Relationship curves between pipe-soil frictional resistance and jacking distance of jacking circular and rectangular pipe sections under the different experimental conditions.

(A) Relationship curves between pipe-soil frictional resistance and jacking distance of jacking circular pipe section in sandy soil at different buried depth. (B) Relationship curves between pipe-soil frictional resistance and jacking distance of jacking circular pipe section in coal granular layer at different buried depth. (C) Relationship curves between pipe-soil frictional resistance and jacking distance of jacking rectangular pipe section in sandy soil at different buried depth. (D) Relationship curves between pipe-soil frictional resistance and jacking distance of jacking rectangular pipe section in coal granular layer at different buried depth.