Mechanical test device and method for simulating pile end resistance and neutral point change

The invention discloses a mechanical test device and method for simulating pile end resistance and neutral point change. The test device comprises a loading system, a rectangular model box, a support system, a pile foundation with side wings, a pile end soil simulation device and a measurement system. According to the measuring method, when the loading mechanism adopts a pile foundation pressurizing device, a pile foundation generates positive frictional resistance; and when the loading mechanism adopts a pile loading pressurizing device, the pile foundation generates negative friction resistance. The side wings bend upwards and downwards along with a soil body around a pile, a displacement field of the soil around the pile can be obtained according to the bending of the side wings, and the position of a neutral point is analyzed according to an interpolation method; a pile end spring deforms, and the pile end axial force, namely the end resistance, can be measured according to a deformation amount. The mecha