Analysis of variation laws of the earth pressure with section types and groove-width ratios
To explore the influences of section types(rectangular,1/4 arch,1/2 arch)and the groove-width ratio(B/b=1.5∶1,2∶1,3∶1,4∶1)on the earth pressure of the hill-filled cut-and-cover tunnel(HFCCT),this paper used the discrete element software PFC2D to simulate and analyze the evolution laws of the average vertical earth pressure(VEP)on the top of the cut-and-cover tunnel(CCT),the settlement difference between inner and outer soil columns,and the contact force chains among particles.Moreover,the paper analyzed the correlation between the settlement difference and the earth pressure based on the earth pressure theory of culvert and pipe,which was put forward by Gu Anquan,and further modified the function of the above-mentioned theory so as to make it applicable to the different section types and groove-width ratio(B/b).The results show that ① when the B/b is determined,the contact force chains will distribute on the top of the CCT and the average vertical earth pressure(VEP)is greater if the CCT adopts a rectangular section.The average VEP will decrease if the CCT adopts an arched section.Howev-er,there is partly stress concentration at the top of the arched section.② When the section is determined,the average VEP and settlement difference on the top of CCT both increase with the increase of B/b.As the B/b decreases,the slope effect is enhanced,the settlement of the outer soil column reduces gradually,and the interaction between the inner and outer soil columns declines,which makes the VEP on the top of the CCT decrease.(3)The settlement difference between the inner and outer soil columns is linearly related to the additional earth pressure.Compared with the rectangular section,the same additional earth pressure under the arched section is generated by a smaller differential settlement,which benefits the stability of the structure.
万方数据
维普
