Department of Geotechnical Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
College of Water Resources and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China.
Sensors (Basel). 2021 Sep 18;21(18):6280. doi: 10.3390/s21186280.
Clay-gravel mixture has been widely used in high embankment dams and understanding its seepage characteristics is critical to dam safety. From the instrumental perspective, the realization of continuous pressurized water supply becomes a key technical challenge, significantly restricting the working conditions replicated in previous seepage apparatuses. To this end, a novel water provision system, relying on parallel-disposed sensor-based pressure devices, was introduced, so that the application of an existing large-scale stress-controlled apparatus can be expanded to long-term seepage tests regarding coarse-grained cohesive soils. Constant-head permeability tests were conducted on original-graded clay-gravel mixtures to investigate their hydraulic properties, incorporating the influence of stress relaxation. Test results show that with 35% gravel content, the clay-gravel mixture is suitable for dam construction as the core material. The stress relaxation holds a marginal effect on the hydraulic conductivity of soil. The functionality of this improved apparatus is verified, especially under long-term seepage conditions.
砾质粘土混合物已被广泛应用于高土石坝中，了解其渗流特性对大坝安全至关重要。从仪器设备的角度来看，实现连续加压供水是一个关键的技术挑战，这极大地限制了以往渗流设备所能够复制的工作条件。为此，引入了一种新的供水系统，该系统依赖于基于传感器的平行布置的压力设备，从而可以将现有的大型应力控制设备的应用扩展到针对粗粒粘性土的长期渗流测试。对原状级配砾质粘土混合物进行了常水头渗透试验，以研究其水力特性，并考虑了应力松弛的影响。试验结果表明，当砾石含量为 35%时，砾质粘土混合物适合作为核心材料用于大坝建设。应力松弛对土的渗透系数影响不大。该改进设备的功能得到了验证，特别是在长期渗流条件下。
