A method to estimate the jacking force for pipe jacking in sandy soils

Ji, Xinbo; Zhao, Wen; Ni, Pengpeng; Barla, Marco; Han, Jiqing; Jia, Pengjiao; Chen, Yang; Zhang, Chaozhe

doi:10.1016/j.tust.2019.04.002

Cited by 55 publications

(26 citation statements)

References 28 publications

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“…In pipe jacking, the linear factors to generate friction resistance are due to the weight of pipe (f W ), soil pressure (f s ), slurry pressure (f m ), pipe-soil cohesion (f sc ), and pipe-slurry cohesion (f mc ). Their equations can be expressed as [5,6,9,10,14,19,21,22,25,26].…”

Section: Overview Of the Existing Prediction Models Of Friction Resismentioning

confidence: 99%

“…f mc = c m B m (5) where µ s and µ m are the kinematic friction coefficient of pipe-soil and pipe-slurry, respectively; W is the weight of pipe per unit length, kN/m; N is the total normal force acting on the pipe, kN/m; c s and c m are the pipe-soil cohesion resistance and pipe-slurry cohesion resistance, respectively, kPa; B s and B m are the pipe-soil contact width and pipe-slurry contact width, respectively, m. Some hypotheses have been made to establish the prediction models, by which one or some of the items listed above should be considered. Typical hypotheses are: Hypothesis 1.…”

Section: Overview Of the Existing Prediction Models Of Friction Resismentioning

confidence: 99%

“…Hypothesis 3. The excavated tunnel is unstable, the surrounding soil collapses and is in full contact with the whole area of the jacking pipes (see Figure 2c) [5,6,9,21,26].…”

Section: Hypothesismentioning

confidence: 99%

“…To calculate Equation 18, the vertical soil stress σ v has to be first determined. It is noted that at the present time, by far the most commonly used model for soil pressure calculation is Terzaghi's silo model (Equation (22)) [5,6,9,19,21,26]. According to Equation (22), the calculation of the vertical soil stress requires some physical parameters that may be determined with some accuracy, such as the height of cover h, the cohesion c s , and the unit weight of soil γ, but also some empirical parameters, such as b, δ, and K. The definition of these empirical parameters varies from one author to another.…”

Section: Calculation Of Friction Resistance For Slurry Pipe Jackingmentioning

confidence: 99%

“…It has many a jacking machine, from a drive shaft to a reception shaft, as illustrated in Figure 1. It has many technical merits, such as a short time limit, high security, low environmental effect, and little traffic disturbance [3][4][5][6]. Because of that, pipe jacking has been widely used in the construction of infrastructure for traffic and transportation systems in cities [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Prediction of Friction Resistance for Slurry Pipe Jacking

Peng

Zhou

et al. 2019

Applied Sciences

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Friction resistance usually constitutes one of the two main components for the calculation of required jacking force. This paper provides a new approach to predict the friction resistance of slurry pipe jacking. First, the existing prediction equations and their establishment methods and essential hypotheses used were carefully summarized and compared, providing good foundations for the establishment of the new model. It was found that the friction resistance can be uniformly 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. The critical quantity of pipe-soil contact angle (or width) involved may be calculated by Persson’s contact model. Then, the equation of normal force was rederived and determined, in which the vertical soil stress should be calculated by Terzaghi’s silo model with parameters proposed by the UK Pipe Jacking Association. Different from the existing prediction models, this new approach has taken into full consideration the effect of lubrication, soil properties (such as internal friction angle, cohesion, and void ratio), and design parameters (such as buried depth, overcut, and pipe diameter). In addition, four field cases and a numerical simulation case with various soils and design parameters were carefully selected to check out the capability of the new model. There was greater satisfaction with the measured data as compared to the existing models and the numerical simulation approach, indicating that the new approach not only has higher accuracy but is also more flexible and has a wider applicability. Finally, the influence of buried depth, overcut, and pipe diameter on the friction resistance and lubrication efficiency were analyzed, and the results can be helpful for the future design.

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Section: Overview Of the Existing Prediction Models Of Friction Resismentioning

confidence: 99%

Section: Overview Of the Existing Prediction Models Of Friction Resismentioning

confidence: 99%

“…Hypothesis 3. The excavated tunnel is unstable, the surrounding soil collapses and is in full contact with the whole area of the jacking pipes (see Figure 2c) [5,6,9,21,26].…”

Section: Hypothesismentioning

confidence: 99%