Abstract: To study the influence of parallel jacking construction of double steel pipe jacking on adjacent high-pressure gas pipelines in medium-coarse sand strata, the Beijiang Water Diversion Project in Guangzhou is presented in this paper as a case history. The deformation pattern of gas pipelines during the crossing process of double pipe jacking is analyzed by using numerical simulation, theoretical calculation and field measurements. The main conclusions are as follows: (1) The interaction of double pipe jacking construction leads to significant superposition characteristics of pipeline displacement, and the maximum vertical displacement appears in the double penetration stage. (2) The lateral displacement of the pipeline caused by the construction of the double steel pipe jacking can be ignored; (3) The maximum settlement of the pipeline calculated based on the Peck correction formula is 3.29 mm, which is in good agreement with the numerical simulation value of 2.75 mm and the field measured value of 2.9 mm. All of them are less than the design allowable value of 10mm, which proves the reliability and practicability of the research method. The research results construct the theoretical analysis framework of pipe jacking interaction in sandy strata, and the proposed pipeline deformation prediction method can provide reference for similar projects.

Key words: Medium-Coarse Sand Stratum, Double Steel Pipe Jacking, Gas Pipelines, Numerical Simulation, Peck Correction Formula, Field Measurement