盾构管片预埋槽道受力性能分析

盾构管片预埋槽道技术近年来逐渐在轨道交通工程中得到应用,但对于区间内管线及设备如接触网、疏散平台等具体安装方式及槽道螺栓的受力性能鲜有报道,尤其随着大直径管片(直径6 m及以上)应用的增多,高净空下接触网的安装方式一直是争论的焦点。提出预埋槽道T形螺栓固定点的最大单点工作荷载为8 kN,对接触网、疏散平台等盾构区间内管线与设备的安装方式及受力特点逐一进行探讨,重点研究高净空下接触网的安装难题;然后在现场拼装完成的管片上对槽道及T形螺栓进行拉拔、剪切试验。经分析,接触网螺栓受力最大,但满足工作荷载限值要求;通过试验验证了在接触网专业要求的3倍工作荷载条件下,槽道不变形、管片不开裂,在实践层面上进一步证明T形螺栓工作荷载及管线与设备的安装方式的合理性。

Analysis on the Mechanical Performance of Embedded Chute in Shield Segment

Embedded chute in shield segment has been gradually applied in rail transit engineering in recent years. However, there are few reports on the specific installation methods for pipeline and such equipment as catenary, evacuation platform and the mechanical performance of bolts in the embedded chute, and the installation method for catenary under high clearance has been the focus of controversy with the increasing application of large diameter segment(diameter 6 m or more). In this paper, the maximum single point working load of the fixed point of the T-shaped bolt in the embedded chute is 8 kN, and the installation mode and mechanical performance of the pipeline and such equipment in the shield interval, such as the catenary and the evacuation platform, are discussed one by one, and the problems in catenary installation under high clearance are studied emphatically. Then the T-type bolts in embedded chute are pulled out and sheared in the field. The results of analysis show that the catenary bolt bears the largest stress, but it meets the working load limit requirement. The test verifies that the embedded chute does not deform and the segment does not crack under the working load three times the catenary professional requirement. In practice, it further proves that the working load of T-shaped bolt and the installation mode of pipeline and equipment are rational.