Effect of Soil Types on The Development of Matric Suction and Volumetric Water Content for Dike Embankment During Overtopping Tests

Abstract

The resistance of dike materials has a great effect on the development of hydraulic engineering around the world. It helps to understand the mechanism of dike failure occurred due to the influence of hydraulics and Geotechnical parameters. The overtopping moment is one of the main failures that reduces the stability of the dike embankment through initiating the breach channel inside dike crest as a result of water flow above the downstream slope of the dike. Two spatial overtopping tests were conducted at in Hydraulic Geotechnical laboratories at the University Sains of Malaysia to observe the evolution of matric suction and volumetric water content for two soil types of sand and very silty sand soils. A pilot channel was cut in dike crest along the side wall of the small flume channel to represent the transition water flow from upstream into downstream slopes during overtopping test. The results indicated that the matric suction decreases due to the increase of volumetric water content during the saturation of dike body. The proportion increasing and decreasing of volumetric water content and matric suction is lower in very silty sand than those in sand soil due to the presence of fine particles in previous soil.

Effects of Soil Properties and Illumination Intensities on Matric Suction of Vegetated Soil

“…For both vegetated soil and bare soil, only a diameter of 100 mm in the center of test boxes was subjected to lighting, and the monitoring period was 10 days (Figure 3d,e). Soil characteristics (e.g., plastic limit, liquid limit, clay, and silt content) have an important impact on the distribution of soil matric suction and soil-water retention [35][36][37]. The third series of tests was the repetition of the first series, but with the different soil properties as shown in Table 1 and Figure 1, namely, fine sandy loam, sandy silt, and silty clay, and the monitoring period was 10 Soil characteristics (e.g., plastic limit, liquid limit, clay, and silt content) have an important impact on the distribution of soil matric suction and soil-water retention [35][36][37].…”

“…Soil characteristics (e.g., plastic limit, liquid limit, clay, and silt content) have an important impact on the distribution of soil matric suction and soil-water retention [35][36][37]. The third series of tests was the repetition of the first series, but with the different soil properties as shown in Table 1 and Figure 1, namely, fine sandy loam, sandy silt, and silty clay, and the monitoring period was 10 Soil characteristics (e.g., plastic limit, liquid limit, clay, and silt content) have an important impact on the distribution of soil matric suction and soil-water retention [35][36][37]. The third series of tests was the repetition of the first series, but with the different soil properties as shown in Table 1 and Figure 1, namely, fine sandy loam, sandy silt, and silty clay, and the monitoring period was 10 days.…”

“…Matric suction in the sandy silt was higher than that of the silty clay, and this result may be explained by the pore structure between silt particles being more conducive to the capillarity of unsaturated soil, while the interaction of clay particles and water produces bound water with a strong viscosity [49,51]. Meanwhile, the small granularity of silty clay limits water transport in the capillary channels of the soil, and the capillarity is relatively weak [34,37]. In addition, the matric suction of silty clay increased rapidly in the initial stages of the test evidenced that when the content of clay particles and fine particles is high, the soil matric suction is sensitive to the change in soil moisture content, which mainly depend on the difficulty of draining or uptaking water from the soil [19,37,52].…”

“…Meanwhile, the small granularity of silty clay limits water transport in the capillary channels of the soil, and the capillarity is relatively weak [34,37]. In addition, the matric suction of silty clay increased rapidly in the initial stages of the test evidenced that when the content of clay particles and fine particles is high, the soil matric suction is sensitive to the change in soil moisture content, which mainly depend on the difficulty of draining or uptaking water from the soil [19,37,52]. Figure 15 shows that during the wetting process, the matric suction of each specimen gradually decreased over time.…”