岩石风化程度对土岩双元基坑变形的影响  

Influence of the Degree of Rock Weathering on the Deformation of Foundation Excavated in Soil-rock Dual Stratigraphic Texture

作　　者：宋娜 赵红艳 李登科 齐银萍 张晋元 段抗[2] SONG Na;ZHAO Hong-yan;LI Deng-ke;QI Yin-ping;ZHANG Jin-yuan;DUAN Kang(Shandong Zhengyuan Resources Geological Exploration Co.,Ltd.,Jinan 250001,China;School of Civil Engineering,Shandong University,Jinan 250001,China)

机构地区：[1]山东正元地质资源勘查有限责任公司,济南250061 [2]山东大学土建与水利学院,济南250061

出　　处：《科学技术与工程》2023年第26期11317-11326,共10页Science Technology and Engineering

基　　金：国家自然科学基金(51909138)。

摘　　要：土岩双元基坑是指开挖深度范围内,上部为土层、下部为岩层的基坑。由于下部岩层的力学性质与上部土层差异较大,因此传统纯土体的一元结构基坑设计理论与经验对该类基坑的适用性较差。利用FLAC3D有限差分软件,建立不同岩石风化程度的土岩组合基坑计算模型,研究不同岩石风化情况下土岩双元基坑的变形规律,并用连续-离散耦合模型模拟土+破碎岩石基坑失稳过程。结果表明:若岩层完整,最大水平位移出现在土层中,岩层中水平位移很小;若岩层为破碎状,最大水平位移有可能出现在岩层中;岩层中的黏土夹层也可能是基坑最大变形出现的部位;破碎岩石内部的破坏是同土层同步发育的,最终二者一起发生整体滑移破坏。了解基坑的变形规律,有助于针对性地采取加固措施,对破坏区域的细观研究为基坑支护设计提供了依据。Foundation excavated in soil-rock dual stratigraphic texture refers to the foundation pit in which the upper part is the soil layer and the lower part is the rock layer within the depth of excavation.Since the mechanical properties of the rock layers differs significantly from those of the soil layers,the traditional theories based on a single layer and experiences gained from pure soil foundation are no longer applicable.A numerical model of soil-rock combination foundation pit with different degrees of rock weathering is established using the finite difference software FLAC3D.The influences of rock weathering conditions on the deformation characteristics of foundation in soil-rock dual stratigraphic texture were investigated.A continuum-discrete coupling model was adopted to simulate the failure process of foundation composed of soil and fractured rock.Simulation results show that:if the rock formation is intact,the maximum horizontal displacement occurs in the soil layer,and the horizontal displacement in the rock layer is very small.If the rock formation is fractured,the maximum horizontal displacement may appear in the rock layer.Moreover,the clay interlayer in the rock formation may also be the site where the maximum deformation occurs.The failure within the fractured rock develops simultaneously with the soil layer,ultimately leading to the sliding of the whole slope.A proper understanding of the deformation characteristics of the foundation pit and the failure process may shed light on the selection and design of reinforcement and support measures.

关 键 词：土岩双元基坑 岩石风化程度 基坑变形 有限差分模拟 连续-离散耦合 

分 类 号：TU457[建筑科学—岩土工程]