Effect of Fatty Acids Addition into Backfilling Material in Over-cutting Area on Improvement of Lubrication Performance for Pipe Jacking

Maehara, Kazuki; Sasaoka, Takashi; Hamanaka, Akihiro; Shimada, Hideki

doi:10.2174/1874149501913010281

Cited by 4 publications

(1 citation statement)

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“…Xia [15] considered that the groundwater level changes with the change in the surrounding environment and obtained the stresses, settlement deformation of different parts of the integrated pipe corridor and the change law of soil stress around the corridor by numerical simulation for a large integrated pipe corridor with a determined burial depth. Maehara et al [16] injected fatty acids as lubricant between the pipe and the surrounding soil to reduce the frictional resistance. With the increase in fatty acid addition, the leakage rate of the filler decreased, but excessive addition would lead to water absorption in the pipe, and the addition amount of approximately 3% was the best for soil settlement reduction.…”

Section: Introductionmentioning

confidence: 99%

Simulation analysis of the effect of single-chamber double-line pipe jacking through different soil materials on surface uplift and subsidence

Jia

Jiao²,

Liu³

et al. 2022

PLoS ONE

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This article is based on the relocation project of the 330 kV overhead line in Xi’an, China. In this paper, the soil settlement under different jacking depths was calculated by using the modified Peck’s formula. Meanwhile, by modeling in ABAQUS, the jacking process of a single-chamber double-line large diameter pipeline under different soil conditions was simulated, and the ground deformation data under the different simulated working conditions were obtained. The results of the two methods were compared with the construction monitoring results, and it was found that the finite element simulation results were closer to the actual results. The control variable method was used in the analysis of the surface soil deformation law to analyze the effect of different soil parameters and pipe jacking depths on surface soil deformation. Finally, the best soil conditions applicable to single-chamber double-line large diameter pipe jacking construction were obtained through comparative analysis. The results show that (1) when using double-line construction, the maximum surface settlement under different soil conditions is located 11–15 m from the centerline of the soil above the pipeline, the minimum settlement location is inside the isolation pile, and with the increase in jacking distance, the settlement at the same section of the surface will gradually decrease and finally produce a small uplift. (2) In the first jacking, the settlement of powder clay is the largest, and the maximum settlement points in the surface section are more distributed. The maximum settlement value is approximately 11.66 mm. The settlement of powder soil is the smallest but produces a certain uplift deformation, and its maximum settlement is more concentrated in the surface section. After the comparison of deformation and soil parameters, loess-like soil is more suitable for single-compartment double-line large diameter pipe jacking construction. (3) When the top pipe burial depth changes, the greater the burial depth is, the smaller the settlement but the greater the lateral influence range. In the soil parameters, the modulus of elasticity only changes 3 MPa, and the settlement change value is approximately 5 mm. By changing the parameters, it can be obtained that the larger the modulus of elasticity of the soil is, the smaller its deformation. The larger the internal friction angle of the soil is, the smaller its deformation, but the maximum value of settlement change is only 1.7 mm, which means that the change in the internal friction angle has little effect on the soil deformation.

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Section: Introductionmentioning

confidence: 99%