Water and sand leakage disasters are likely to occur during construction in water-rich sand layer areas,resulting in ground collapse.The stress-strain action characteristics of discontinuous graded sand under differen...Water and sand leakage disasters are likely to occur during construction in water-rich sand layer areas,resulting in ground collapse.The stress-strain action characteristics of discontinuous graded sand under different internal erosion degrees,and the evolution mechanism of water and sand leakage disasters caused by the internal erosion need to be further explored.Therefore,this paper takes the discontinuous graded sand in a water rich sand layer area in Nanchang City of China as the research object.Considering the influence of different fine particle losses(0,10%,20%and 30%)under the internal erosion of sand,the salt solution method is used to realize the specified loss of fine particles in the internal erosion.The stress-strain behavior after the loss of fine particles due to internal erosion is studied by triaxial shear test.Meanwhile,the physical model test and PFC-CFD method are both used to study the evolution rules of water and sand leakage disaster considered the influence of internal erosion degrees.Results show that:(1)under the same confining pressure,the peak failure strength of sand samples decreases along with the increase of fine particle loss.(2)In the water and sand leakage test of saturated sand,a natural filter channel is formed above the observed soil arch.The greater the loss of fine particles,the steeper and wider the collapse settlement area.(3)The relationship between the cumulative amount of water and sand leakage and time is nonlinear.The total mass loss of sand increases along with the increase of internal erosion degree.(4)After the soil arch is formed around the damaged opening,the sand continues to converge above the soil arch under the action of water flow,resulting in the dense convergence of contact force chains.展开更多
基金funded by the Natural Science Foundation of China(No.41962015).
文摘Water and sand leakage disasters are likely to occur during construction in water-rich sand layer areas,resulting in ground collapse.The stress-strain action characteristics of discontinuous graded sand under different internal erosion degrees,and the evolution mechanism of water and sand leakage disasters caused by the internal erosion need to be further explored.Therefore,this paper takes the discontinuous graded sand in a water rich sand layer area in Nanchang City of China as the research object.Considering the influence of different fine particle losses(0,10%,20%and 30%)under the internal erosion of sand,the salt solution method is used to realize the specified loss of fine particles in the internal erosion.The stress-strain behavior after the loss of fine particles due to internal erosion is studied by triaxial shear test.Meanwhile,the physical model test and PFC-CFD method are both used to study the evolution rules of water and sand leakage disaster considered the influence of internal erosion degrees.Results show that:(1)under the same confining pressure,the peak failure strength of sand samples decreases along with the increase of fine particle loss.(2)In the water and sand leakage test of saturated sand,a natural filter channel is formed above the observed soil arch.The greater the loss of fine particles,the steeper and wider the collapse settlement area.(3)The relationship between the cumulative amount of water and sand leakage and time is nonlinear.The total mass loss of sand increases along with the increase of internal erosion degree.(4)After the soil arch is formed around the damaged opening,the sand continues to converge above the soil arch under the action of water flow,resulting in the dense convergence of contact force chains.
