高面板堆石坝面板应力规律分析及改善应力状态的对策

本文分析了面板应力分布及其产生的原因，采用接触力学分析方法模拟混凝土面板和堆石体之间的接触关系，应用假设应变单元，消除因弯曲变形造成的面板单元剪切自锁问题，从而减少面板挠度和应力数值计算误差。在面板温度仿真计算方面，针对不同的入仓温度采用不同的混凝土绝热温升曲线。变形、温度和湿度等方面数值计算显示，弯曲应力场、遭遇寒潮后的温度应力场以及湿度应力场分布趋势相同，它们叠加后，易使面板发生裂缝。最后对某在建高面板堆石坝，提出采用增大面板与堆石体的高程差、推迟Ⅱ期面板浇筑和喷涂聚氨酯保温板等工程措施，以改善面板应力状态。计算结果表明，面板拉应力可降低一个数量级，由原来的1.0MPa量级下降到0.1MPa量级。

Stress analysis of concrete slab in high CFRD and measures for improving the stress state

The contact analytic mechanics is applied to simulate the contact behavior between the concrete slabs and crushed rock. The effect of shear locking in bending is eliminated by the assumption of strain formulation. Therefore the simulation of the deformation and stress status in concrete slabs is more accurate. In the calculation of temperature simulation, different temperature rising process curves of concrete are adopted according to the corresponding placing temperature. The numerical analysis of a high CFRD in China is used as an example for demonstration. The measures for improving the stress distribution of slabs including enlarging the elevation difference between slabs and rockfill as well as postponing the placing of the second phase slabs and heat preservation layers are adopted. The calculation result shows that these measures are very effective in reducing the tensile stress of the slabs.