Since the last century80After our country began to use gravel filler to reinforce the cohesive soil foundation in the early decade, a variety of gravel pile construction technologies have appeared successively, such as hammer, dry extrusion, dry vibration, submerged tube, vibroflotation and so on. The diameter of pile is difficult to exceed in traditional immersed tube gravel pile technology800mm, pile length shall not exceed20m. In recent years, our company has done a number of gravel pile foundation treatment projects, accumulated more valuable experience, and according to the needs of the actual project, the traditional gravel pile technology has done a lot of improvements, and finally successfully developed a large diameter vibrating immersed tube gravel pile.

Compared with the traditionalprocess, our large diameterImmersed tubeGravel pile newprocessThe main advantages are as follows:

(1) Large pile frame, high power:Our gravel pile is largePile frame (see figure1) carrying power400/500kWThe high energy vibration hammer, gravel pile into pile diameter up to1200mm, pile length can exceed30mSo that the effective diameter and depth of gravel pile have a great breakthrough.

(2) Saving time limit:Under the same displacement rate, the new process can greatly reduce the total number of piles, so as to effectively save the construction period.

(3) Reliable discharge:In some soft soil or liquefiable silt soil, due to the pressure of water and soil on the bottom of the pile, the valve of the pipe boot can not be opened, and discharging is difficult. In this respect, we have accumulated rich experience, and can improve the equipment according to the actual situation to ensure smooth discharge.

(4) Safe feeding mode:The traditional feeding method is to use steel rope to suspend the hopper, because the hopper is not fixed, there are great safety risks. The free sloshing of the hopper also greatly affects the feeding efficiency and delays the construction period. In view of this defect, our gravel pile equipment adopts the forward track feeding method (see figure)2), the lifting hopper is fixed on the front track, eliminating the hidden danger of safety, improve the safety, but also improve the construction efficiency.

(5) Intelligent control system:Our company's gravel pile construction equipment has introduced an intelligent control system, which can real-time monitor the vibration hammer current, the amount of cutting material, sink pipe and pipe drawing speed and other key parameters, real-time display of pile depth-- Current-time curve to realize intelligent construction of crushed stone pile and ensure the accuracy of construction parameters.

(6) Wide application scope:Our gravel pile equipment can not only be appliedIt can be applied to land foundation treatment and water foundation treatment(Using our thousand-ton engineering ship as carrier), to meet more and more water foundation treatment projects.

The above is the introduction of our new technology of large-diameter vibrating immersed tube gravel pile. At the same time, our company will continue to improve the technology according to different reinforcement needs, soil characteristics and construction environment, so as to meet more and more foundation treatment requirements.

At present, our company has dozens of gravel pile construction equipment has been put into use, but also trained a reliable, professional construction team, is playing a role in more and more infrastructure projects, contributions..

figure1  Large pile frame, high power gravel pile equipment

figure2  Improved large diameter immersed tube gravel pile equipment