Study on the Mechanical Properties of the Foundation under the Crawler Crane in Soft Soil Area

Introduction: Most of the existing patents reported the structural composition of the subgrade box of the crawler crane, and few of them have focused on the mechanical properties of the foundation. The paper aims to select the subgrade box size for lifting the shield mainframe in a soft soil area, and check the bearing capacity and settlement of the underlying stratum. Methods: The maximum and minimum pressures transferred by the track plate are determined, and a method for determining the equivalent load of the track plate is proposed and validated. The subgrade box size of a 600t crawler crane is selected, and the bearing capacity and settlement of the clay layer and muddy soil layer are analyzed. Results: The eccentric distance e = L/6 is the most unfavorable state when the crawler crane works normally on the subgrade box, and the equivalent load at the foundation bottom is maximum at this time. The equivalent uniform load qe is obtained. The selected subgrade box size of crawler crane is 17 m × 8.5 m. Discussion: The proposed equivalent load method provides ideas for selecting the subgrade box size of crawler crane, and analyzing the bearing capacity and deformation of the foundation. Later, the mechanical properties of the foundation will be studied when the crawler crane travels on the subgrade box. Conclusion: The proposed equivalent load method can be applied to select the subgrade box size. Emphasizing the bearing capacity and deformation of the foundation, the method greatly ensures the safety of the crawler crane when it is working eccentrically.