Dry and dense resonance method for reinforcing soft soil foundation of new hydraulic-fill sand

Abstract

The invention relates to a dry and dense resonance method for reinforcing a soft soil foundation of new hydraulic-fill sand. The method is suitable for reinforcing the soft soil foundation of the new large-area hydraulic-fill sand quickly. The method comprises the following steps of: 1, establishing resonance equipment; 2, distributing points in a constructional area; 3, dewatering in the constructional area, namely dewatering in a mode of combining light well-point dewatering with the water pumping of a vibrator, and performing resonance by using the vibrator after the water level of underground water is reduced to a certain range; 4, performing vibration retention for the first time, namely performing the vibration retention after the vibrator reaches the required depth; 5, performing the vibration retention stage by stage, namely lifting the vibrator by 0.4 to 0.6 meter to perform the vibration retention for the second time after the reinforced depth is reached and the first-time vibration retention is performed, and performing the vibration retention stage by stage in a mode of lifting the vibrator by 0.4 to 0.6 meter until the vibrator is lifted to the ground surface; and 6, performing counterpoint on resonance points, namely during resonance, after a group of double-end or three-end resonance is completed, guiding double-end or three-end resonance equipment to the other group of point positions which need to be resonated by using a crane to perform the next group of resonance. The dry and dense resonance method has a good sealing effect, and the problem of performingresonant construction on sludge interlayers is solved.

Description

technical field [0001] The invention relates to a new dredger filling sand weak foundation reinforcement method. It is suitable for rapid reinforcement treatment of large-area newly dredged sand and weak foundation. It belongs to the technical field of foundation treatment. Background technique [0002] At present, with the rapid development of coastal areas, tidal flats and reclamation methods are used to solve the shortage of industrial land. For the treatment of large-area dredged sand and such soil with a thickness of dredged sand layer below 6.0m, the "resonance method without filler" can be applied at present. Through this method, the effect is obvious, and the treatment depth can basically meet the design requirements. The principle of this construction method is to use the excitation frequency of the vibrator to pass a certain water flushing pressure (generally control the water flushing pressure at 0.2Mpa). 0.5m for 15-20 seconds), so that the particles of the dr...

AI Technical Summary

Problems solved by technology

However, in the actual construction process, although the sand particles are rearranged under the excitation frequency of the vibro-impactor, due to the high water content of the soil during the resonance process, a large amount of free water in the dredged sand layer and The water flushing pressure at the time of resonance affects the density of the arrangement of the sand grain layer, so the effect after treatment by this method is generally not very good, and the characteristic value of the bearing capacity of the foundation is ≤80KPa / m2

The main reason is the high water content of the new dredged sand itself, coupled with the water flushing pressure during the resonance process, the water content in the area to be reinforced is further aggravated, and its overflow cannot be controlled, so it is difficult to achieve the ideal compaction effect in the resonance reinforcement area

[0003] At the same time, the deadliest thing about the current "filler-free vibrating method" is that the reinforcement area has a high requirement for sand content, especially during the resonance construction period, there must be no mud upturning, and no filler can be carried out if the mud is found to surge up (even if grass roots are found). resonance

Because vibrating without filler pays attention to the rearrangement of sand particles, if there is mud, the mud will be mixed with sand, and the mud concentration in the resonance hole will greatly affect the rearrangement of sand particles, which will seriously cause mud retaining walls, and the resonance area will become a hole. destroyed the soil structure

[0004] To sum up, although the reinforcement depth of “vibration without filler” is controllable (it can reach the required depth), due to the strict requirements on the new dredged sand, and the water flushing pressure formed by groundwater plus resonance, the reinforcement area contains The amount of water is too high to achieve real rearrangement of sand grains, therefore, the bearing capacity of the reinforced foundation cannot be further improved

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