Calculation of Friction Force for Slurry Pipe Jacking considering Soil‐Slurry‐Pipe Interaction

Abstract

This paper aims to provide a new approach to predict the friction resistance of slurry pipe jacking. Friction force usually constitutes the main component of jacking force. It can be calculated by multiplying an effective friction coefficient and the normal force acting on the external surface of the pipe. This effective friction coefficient is introduced to reflect the effect of contact state of pipe soil slurry, highly affected by the effect of lubrication and the interaction of pipe soil slurry. Firstly, by making some reasonable assumptions, the analytical formula of the effective friction coefficient is obtained, in which the critical quantity of contact (contact angle or width) is calculated by using the Persson contact model. Then, the analytical formula of normal force of circular pipeline is derived, which needs to determine the vertical soil pressure. To allow for a better prediction, three typical silo models are introduced and compared. Finally, a method for calculating the friction resistance of slurry pipe jacking is established. The main difference from the existing method is that this method takes into full consideration the influence of lubrication, soil properties (such as internal friction angle, cohesion, and void ratio), and design parameters (such as buried depth, overcut, and pipe diameter). By using reasonable silo models, the predicted results are in good agreement with the measured values collected from 10 in situ cases, which proves that the new approach can provide accuracy prediction of friction resistance for slurry pipe jacking with various soil conditions, and it may help for better future design and less construction costs.

Development and Field Application of an Automated Pipe Jacking Friction Resistance Identification and Warning System in Construction

“…Lubrication: Lubrication is a key factor in reducing frictional resistance; therefore, lubrication has a significant impact on frictional resistance [1,23,24]. 2.…”

“…Pipe-soil contact: Pipe-soil contact increases frictional resistance, but the specific proportion depends on the degree and conditions of the pipe-soil contact [7,16,24,25].…”

“…Design parameters: Design parameters, including burial depth, pipe diameter, and overcut, exert influence on the frictional resistance; however, the specific weight depends on the specific design conditions [3,24,26,27]. 5.…”

Research on the Slurry for Long‐Distance Large‐Diameter Pipe Jacking in Expansive Soil

“…And many monitoring results showed that the jacking force is much smaller than the jacking force calculated by this model. If that the pipe was completely covered by slurry sleeve in the process of pipe jacking, Ye et al [15] proposed a solid-liquid contact model to calculate the pipe jacking force. Zhang et al [16] divided the contact outside the pipe into the pipe-soil contact and the pipe-slurry-soil contact to calculate the contact friction force of the two parts, respectively.…”

Frictional resistance calculation and jacking force prediction of rectangular pipe jacking

“…The initial segment solely analyzed pipe–soil contact, asserting that frictional resistance equated to the earth pressure on the pipe jacking multiplied by the pipe–soil friction coefficient 1 – 5 . In the subsequent phase, exclusive attention was directed towards pipe–slurry contact, involving an assessment of thixotropic slurry as a power-law fluid and utilizing a fluid flat model to compute the pipe–slurry shear stress 6 , 7 . The final part encompassed both pipe–soil and pipe–slurry contact analyses, presuming that thixotropic slurry could not entirely envelop the pipe sections, thus maintaining contact with both soil and slurry during pipe jacking 8 – 12 .…”