Walnut Shell Filter Tube And Its Application Research Of Soil Improvement In Horizontal Directional Hole

Soil salinization has seriously restricted the development of the economy. Usually the way to improve saline alkali soil is open ditch and subsurface drainage. But Excavation is a big damage to the surface and the ubsurface drainage is limited in depth. Other methods such as planting alkali plants, take a long time to achieve.This article relies on the project Jizhong plain typical salinization of soil region hydrogeological survey of Center for Hydrogeology and Environmental Geology China Geological. The project explores long-distance horizontal wells to increase the amount of water, to reduce the groundwater evaporation, and finally find a method to improve the saline land.On the base of previous gravel filter research, explore a new walnut gravel filters which is bigger in permeability coefficient and cheaper. Choose nontoxic adhesive according to four factors and three levels orthogonal experiment test, making sample, measuring compressive strength and shear strength. Make small filter to observe the shear strength and the degree of crack when under hard environmental conditions.This project selects brittle PVC-U pipes and walnut gravel filter pipe. On the basis of previous studies, analysis the complex pullback pipe force model of trenchless horizontal directional drilling, combined with the stress calculations based on actual construction trajectory parameters of Cangzhou project. Propose practical suggestions.For the shallow aquifer of Cangzhou formations, consider using a more energy-efficient way to extract groundwater by siphon jetting. Use atmospheric pressure to collect groundwater, and control automatically.Finally, according to the actual field engineering situation, draws the following conclusions:1.Walnut gravel filter pipe is under great bending stress in bending segment, and PVC-U drainage pipe comes in the back near the tail section, you can reduce the drainage pipe diameter or increase the radius of curvature of the curved section method to drag pipes back smoothly.2. Walnut gravel has lower density. According to the pumping tests, the water amount of walnut gravel drainage pipe is close to 1.5 times of the packet network drainage pipes, the effection is obvious.3. Siphon jet pumping system works well in shallow aquifer, also is energy saving and environmental protection, which helps to achieve large-scale pumping.4. The water flow field of horizontal wells pumping is a disk. The range of precipitation is bigger than the shaft, more easier to reduce the regional groundwater level, better improving the saline soil.