心墙高塑性黏土与垫层裂缝渗透实验研究

为了从实际工程的角度更深一步地对黏土心墙混凝土垫层裂缝接触冲刷和填充保护进行研究,通过不同的仪器方案的对比以及实验仪器和试验方法的改进,建立了针对黏土心墙混凝土垫层裂缝接触渗流的实验方法。通过不同条件下的渗流特性试验,探讨了混凝土垫层裂缝对坝体抗渗性的影响因素。对试验数据进行分析后,得出以下结论:缝宽的影响,工程中反滤层下的垫层及廊道混凝土裂缝应小于1.0 mm,超过1.0 mm的裂缝应当做适当处理;压应力的影响,当应力达到0.5 MPa及以上时,在反滤层保护下,围压的作用可以延迟接触冲刷破坏的发生;反滤措施的作用和影响,渗透水中进入裂缝的黏土颗粒由于下游反滤层的保护作用逐渐停滞下来并对裂缝进行了填充。

Infiltration experimental study of cracks between high plasticity clay earth core dam and cushion layer

For thorough research of contact scouring and filling protection problems for concrete cushion layer cracks in clay core dam in terms of the practical engineering, the contact seepage test method of concrete cushion layer cracks in the clay earth core dam was established by comparing different instrument schemes and by improvements of experimental apparatus and test methods. The influence factors of concrete cushion layer cracks on dam impermeability were discussed according to the seepage charactersitics tests with different conditions. After the test data analysis, the following conclusions were drawn: as to the effects of crack width, the concrete cracks of cushion layer and corridor under the filter layer should be less than 1.0mm, the cracks over 1.0mm should be properly treated; Effects of compressive stress. When the stress reached 0.5MPa or larger, compressive stress can delay the occurrence of contact scouring destruction under filter layer''s protection; Effects and influences of filter layer measures. The clay particles which entered the cracks from the percolated water slowed down gradually due to the protective effects of the downstream filter layer and filled the crack.