CN101560760B - Construction method for fast concreting and dredging and filling ultra-fine earth foundation - Google Patents

Abstract

The invention relates to a construction method, in particular to a construction method for fast concreting and dredging and filling ultra-fine grained soil foundation. The method comprises the following steps of: arranging a well-point pipe on the surface of a consolidated foundation area and starting a vacuum pump for forced water discharging; arranging calcium oxide on the surface of the consolidated foundation area, mixing with an excavator, fully blending within a treatment deep range, leveling the surface with a bulldozer after the completion of the mixing, stewing materials for 24 hoursuntil the calcium oxide is fully decomposed, utilizing the physical and chemical reactions between the calcium oxide and a soil body to increase the weight of the soil body and generate self-weight concreting; starting an impact rolling and vibration rolling equipment to generate displacement, distortion and shearing to the soil grains, thus compacting the deep layer of the soil body together withthe transmission of a shock wave and quickening the sedimentation and consolidation of the soil body within the treatment range. The foundation carrying capacity can reach 80 to 120 kPa after being treated, thus solving the problem that personnel and equipment are operating at the site in a short time, and the technique is mature, and the construction efficiency is high.

Description

The job practices of fast concreting and dredging and filling ultra-fine earth foundation

Technical field:

The present invention relates to construction techniques, particularly a kind of job practices of fast concreting and dredging and filling ultra-fine earth foundation.

Background technology:

The reclaiming land around sea engineering is faced with two subject matters, and one is the barged-in fill problem of materials, and one is the reinforcing problem of barged-in fill ground.From technical standpoint; optimal hydraulic reclamation material is a sand; but since construction work at present in a large number with sand and environmental protection and water conservancy security needs restriction or forbid adopting sand, so sand costs an arm and a leg and shortage, be difficult to satisfy the needs of reclaiming land around sea engineering material.Main at present silt soil banketing of adopting hydraulic reclamation as reclaiming land around sea.But it is should the soil water content high, be in flow regime, its compressibilty is big, intensity and bearing capacity are extremely low, especially the hydraulic reclamation pipeline exit to the terminal soil body particle in hydraulic reclamation zone from the coarse to fine, bottom to top layer soil body particle presents particle distribution characteristics from the coarse to fine, particle diameter≤0.005mm, organic content is greater than gross mass 7.5%, and bearing capacity of foundation soil can't satisfy the condition that personnel, equipment march into the arena.Routine is to adopt the fixed method of nature, promptly needs the time about 2-3 the water in the super fine grained soils of hydraulic reclamation could be got rid of, if method such as fill out is changed in employing then cost is very high.Therefore, finishing the place at short notice and solidify, solve the construction equipment construction of marching into the arena, is present reclaiming land around sea urgent problem.

Summary of the invention:

The present invention is intended to address the above problem, and a kind of to have a speed of application fast and provide, and the duration is short, reduces construction cost, handles the job practices that the darker vacuum of the degree of depth is forced the fast concreting and dredging and filling ultra-fine earth foundation of precipitation and the fixed associating impact-rolling of quicklime.

The technical solution used in the present invention is: a kind of job practices of fast concreting and dredging and filling ultra-fine earth foundation, undertaken by following step:

(1) be reinforced the well location of foundation region surface, carrying out the well point pipe and lay by the design of dewatering construction layout plan, well point pipe depth of placement 8-18m, the well point pipe connects vacuum pump by water header, starts the vacuum pump draining;

(2) lower 70% when above when water content, dismounting well point pipe, arrange quicklime being reinforced on the foundation region ground then, mix and stir with excavator, when mixing and stirring ultra-fine grain soil layer is translated into the end, the limit flange is mixed, the artificial quicklime admixture ratio of controlling guarantees to handle mixing evenly in the depth bounds, turns at least twice, turn and with bulldozer it is flattened after finishing, stewing material 24 hours fully makes quicklime clear up, and utilizes quicklime and soil body generation physics, chemical reaction, the honeycomb structure that super fine grained soils forms mixes and stirs in quicklime curing and produces cohesion in the process, form jelling structure, under less construction disturbance, the soil body obtains densification and gluing, the severe of the soil body is increased, and the generation deadweight is fixed;

(3) be reinforced layout impact-rolling and vibroroller cmpacting machinery on the foundation region ground, start impact-rolling equipment and vibroroller cmpacting equipment, make between the soil particle and be subjected to displacement, be out of shape and shear, thereby make soil body deep layer along with shock Wave obtains compacting, the sedimentation of quickening the soil body in the process range is fixed, makes bearing capacity of foundation soil reach 80-120kPa.

The know-why of the technical program is: by the vacuum forced drainage pore water in the soil body is discharged, ground generation sedimentation, fixed gradually, mix quicklime in good time and solidify, the honeycomb structure that super fine grained soils is formed mixes and stirs in quicklime curing and produces cohesion in the process, forms jelling structure, under less construction disturbance, the soil body obtains densification and gluing, and the severe of the soil body is increased, and the generation deadweight is fixed; After quicklime is cleared up, adopt impact-rolling to make between the soil particle and be subjected to displacement, be out of shape and shear, thereby make soil body deep layer along with shock Wave obtains compacting.

