ISSN 1000-3665 CN 11-2202/P
    孟振江,彭建兵,李超,等. 耦合型地裂缝活动特征与成因机制模拟研究−以北京宋庄地裂缝为例[J]. 水文地质工程地质,2023,50(3): 138-148. DOI: 10.16030/j.cnki.issn.1000-3665.202210038
    引用本文: 孟振江,彭建兵,李超,等. 耦合型地裂缝活动特征与成因机制模拟研究−以北京宋庄地裂缝为例[J]. 水文地质工程地质,2023,50(3): 138-148. DOI: 10.16030/j.cnki.issn.1000-3665.202210038
    MENG Zhenjiang, PENG Jianbing, LI Chao, et al. A simulation study of the activity characteristics and genetic mechanism of coupled ground fissures: Exemplified by the Songzhuang ground fissure in Beijing[J]. Hydrogeology & Engineering Geology, 2023, 50(3): 138-148. DOI: 10.16030/j.cnki.issn.1000-3665.202210038
    Citation: MENG Zhenjiang, PENG Jianbing, LI Chao, et al. A simulation study of the activity characteristics and genetic mechanism of coupled ground fissures: Exemplified by the Songzhuang ground fissure in Beijing[J]. Hydrogeology & Engineering Geology, 2023, 50(3): 138-148. DOI: 10.16030/j.cnki.issn.1000-3665.202210038

    耦合型地裂缝活动特征与成因机制模拟研究以北京宋庄地裂缝为例

    A simulation study of the activity characteristics and genetic mechanism of coupled ground fissures: Exemplified by the Songzhuang ground fissure in Beijing

    • 摘要: 以北京通州区宋庄地裂缝为原型,研究以断裂活动和抽水为主要诱因的耦合型地裂缝的发育活动特征和成因机制,揭示了不同位错量和水位下降量引发的地层位移场和应力场的变化特征。通过实地踏勘,阐明了地裂缝造成的地表平面及地层剖面的破坏现象;运用有限差分法模拟研究了断层错动和抽水2种工况下的模型地层的变化响应过程,最后讨论了该类型地裂缝与各诱因之间的关系。结果表明:(1)该类型地裂缝具有三维活动等特点,一般造成浅表地层及墙体的水平张开量为0.3~1.2 cm,深部地层的垂直位错量随埋深而逐渐增大;(2)断裂活动引起的应力变化在裂缝发育区集中,并造成上盘地层出现明显的竖向位移,裂缝区地层出现较大的剪切牵引变形,且其两侧的竖向位移差异量最大;断层位错量的增加造成隐伏裂缝向上逐渐延伸扩展,并在上盘浅表层引发次级裂缝,致使地裂缝整体呈具有一定宽度的带状展布;(3)地下水位下降对地裂缝的竖向延伸和水平扩张均有加剧作用,裂缝两侧地表产生持续的沉降响应,并导致沉降漏斗中心成为地裂缝集中发育区,且该处的模型地层沉降量也最大,为10.2 cm,上盘地层的沉降范围宽度约38 m,下盘约16 m;(4)该类型地裂缝受断裂控制明显,但现阶段活动加剧主要为超采地下水所致。研究将对深入理解地裂缝成因机理、建立地层响应和断裂位错与地下水变化的定量联系,以及防灾减灾具有重要理论意义和实际应用价值。

       

      Abstract: The active characteristics and genetic mechanism of coupled ground fissures mainly induced by fault activities and pumping are studied, and the Songzhuang Town in Tongzhou District of Beijing is taken as the research archetype. The damage of surface planes and stratigraphic profiles caused by ground fissure activities are clarified through field investigation, and the variation characteristics of the displacement field and stress field of the strata caused by different dislocation amounts and groundwater level drop are revealed. The response processes of the model stratum under the two conditions of fault misalignment and groundwater extraction are simulated and studied respectively by using the finite difference method. Finally, the relationship between this type of ground fissure and the main inducing factors is discussed. The results show that (1) the ground fissure is characterized by three-dimensional activities, which causes the vertical tension of the shallow stratum and wall to be 0.3−1.2 cm, and the vertical dislocation of the deep stratum gradually increases with the burial depth. (2) Stress changes caused by fracture activities are concentrated in the ground fissure development area and lead to significant vertical displacements in the hanging wall, the stratum located in the ground fissure area has large shear and traction deformation, and the vertical displacement difference between the two sides is the largest. The gradual increase of fault dislocations causes the hidden fractures to extend upward, and cause secondary cracks on the shallow surface of the hanging wall, resulting in the overall distribution of ground fissures with a certain width. (3) The vertical extension and horizontal expansion of ground fissures are aggravated by the lowering of groundwater levels, and the surface on both sides of the crack produces continuous settlement response, making the center of the subsidence funnel become a concentrated development area of ground fissures, with the maximum settlement of 10.2 cm in the model stratum at the fissure in its central area, and the settlement range of about 38 m in the hanging wall and about 16 m in the foot wall. (4) This type of ground fissures is obviously controlled by faults, but the increased activity in this period is mainly due to groundwater over-exploitation. This work will be of great theoretical and practical significance to understand ground fissure mechanism, establish quantitative relationship between formation and fault with groundwater, and prevent and reduce disasters.

       

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