吕小宁. 2018: 二元结构深路堑边坡多级开挖静动力效应研究. 工程地质学报, 26(s1): 37-42. DOI: 10.13544/j.cnki.jeg.2018060
    引用本文: 吕小宁. 2018: 二元结构深路堑边坡多级开挖静动力效应研究. 工程地质学报, 26(s1): 37-42. DOI: 10.13544/j.cnki.jeg.2018060
    LÜ Xiaoning. 2018: STUDY ON MULTI-STAGE EXCAVATION EFFECT OF DEEP CUTTING WITH DUALISTIC LAYER. JOURNAL OF ENGINEERING GEOLOGY, 26(s1): 37-42. DOI: 10.13544/j.cnki.jeg.2018060
    Citation: LÜ Xiaoning. 2018: STUDY ON MULTI-STAGE EXCAVATION EFFECT OF DEEP CUTTING WITH DUALISTIC LAYER. JOURNAL OF ENGINEERING GEOLOGY, 26(s1): 37-42. DOI: 10.13544/j.cnki.jeg.2018060

    二元结构深路堑边坡多级开挖静动力效应研究

    STUDY ON MULTI-STAGE EXCAVATION EFFECT OF DEEP CUTTING WITH DUALISTIC LAYER

    • 摘要: 某铁路深路堑超高边坡,最大开挖高度达130 m,上部砂岩和下部灰岩不整合接触呈二元结构,多工作面、多级爆破开挖对设计和施工提出了很大的挑战。本文采用有限元极限平衡法和动力有限元法,考虑边坡二元结构的特点和岩体结构面的影响因素,进行了边坡五级开挖支护的静动力模拟,获得了不同施工开挖过程下的边坡破坏模式和安全系数。结果表明:(1)自上而下逐级开挖逐级支护的深路堑边坡稳定性依次由全强风化砂岩、二元结构界面和灰岩最不利结构面控制,并且,随着开挖深度增加,地应力逐渐得到释放,剪应力场发生偏转,塑性区域变小;(2)爆破施工开挖引起的位移场随爆源距近似球形衰减,且在二元结构界面处呈放大态势。研究成果对于铁路深路堑的设计和施工有重要借鉴意义。

       

      Abstract: A railway deep cutting with the maximum excavation height of 120m gives great challenges to design and construction because of dualistic layer structure and multi-stage blasting excavation. In this paper, considering the characteristics of the dualistic layer of the slope and the structural plane of rock mass, the static and dynamic simulation of the five-stage excavation and support is carried out with both the finite element limit equilibrium method and the dynamic finite element method, thus the failure mode and factor of safety is obtained. The simulation results show that:(1)The stability of the deep cutting is gradually controlled by the fully weathered sandstone, the dualistic layer interface and the most unfavorable structural plane of the limestone along with top-down multi-stage excavation. And as the excavation increases, the ground stress is gradually released, the shear stress field is deflected, and the plastic zone becomes smaller. (2)The displacement field caused by blasting decays approximately spherically with the distance from the blast source and is amplified at the interface of the dualistic layer. The research results have important implications for the design and construction of the railway deep cutting.

       

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