Objective To address the issues of high labor intensity, low operational efficiency and irregular insertion posture associated with manual laying of traditional Salix grid sand barriers, this study designed an automatic laying device and proposed a zigzag layout pattern for Salix sand barriers. Particular attention was devoted to the structural design and performance optimization of the core branch insertion mechanism, so as to mitigate branch deflection and excessive insertion inclination, thereby providing design references for the development of sand barrier laying equipment in sandy regions.

Method A flexible pressure roller extrusion method was employed to insert Salix branches of varying diameters. A mechanical model of the insertion process was established, and force analysis was conducted on both the pressure roller and the Salix branches. The cause of the insertion inclination angle was analyzed: the insertion direction of the Salix is subject to fluid resistance from the sandy soil. As the insertion depth increases, the velocity of the Salix branch entering the soil decreases. The deceleration displacement was solved and used to construct a geometric relationship with the initial insertion point and the insertion depth, yielding the theoretical deflection angle of the Salix branch.

Result (1) The composite motion formed by the equipment advancing and the branch being vertically inserted into the soil causes sand resistance to hinder the horizontal movement of the branch bottom end, which is the main reason for the insertion inclination angle. When the insertion depth exceeds 60 mm, soil resistance significantly attenuates the horizontal velocity at the bottom end, resulting in a horizontal displacement difference between the upper and lower ends of the branch and leading to an increase in the insertion inclination angle. (2) The insertion inclination angle increases monotonically with the speed-to-rotation ratio; the larger the ratio, the greater the branch tilt angle. Increasing the pressure roller rotation speed or reducing the laying travel speed can both decrease the insertion inclination angle. (3) Within the optimal parameter range (pressure roller rotation speed 100–200 r/min, laying speed 600–1500 mm/s), when r is approximately 7, the insertion inclination angle can be stably controlled within 10°. Beyond this range, the inclination angle increases rapidly and steeply, failing to meet the sand barrier laying process standards. (4) Under optimal parameter conditions, the equipment can adapt to full-size Salix psammophila branches of 9–12 mm, with regular insertion posture, branch insertion success rate reached 88.3%, and the complete machine demonstrates excellent operational stability.

Conclusion The Salix grid sand barrier laying device designed in this study is suitable for flat and gently sloped terrain. Focusing on the branch insertion mechanism, its rationality was analyzed and verified. The structural design of the insertion mechanism was completed. The influence of different operating parameters on sand barrier formation quality was investigated, and optimal operating parameters were determined. This work provides a reference for the design and optimization of Salix grid sand barrier laying mechanisms.