| 摘要: |
| 【目的】探讨不利围岩条件下调压井的应力变形特性。【方法】以摩洛哥某水电站调压井工程为例，运用大型有限元软件，建立了调压井应力变形分析的三维有限元模型，通过仿真计算获得了施工期与运行期调压井围岩及衬砌结构应力变形的分布与变化规律。【结果】在不利围岩条件下，施工开挖过程中围岩径向位移均指向井内，随着下层岩体的开挖，上层岩体的径向位移不断增大；沿高程方向，径向位移自上而下呈递减趋势，衬砌之前围岩变形基本稳定；运行期衬砌结构内、外侧环向正应力的分布规律沿高程方向基本一致，除调压井底部阻抗孔口处及调压井顶部外，内、外侧环向正应力均以拉应力为主，且自上而下大体呈递增趋势，内、外侧环向拉应力最大值均发生在调压井底部与阻抗孔口衔接处；施工期和运行期井周围岩的径向最大压应力及环向最大压应力均远小于围岩体的设计抗压强度，因此施工期井周围岩不会产生塑性破坏。【结论】在不利围岩条件下，调压井施工应采用自上而下分层开挖的方法，并及时喷锚和延迟一级衬砌；在调压井底部需采取加大衬砌混凝土标号、加设钢板内衬等增加强度的措施。 |
| 关键词: 水工结构 复杂围岩条件 调压井 应力变形 |
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| 基金项目:陕西省教育厅科学研究计划项目（03JK098） |
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| Finite element simulation analysis of surge tank’s stress and deformation under the conditions of an adverse rock |
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| Abstract: |
| 【Objective】Morocco hydroelectric station’s surge tank was taken as an example to investigate the behavior of surge tank’s stress and deformation under the conditions of an adverse rock.【Method】The 3-D finite element model by the large-scle finite element software was built.Distribution and change law were gaind after analyzing the strain deformation of surge tank’s surrounding and lining structure in construction period and operation period.【Result】Calculation indicates that when the surge tank is under the conditions of an adverse rock,the radial of surrounding rock will generate inward deformation with the excavation of the lower rock,radial displacement of the upper rock becomes larger;along with the elevation direction,radial displacement has a decreasing trend from top to down;the deformation of surrounding rock is stable before lining;in operation period,the distribution of ring’s normal stress of lining structure’s inside and outside along the elevation direction is consistent,except for surge tank’s orifices department and the top of surge tank,ring’s normal stress of inside and outside are mainly tensile stress and generally show an increasing trend;the maximum of ring’s normal stress of inside and outside occurrs at the bottom of surge tank connection with the orifice;in construction and operation period,the radial maximum compressive stress and the maximum compressive stress of ring of rock nearby surge tank are both much less than the intensity of anti-compression designed,Thereby,in the construction period,the rock does not produce plastic damage.【Conclusion】Under adverse geological condition surge tank,gushes an anchor in time and defers the one-level lining step;at the bottom of surge tank,it is necessary to increase the grade of concrete lining,steel plates’ inner lining and so on. |
| Key words: hydro-structure complex geological condition surge tank project stress and deformation |
