热力管线盾构隧道下穿铁路区地表沉降影响研究

STUDY ON THE INFLUENCE OF GROUND SETTLEMENT IN RAILWAY AREA UNDER THERMAL PIPELINE SHIELD TUNNEL

盾构隧道下穿既有铁路掘进施工会引起地基变形及轨道不均匀沉降问题,影响隧道施工和铁路安全运营。为研究盾构隧道掘进过程中对地表变形的影响,依托热力管线下穿京铁路线工程开展研究,采用离心机试验模拟了盾构隧道施工过程中对地表变形的影响。研究结果表明,盾构施工对路基的影响主要集中于25 m范围内,超出该范围的影响可忽略不计;盾构施工过程中,下穿铁路前,路基沉降占整个施工过程引起沉降变形的36%左右,下穿后约占64%;以盾构下穿铁路铁线15 m为界,15 m之前,掘进方向左侧路基沉降大于右侧;15 m之后,掘进方向右侧路基变形大于左侧。研究可为相关工程提供科学依据。

The excavation of the shield tunnel under the existing railway will cause the problems of foundation deformation and uneven settlement of the track,which will affect the safe operation of the railway.In order to study the influence on the surface deformation during the excavation of large-diameter shield tunnels,this paper relies on the thermal pipeline to pass through the Beijing-Baobao railway line,and uses a centrifuge test to simulate the shield tunnel construction process.The research results show that the impact of shield construction on the subgrade is mainly concentrated in the range of 25 m,and the impact beyond the modified range can be ignored.During the shield construction process,before going down the railway,the settlement of the subgrade accounts for 36%of the settlement deformation caused by the entire construction process.Left and right,about 64%after going down;taking the shield tunnel penetrating the railway 15 m as the boundary,the subgrade settlement on the left side in the tunneling direction is greater than that on the right side before 15 m.The research in this paper can provide scientific basis for related projects.