Compared with prior art, advantage of the present invention and effect are: by organic optimum organization that vacuum forced drainage, quicklime solidify, shock and vibration roll, can make the bearing capacity of foundation soil after the processing reach 80-120kPa, solve the problem that people and equipment ground on the scene carry out operation in the short time.Having saved cost and duration greatly, obtained good economic benefit, is a breakthrough to the ultra-fine grain of original hydraulic reclamation soil base treatment process.Be specially adapted to mud matter silty clay, especially particle diameter≤0.005mm that hydraulic reclamation forms, organic content greater than the mud matter silty clay stratum construction of gross mass 7.5% and blast-filled ground and border on the sea, wait the construction to the tight engineering of construction period such as ultra-fine grain soil site, the road of marching into the arena near a river recently.This method technical maturity, used device is few, speed of application is fast, and the reinforcing expense is low, and is simple to operation, the efficiency of construction height, and ground stabilization is effective.

The specific embodiment:

Below in conjunction with embodiment in detail the present invention is described in detail.

A kind of job practices of fast concreting and dredging and filling ultra-fine earth foundation, undertaken by following step:

(1) is being reinforced the well location of foundation region surface, carrying out the well point pipe and lay, adopting double light well point, outside pipe range 6.0m, inboard pipe range 4.0m, spacing 2.0m by the design of dewatering construction layout plan.The place is inner adopts single light well point, adopts shallow, the deep layer pipe precipitation alternate layout that combines, filter pipe length 1m, well point tube pitch 4.0m, lying pipe array pitch 4.0m.Well point pipe depth of placement 8-18m will

Lying pipe and

The vertical drainage pipe is put according to the design well location, adopts supporting junction block to connect lying pipe.Burying underground of well point pipe adopts giant water to rush in row, punching pressure 0.1MPa.Start high-pressure hydraulic pump soil is dashed pine, the limit trimming is heavy, and punching hole diameter is

To guarantee that well casing has the sand filter blanket of certain thickness (about 130mm) on every side.When punching reaches projected depth, lower hydraulic pressure rapidly.Behind the pore-forming, the well point pipe that has twined filter cloth is dropped into well, the well point pipe adopts the PVC plastic pipe of diameter 36mm.Filtrate is selected the gravel of 3-15mm, fills out and irritates evenly, and be filled to upward 1.5m of chimney filter top.Dry vacuum pump is arranged on the harder ground, periphery, place, adopts the steel wire rubber leather hose to be connected dry vacuum pump and lying pipe, and lying pipe is connected through hard plastic tube with the well point pipe, with plastic sheeting and putty union is sealed.The well point installation draw water unit be connected lying pipe after seal upper space between well point pipe and hole wall with clay, and to check the sealing between each union, with anti-gas-leak.The well point pipe connects vacuum pump by water header, starts the vacuum pump draining.

(2) lower 70% when above when water content, remove inner well point connected system, adopt the special jig of excavator cooperation that vertical well point pipe is hung and pull out dismounting.Arrange the quality quicklime that meets the requirements of the standard being reinforced on the foundation region ground then, the quicklime that mixes 8-15% mixes and stirs with excavator, when mixing and stirring ultra-fine grain soil layer is translated into the end, the limit flange is mixed, the artificial quicklime admixture ratio of controlling guarantees to handle mixing evenly in the depth bounds, turns at least twice, turn and with bulldozer it is flattened after finishing, precision is controlled in the 100mm.Stewing material 24 hours, quicklime is cleared up, utilize quicklime and soil body generation physics, chemical reaction, the honeycomb structure that super fine grained soils forms mixes and stirs in quicklime curing and produces cohesion in the process, form jelling structure, under less construction disturbance, the soil body obtains densification and gluing, the severe of the soil body is increased, and the generation deadweight is fixed.

(3) be reinforced layout impact-rolling and vibroroller cmpacting machinery on the foundation region ground, adopting impact road roller that it is rolled, rolling speed is controlled at 12-15Km/h, rolls 10 times, and settling amount is controlled at 100-150mm.After finishing, adopt impact-rolling 12 tons of vibratory rollers to carry out vibroroller cmpacting 2 times, voltage stabilizing 1 time, and it is further closely knit that the 500mm thick soil body in top layer is obtained.Make between the soil particle to be subjected to displacement, to be out of shape and shear, thereby make soil body deep layer along with shock Wave obtains compacting, the sedimentation of quickening the soil body in the process range is fixed, makes bearing capacity of foundation soil reach 80-120kPa.

Claims (1)

1. the job practices of a fast concreting and dredging and filling ultra-fine earth foundation, undertaken by following step:

(1) be reinforced the well location of foundation region surface, carrying out the well point pipe and lay by the design of dewatering construction layout plan, well point pipe depth of placement 8-18m, the well point pipe connects vacuum pump by water header, starts the vacuum pump draining;

(2) lower 70% when above when water content, dismounting well point pipe, arrange quicklime being reinforced on the foundation region ground then, mix and stir with excavator, when mixing and stirring ultra-fine grain soil layer is translated into the end, the limit flange is mixed, the artificial quicklime admixture ratio of controlling guarantees to handle mixing evenly in the depth bounds, turns at least twice, turn and with bulldozer it is flattened after finishing, stewing material 24 hours fully makes quicklime clear up, and utilizes quicklime and soil body generation physics, chemical reaction, the honeycomb structure that super fine grained soils forms mixes and stirs in quicklime curing and produces cohesion in the process, form jelling structure, under less construction disturbance, the soil body obtains densification and gluing, the severe of the soil body is increased, and the generation deadweight is fixed;

(3) be reinforced layout impact-rolling and vibroroller cmpacting machinery on the foundation region ground, start impact-rolling equipment and vibroroller cmpacting equipment, make between the soil particle and be subjected to displacement, be out of shape and shear, thereby make soil body deep layer along with shock Wave obtains compacting, the sedimentation of quickening the soil body in the process range is fixed, makes bearing capacity of foundation soil reach 80-120kPa.