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为了解立洲水电站调压井应力应变情况,采用三维弹塑性损伤有限元法计算了正常运行工况、检修工况时的调压井同一高程处、不同高程处的应力应变数值,发现正常运行工况时的应力应变幅度大于检修工况。同一高程处调压井周边最大主应力为压应力,最大主应力值基本相等,呈对称均匀分布状态;随着高程的降低,调压井上游侧的最大主应力呈增大趋势,且在高程2 025～2 125m处检修工况下的最大主应力大于正常运行工况。在正常运行工况时同一高程处调压室周边最小主应力为拉应力,在检修工况时井筒中下部为拉应力、上部则为压应力,最小主应力值基本相等,呈对称均匀分布状态;随着调压井高程的降低,调压井上游侧的最小主应力呈增大趋势,检修工况下的最小主应力变幅极小。阻抗板上部应力分布较为复杂。同一高程井筒周围各点水平向位移量、沉降量基本相同,随着高程的降低水平位移量、沉降量逐渐增大,但检修工况下的水平位移及沉降变幅很小。计算结果表明,调压井外水压力对调压井衬砌结构的应力、变形影响均小于内水压力作用工况,因此在进行调压井配筋设计时应将内水压力作用下的正常运行工况作为控制工况。
In order to understand the stress and strain of the surge shaft at Lizhou Hydropower Station, the three-dimensional elastic-plastic damage finite element method was used to calculate the stress and strain values at the same elevation and different elevation of the surge shaft under normal operation and maintenance conditions, and found that normal operation The stress and strain at working conditions are greater than the maintenance conditions. The maximum principal stress around the surge shaft at the same elevation is compressive stress, and the maximum principal stress values are basically the same, showing a symmetrical and uniform distribution. As the elevation decreases, the maximum principal stress at the upstream side of the surge shaft increases, The maximum principal stress under 2 025 ~ 2 125m overhaul condition is greater than normal operating condition. In the normal operation condition, the minimum principal stress around the surge chamber at the same height is tensile stress. During the maintenance condition, the middle and lower part of the well bore is tensile stress, while the upper part is the compressive stress. The minimum principal stress values are basically equal and symmetrical and evenly distributed ; With the elevation of the surge shaft decreasing, the minimum principal stress at the upstream side of the surge tank tends to increase, and the minimum principal stress in the condition of maintenance is very small. Impedance plate stress distribution is more complicated. The horizontal displacements and settlements of each point around the same elevation are basically the same. The horizontal displacements and settlements increase with elevation decreasing, but the horizontal displacements and settlement amplitudes under the condition of maintenance are small. The calculation results show that the external water pressure of the surge shaft has less influence on the stress and deformation of the surge shaft lining structure than that of the internal water pressure. Therefore, during the design of surge shaft reinforcement, the normal operation under the effect of internal water pressure Condition as a control condition.