results show that the external surface pressure of the large tunnel lining of asymmetric multi-arch tunnel is significantly higher than that of the small tunnel, but the distribution of both is similar, the maximum value is located at the arch top, the second is the inner arch shoulder, and the minimum is at the outer arch waist. The asymmetric force of the left and right caverns leads to the obvious bias of the middle wall of the tunnel, and the grouting ring can effectively reduce the external surface pressure of the lining, improve the stress condition of the structure and enhance the stability of the structure. The internal forces of the structure show complex changes during the loading process, and keep linear growth before the cracks occur, and the internal forces of the structure are redistributed after the first crack appears, but it still has a certain bearing capacity on the whole. When the cracks are fully developed, especially when cracks appear in the arch, the bearing capacity of the structure decreases significantly. The longitudinal cracks appear in the inner arch at first. With the increase of the load the number and width of the cracks increase gradually and are mainly distributed near the side of the middle wall.
【作者单位】：北京交通大学城市地下工程教育部重点实验室;北京交通大学土木建筑工程学院;
【基金】：国家自然科学基金面上项目(51378002) 国家科技支撑计划项目课题(2012BAJ01B03)
【分类号】：U451

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