Abstract:This paper focuses on the pressure shock wave generated by the electric explosion of the wire acts on the hole wall of the soil layer and form the belled piles caused by squeezing the soil at the bottom of the pile. The relationship function and simulation model between the explosive energy of the wire and the shock wave pressure are established， and the relationship between the discharge parameters and the shock wave intensity is analyzed. The relationship between shock wave pressure and soil deformation is established， and the pressure required for the deformation of clay soil is calculated. The models of belled pile and equal diameter pile were made to verify the deformation characteristics of soil under the electric explosion of the wire， and the bearing capacity and pullout resistance of the two piles were compared and analyzed. Based on the electrical and technological parameters of the high-voltage pulse bottom expanding technology model test， the first high-voltage pulse belled pile with a diameter of 0.8m was constructed in China， and the “irrigation-expansion” integrated construction method was developed.

Abstract:The electric blast shock wave has great application potential in increasing permeability and removing plugs of oil and gas reservoirs. In this paper, ANSYS/LS[CD*2]DYNA software is used to investigate the influencing factors of electric blast shock wave induced cracks through variation of the in situ stress, elastic modulus and tensile strength. The simulation results show that the in situ stress has a strong inhibitory effect on crack propagation. Under action of the two way isobaric in situ stress, the shape of the crack zone is circular, and with increase of the in situ stress, the fracture degree and fracture radius of the rock mass decrease gradually. Under action of the bi directional unequal compressive in situ stresses, as the difference between the horizontal principal stresses increases, the direction of crack propagation gradually changes from circular to elliptical, exhibiting the characteristic of extending along the direction of the maximum horizontal principal stress. The elastic modulus has important effect on crack initiation: with increase of the elastic modulus, the fracture degree and fracture radius of the rock mass increase. As the tensile strength increases, the fracture degree and fracture radius of the rock mass decrease.

Abstract:Shock wave is generated by the electro-hydraulic effect in high-voltage pulsed discharge technology, and local hole reaming is built in downhole. Finally, pedestal piles with different diameters are formed via cement injection. This paper describes the high-voltage pulse discharge technique about the pile forming mechanism by hole bottom reaming, the pile forming process and the effect on the pile diameter, studies the work of shock wave and vapor expansion pressure on pile diameter. The field experiment is carried out by using a newly introduced high-voltage pulse discharge device, the results show that the theoretical formula results are in good agreement with the experimental results.

Abstract:This page has set up a mechanics model and a optimized mathematics model of the working process for the YH-300A Pipe Hammer Using compound model method. Regarding the impaction energy as object number, we can make an optimizing design to the structure. This page also makes a calculation of impaction energy and impaction frequency of the original structure. After the optimize calculation, comparing to the original design the impaction energy has improve at least 19% and the impaction frequency has improve a little. At the same time, we make the finite element calculation to the piston of the YH-300A Pipe Hammer. After the finite element calculation, both the original design and the optimized design have proved the biggest stress located in the vent. And the stress on the impaction side is great. So we should use the finite element method to collate the intension of the body as we use the shock wave method to collate the intention. It can improve the shortage of the using of shock wave method in the intention calculation.