中文摘要：

基于混凝土材料细观层次的研究，对钢筋混凝土梁开裂面的力学性能进行了分析和数值模拟。引人开裂面法向和切向的应力一应变关系假定，模拟了裂缝出现后开裂面由于骨料咬合和微裂缝嵌入的互制作用；采用弹性地基梁理论分析了钢筋销栓作用对开裂面应力传递的影响；在此基础上，基于开裂区应变分解思想，采用等效连续模型将开裂面和裂缝间混凝土统一，将裂缝的影响隐含在等效的本构模型及相关参数中，并给出了开裂单元的屈服准则、加卸载准则及增量型有限元中本构矩阵的数值计算方法。典型构件的试验结果验证了本文数值模型的合理性和有效性。

英文摘要：

For basin-scale water quality hydro-dynamic models, interval inflow is a very important input. In real-time operation of pollution events, uncertainty of the interval inflow within operating horizon will di- rectly affect the results of simulated model. In this paper, the uncertainty of interval inflow is represented by statistical distributions, based on which synthetic inflows are generated for Monte Carlo simulation, us- ing the water quality hydrodynamic model as simulation tool. This method is applied to a case of the Huai- he River basin, and the results show that it can provide pollution accident probability forecast to water en- vironmental managers, and thus provide better support for real-time operation decisions.