Composition of the ground in soft ground reinforcement method

摘要

The present invention relates to a method of forming an underground reinforcement body in a soft ground, wherein a soft ground is perforated to a desired depth while a perforated rod is installed by using a perforated rod mounted on a perforator and having an excavating bit at its lower end, (A) spraying high-pressure water or high-pressure water accompanied by compressed air laterally through the formed high-pressure water / compressed-air injection nozzle to cut or loosen the surrounding ground in advance; When the piercing / cutting / loosening of the ground is completed up to the target depth, the supply of the piercing water, the compressed air and the high-pressure water is stopped, the piercing rod is rotated at a low speed, And a step (B) of injecting and curing a low-flow cement mortar underground reinforcement in a lateral or side-down manner in a low-pressure charging manner to form a columnar underground reinforcement in the ground. The underground reinforcement composition By providing a method, During the drilling operation, high-pressure water or high-pressure water accompanied by compressed air is sprayed through a high-pressure water / compressed-air injection nozzle formed in the perforated rod to cut or loosen the surrounding ground in advance so that a low-fluidity cement mortar Facilitating the injection, thereby creating a condition capable of being injected in a large volume, In the case of high pressure water injection with compressed air, the cement mortar stiffener is displaced to the ground during the injection of the low - flow cement mortar. Thereby preventing the problem of environmental pollution caused by the vannithose containing a large amount of cement component and preventing deterioration of the quality of the composition reinforcing material due to deviation of the cement component, In addition, in order to secure the verticality of the underground reinforcement formed by imparting the rotation function to the boring rod during the injection operation of the low fluidity cement mortar underground reinforcement, the rotation speed of the injection pipe is specified, The injection volume is connected to the injection tube draw rate per unit time to allow continuous, mechanized and quantitative work.