胶凝砂砾石坝破坏机制及极限承载能力的模型试验理论与方法研究

AS a new type of dam, cement sand and gravel dam（CSG dam) has wide prospects of development. Currently, the stress and stability analysis of the dam is mainly based on the finite element method, which is lack of practical engineering verification. Therefore, model test is one of the important methods to analyze the structure and stability of dam. Systematic research of model test on CSG dam is rare around the world. This paper intended to carry out the systematical research on the model test of CSG dam. Firstly, based on the physical and mechanical characteristics of CSG material, developed similarity theory of the CSG dam model test, deduced the similar theoretical research on CSG dam model, ascertained physical mechanics parameter and get the similarity index of model, and prepared similar material of model. Secondly, according to the characteristics of the CSG dam, constructed model test method, updated test measurement means, and improved analysis method of model test. Finally, carried out the structural model test of CSG dam based on the above research, get the stress and deformation state of the dam, determined the ultimate bearing capacity of the dam. The geo-mechanical model test under complex conditions is launched, obtained the instability mechanism of the dam, explored the stability relationship between CSG dam and foundation, bearing capacity of foundation is deduced as well. With the above conclusions, it will promote the rapid development of CSG dams.

胶凝砂砾石坝作为一种新坝型，发展前景广阔。然而其现有的应力及稳定分析以有限元方法为主，缺少实际工程验证，因此需要进行模型试验以验证计算方法的合理性。模型试验方法是分析坝体结构及稳定问题的重要手段之一，基于胶凝砂砾石坝的模型试验的系统性研究国内外少有报告。本课题拟开展胶凝砂砾石坝模型试验系统研究，首先，围绕胶凝砂砾石材料物理力学特性，开展胶凝砂砾石坝模型试验相似理论研究，确定模型试验物理力学参量，得到模型相似指标，最终研制出模型相似材料。其次，针对胶凝砂砾石坝特点，构建胶凝砂砾石坝模型试验方法，更新试验量测手段，完善试验分析方法。最后，在上述研究的基础上，开展结构模型试验，得到坝体应力和变形状态，确定坝体结构本身的极限承载能力；开展复杂地基条件下的地质力学模型试验，得到坝体的失稳机理，探讨胶凝砂砾石坝与地基的稳定关系，确定地基承载能力。通过上述结论，促进胶凝砂砾石坝快速发展。

胶凝砂砾石坝作为一种新坝型，发展前景广阔，针对其现有的应力及稳定分析以有限元方法为主，缺少实际工程验证的特点，因此需要进行模型试验以验证计算方法的合理性。模型试验方法是分析坝体结构及稳定问题的重要手段之一，基于胶凝砂砾石坝的模型试验的系统性研究国内外少有报告，本课题系统地开展了胶凝砂砾石坝模型试验研究，。首先，围绕胶凝砂砾石材料物理力学特性，开展胶凝砂砾石坝模型试验相似理论研究，确定模型试验物理力学参量，得到模型相似指标，研制出了胶凝砂砾石坝模型相似材料，并开展了基于敏感性分析及BP神经网络的模型材料配合比研究，提高了模型材料选配效率。针对胶凝砂砾石坝特点，完善了胶凝砂砾石坝模型试验方法。在上述研究的基础上，开展了守口堡胶凝砂砾石坝结构模型试验，得到坝体应力和变形状态，确定坝体结构本身的极限承载能力；结合守口堡大坝与武都的地质条件，开展了复杂地基条件下的地质力学模型试验，得到了坝体的失稳机理，探讨胶凝砂砾石坝与地基的稳定关系，确定地基承载能力。