Research on deformation characteristics of surface and segment on the double line shield tunnel underpassing riverway
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.
metroshield tunnelsurface humpuplifting of segmentsgrouting pressuregrouting material
万方数据
维普
