This article takes the shield tunneling of Suzhou metro line 8 underpassing Zhongtang river as a case,and uses Midas GTS NX finite element simulation and on-site measurement analysis methods to explore the deformation characteristics of the surface and segments when the double line shield tunneling underpasses an existing riverway.It also discusses the influence of different grouting pressures and grouting material properties on the surface deformation when the double line shield tunneling underpasses the riverway.Research has shown that the surface deformation caused by double line shield tunnels under passing rivers exhibits a significant"synergistic effect".The maximum surface hump caused by the completion of double line tunnel excavation is about 1.5 times that of single line.The segments exhibit varying degrees of"uplifting"characteristics.The vertical displacement of the right segments is slightly greater than that of the left segments,and the maximum horizontal displacement occurs at an angle of about 45° below the outer side of the segment.The grouting pressure,elastic modulus of grouting material,and surface deformation are approximately linearly positively correlated.Considering the reason for the uplifting of segments,it is not advisable to choose grouting materials with excessive elastic modulus when underpassing rivers.The selected grouting materials with elastic modulus around 10 MPa should be adequate.It is also recommended to control the grouting pressure at 0.2-0.3 MPa at the same time.
关键词
地铁/盾构隧道/地表隆起/管片上浮/注浆压力/注浆材料
Key words
metro/shield tunnel/surface hump/uplifting of segments/grouting pressure/grouting material
维普
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