Abstract: The double-row pile system has been extensively used in the excavation support due to its advantages such as large lateral resistance stiffness, strong site applicability and convenience. This paper considers the interaction between piles and soil in the form of contact element to study the displacement and internal force of the double-row pile using MIDAS GTS NX. Combined with the field monitoring information, this paper verifies the safety and reliability of the double-row pile supporting structure, which provides reference for related projects. The result shows that by establishing the pile-soil contact surface, the deformation of the double row piles can be simulated more practically. About 3.5 times of the pile diameter is a reasonable pile row spacing, which can make full use of the mechanical properties and space effect of double row piles. About 2 times of the distance between piles in the front row is a reasonable distance between piles in the back row, which can save the project cost in the case of ensuring safety. Making a comparison between the numerical calculation consequences and the monitoring information, this paper verifies the necessity of establishing the pile-soil contact surface elements in the numerical simulation of the double row piles and the rationality of the support scheme of double row piles.

Key words: Pile-Soil Interaction, Contact Surface, Double-Row Piles, Mechanical Performance