Experimental PIV Radial Splitting Study on Expansive Soil during the Drying Process

Abstract

Expansive soil is prone to shrinkage and cracking during the drying process, leading to strength and permeability problems that exist widely in water conservancy projects and geotechnical engineering, including foundation pits and cracks at the bottom of channels and slopes. Such problems are closely related to the tensile strength of the soil. In this study, Nanyang expansive soil is taken as the research object and radial splitting tests were performed using a particle image velocimetry (PIV) test system on both undisturbed and remolded expansive soil during the drying process. The results indicated that the load–displacement curve of the undisturbed and remolded expansive soil specimens showed a strain-softening phenomenon and that the peak load increased with decreasing water content. Under the same other conditions, the peak load of the remolded expansive soil specimen was higher than that of the undisturbed soil specimen, with the undisturbed soil specimen having distinctive structural and fractural features. The load–displacement relation curve, displacement vector field, and fracture characteristics had an obvious one-to-one correspondence in the stage division. The compression deformation stage, crack development stage after the peak value, crack maturity stage, and failure stage could be observed via the PIV technique. Moreover, the fracture characteristics of the remolded specimens were more regular than those of the undisturbed specimens. The above research results provide a scientific basis for the design and construction of geotechnical engineering related to expansive soil.

Effects of Drying and Wetting Process on the Tensile Strength of Granite Residual Soil

“…The absorbed suction caused by liquid surface tension will vary with the change in saturation angle. After the soil particles encounter water, in addition to the bond force generated by chemical action, the surface tension between the particles also increases the attraction between the particles, which is usually called suction stress or absorbed suction [24,25]. The suction between soil particles caused by the surface tension of water and its contact angle with soil particles causes compressive stress between particles, which means the soil particles tend to be close to each other, the expression of absorbed suction is Equation (1).…”

“…The influence of water on the strength of the structure is felt throughout the whole course of the change, and is due not only to the action of water chemistry on the cementing material, but also to the action of water tension between the soil particles [24]. At present, the tensile strength of soil has been studied by using samples with fixed moisture content, but the formation process of the strength has been neglected, and the properties of the tensile strength have been poorly studied [23,25,26].…”

Visualized Experimental Study of Soil Temperature Distribution around Submarine Buried Offshore Pipeline Based on Transparent Soil

“…Transparent soil test technology can realize the visualization of the displacement of soil. The previous studies of transparent soil test mainly focus on the physical and mechanical properties of transparent soil materials [7][8][9][10][11] or use transparent soil tests to study the deformation of soil around the pile, tunnel, anchor or other structures [12][13][14][15][16]. The transparency of the transparent soil is expected to be improved for larger model tests.…”

A Rapid Bridge Crack Detection Method Based on Deep Learning

“…This is due to the uneven settlement of the bridge foundation in the vertical direction and displacement in the horizontal direction, leading to internal stresses in the concrete structure and resulting in cracks [6]. For foundations that are built in phases or subjected to the effects of frost in cold areas, deformation of the structure and cracks can also occur [7,8]. Additionally, bridge cracks can cause significant harm: (1) Cracks can result in leaks, causing water flow to into the interior of the bridge and destroying the concrete's mechanical characteristics and physical properties.…”