面板堆石坝面板力学模型及应力分析

Mechanical model and stress analysis of CFRD slabs

面板堆石坝面板裂缝问题一直是制约其发展的一个关键技术问题。相对于竣工期混凝土干缩和温度应力造成的早期细小裂缝而言,蓄水期坝体结构受力变形是造成面板裂缝的控制因素。根据蓄水期面板受力情况,将面板看作弹性地基(堆石体)上的梁,根据鲍幸涅斯克弹性理论求得堆石体对面板的法向抗力和切向抗力,由面板微元受力模型,应用材料力学推导出面板顺坡向应力和轴向挤压应力的表达式。算例表明,公式可以用于估算面板顺坡向最大应力和轴向最大挤压应力。最后分析了表达式中有关参数的变化对面板应力的影响。此研究对控制面板应力和变形、防止面板裂缝具有一定的参考价值。

The slab crack problem is a key technical issue that hinders the development of CFRD.Compared with the microscopic cracks caused by shrinkage and thermal stress in the time of dam completion,the deformation of dam structure due to impoundment is the controlling factors for crack of concrete slabs.According to the loading condition of the slab in the storage period,we considered the slab as a beam on elastic foundation,and deduced the normal and tangential resistance based on the theory of Boussinesq.J.The expression of slab stress along the slope and extrusion stress along dam axial were proposed based on loading model of slab micro-segment.It is shown that the expression can be used to estimate the maximum stress along the slope and the maximum extrusion stress along axis.The effects of relevant parameters to slab′s stress were analyzed.This study provides a good reference for establishing a more reasonable mechanical model of the slab and controlling the slab crack.