Development of Similar Materials for Liquid-Solid Coupling and Its Application in Water Outburst and Mud Outburst Model Test of Deep Tunnel

Abstract

In order to explore the evolution mechanism of water and mud inrush, based on the fluid-solid coupling similarity theory and a large number of matching tests, fault similar materials with mountain sand, gravel, and red clay as raw materials and surrounding similar rock materials with mountain sand, red clay, cement, and water as raw materials are developed. Similar materials’ physical and mechanical properties and hydraulic properties with different ratios are tested and analyzed. The results show that the red clay content influences the mechanical properties of similar materials and their hydraulic properties, and the gravel substrate mainly influences the fault permeability coefficient. Similar material can be adjusted within a certain range of mechanical parameters. The material is simple and suitable for developing similar materials for different low and medium strength rock masses. Finally, a similar material was used in a model test of the tunnel fault fracture zone to reveal the mechanism of water and mud bursts in the tunnel. The study results can be used as a reference for the development of similar materials for tunnel fracture zone surrounding rocks.

Investigation on Carbonation and Permeability of Concrete with Rice Hush Ash and Shop Solution Addition

“…It is also observed from Table 4 that the coefficient of permeability of concrete for 2% soap solution significantly decreases with increasing percentage of rice hush ash content. Further, from Table 4 , it is also observed that the change in the coefficient of permeability of concrete made with partial replacement of cement by different percentages of RHA of 5%, 10% and 15%, compared to that concrete made with 1% and 2% soap solution concentration and without RHA, are −34.48%, −27.58% and −31.03%, and 85.17%, 85.86% and 85.51%, respectively [ 50 , 51 , 52 , 53 , 54 ]. It is observed that the coefficient of permeability of concrete with 1% soap solution showed negligible change whereas the coefficient of permeability of concrete with 2% soap solution was reduced by 85.86% compared to mix M1.…”

“…The coefficient of permeability of concrete made with 2% soap solution showed a significant reduction compared to mix M1 and this may be due to the hydrophobic action of soap solution in concrete which repels the water ingress. The coefficient of permeability of concrete made with different percentages of RHA (5%, 10% and 15%) compared to that of concrete made with 1% soap solution shows higher coefficient of permeability whereas when compared with 2 percent soap solution no significant change is observed [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]. A plot is made between coefficient of permeability of concrete and different percentage RHA for 1 and 2 percent of soap solution as shown in Figure 7 .…”

“…From the permeability result, it is also found that coefficient of permeability with 2 percent soap solution is very much less in comparison with 0 percent soap solution. From the observation of SEM images, it can be said that soap solution helps in filling the voids of concrete which ultimately helps in reduction in permeability [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. EDX analyses of concrete with 0% (M1) and 2 % (M6) soap solution are shown in Figure 9 and Figure 10 respectively.…”

Comparative Study on the Behavior of Reinforced Concrete Beam Retrofitted with CFRP Strengthening Techniques

“…A maximum load of 224 kN was reported. As the testing continued to the maximum load, no cracks were observed, but bending cracks spread in the positive moment zone [ 67 , 68 , 69 ]. The beam failed due to normal steel yielding prior to concrete crushing, with the concrete crushing happening precisely around the point load [ 1 , 2 , 3 ].…”

The effects of the COVID-19 pandemic on the mental health of workers and the associated social-economic aspects: A narrative review

“…Data obtained from China's healthcare system assessed the impact of social media exposure on mental health. They unveiled that upon curfew enforcement in Wuhan, between half to two-thirds of the citizens with selfreported intense internet surfing were grappled with MDS, and about 25% experienced combined symptomatology of depression and anxiousness, which is two-fold greater than individuals with restricted social media usage during the same period [49,63]. United Nations (U.N.) had predicted the 2020 escape rate from extreme poverty to be 2.3 people/second; however, this rate was assessed to be -154.9 people/minute in 2020 [59,78].…”