Monitoring of Over Cutting Area and Lubrication Distribution in a Large Slurry Pipe Jacking Operation

Abstract

Slurry pipe jacking was firmly established as a special method for the non-disruptive construction of the underground pipelines of sewage systems. Pipe jacking, in its traditional form, has occasionally been used for short railways, roads, rivers, and other projects. Basically the system involves the pushing or thrusting of concrete pipes into the ground by a number of jacks.In slurry pipe jacking, during the pushing process, mud slurry and lubricant are injected into the face and the over cutting area that is between the concrete pipes and the surrounding soil. Next, the slurry fills voids and the soil stabilizes due to the created slurry cake around the pipes. Fillings also reduce the jacking force or thrust during operation. When the drivage and pushing processes are finished, a mortar injection into the over cutting area is carried out in order to maintain permanent stability of the surrounding soil and the over cutting area. Successful lubrication around the pipes is extremely important in a large diameter slurry pipe jacking operation.Control of lubrication and gaps between pipes and soil can prevent hazards such as surface settlement and increases in thrust. Also, to find voids around the pipes after the jacking process, in order to inject mortar for permanent stabilizing, an investigation around the pipes is necessary. To meet these aims, this paper is concerned with the utilization of known methods such as the GPR (Ground Penetrating Radar) system and borehole camera to maintain control of the over cutting area and lubricant distribution around the pipes during a site investigation. From this point of view, experiments were carried out during a tunnel construction using one of the largest cases of slurry pipe jacking in Fujisawa city, Japan. The advantages and disadvantages of each system were clarified during the tests.

A New Approach for Determination of Adhesion Coefficient in Pipejacking Method by Experimental and Numerical Analysis: An Example from Istanbul

“…When the slurry fills the soil voids, the soil is stabilised because of the slurry pressure. Also the mud slurry plays an important role in reducing the friction resistance and jacking loads in pushing the pipes 10 …”

Prediction of Friction Resistance for Slurry Pipe Jacking

“…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].…”

“…The main component of the jacking force is due to frictional resistance. Application of a lubricant such as bentonite slurry in pipe jacking (so-called 'slurry pipe jacking') is essential to reduce the friction resistance and, therefore, the jacking force [3,[10][11][12][13]. However, the use of slurry makes it more complex to calculate or predict the friction resistance because of the change in contact conditions between the pipe and soil and lubricant slurry.…”

“…However, the use of slurry makes it more complex to calculate or predict the friction resistance because of the change in contact conditions between the pipe and soil and lubricant slurry. The new contact state, which is due to the pipe-soilslurry interaction, is affected by factors such as pipe diameter, soil properties, overcut [3,9], lubrication efficiency [9], pipeline misalignments [10,[14][15][16], and stoppages [9,14,[17][18][19]. The existing prediction models have not fully taken these factors into consideration, leading to an overestimation or underestimation of the friction resistance [9,[20][21][22][23].…”

Numerical Analysis of Face Stability of Slurry Pipe Jacking Tunnel in Frozen Ground

“…Among which, pipe jacking is a non-destructive trenchless technique used for installing pipes under the ground using a tunnel boring machine and hydraulic jacks located inside a launch jacking pit (Chapman & Ichioka, 1999;Choo & Ong, 2015;Khazaei, Shimada, Kawai, Yotsumoto, & Matsui, 2006;Pipe Jacking Association, 1995;Rahjoo, Najafi, Williammee, & Khankarli, 2012;Shimada, Khazaei, & Matsui, 2004). A shield is inserted into the ground through a launch shaft or reception shaft and cuts a bore.…”