Overwetting soil solidified agent and method for solidifying soil

Abstract

The invention relates to an overwetting soil solidified agent and a method for solidifying soil; the overwetting soil solidified agent is solid CaCl2; the method for solidifying soil comprises the following steps: before construction, a lower supporting layer is checked and accepted according to quality acceptance standard, later, a middle line is restored; piles are arranged on a straight line section each 20 to 25m, and piles are arranged on a horizontal curve section each 10 to 10m, the positions of designed elevation and loose laying depth are marked on the edges at two sides of a road. On the whole testing section, the soil is laid one time, the road is statically pressed tow times by a road roller, the soil leveling is carried out by a land leveler according to the calculated loose laying depth; and then the material preparation is carried out; the using amount of CaCl2 is controlled by adopting a weight control method, according to the proportion of 6 percent to 8 percent of the solid CaCl2 and overwetting soil by mass fraction, by adopting a small loading transporting truck, the weight of the solidified agents on one truck is measured; according to aggregate using amount per liner meter obtained by calculation and tonnage of a material transporting truck, the stacking distance of the material in each truck is calculated, and the paving range of additives on one truck is controlled by a grid-making method; finally, pavement, blending, leveling, rolling compaction and initial maintenance are carried out.

Description

technical field [0001] The invention relates to an over-wet soil solidifying agent suitable for the treatment of over-wet clay foundations and a method for solidifying the soil, belonging to the technical field of civil engineering. Background technique [0002] Over-wet clay refers to the cohesive soil whose natural moisture content is not higher than the liquid limit, but much higher than the optimal moisture content, which cannot be directly compacted and rolled, and must be treated. There are roughly two definition methods, one is based on the consistency as the standard, and the other is based on the moisture content allowed to be compacted to the specified degree of compaction. The former thinks that when the consistency of the soil (w c =(w 1 -w) / (w 1 -w p ))w c ≤0.85 (sand) or w c ≤0.80 (clay) or w c ≤0.75 (silt), it can be regarded as over-wet soil, the latter is corresponding to the specified degree of compaction, when the compaction function is determined, ...

AI Technical Summary

Problems solved by technology

[0004] 1) High moisture content, forcible compaction is easy to form "spring soil"; even if it is turned over, it is difficult to meet the compaction standard of high-grade highway subgrade, and it is labor-intensive and time-consuming to take up land resources, delaying the construction period;

[0005] 2) Forcibly compact the over-wet soil. After the road is completed, under the action of driving load, it is very easy to cause problems such as large subsidence, cracking and roadbed instability on the over-wet soil subgrade road surface

Engineering practice shows that although the above materials can improve soil properties, make the treated soil have better compaction characteristics, and the soil strength has a greater increase, but their shortcomings are also obvious.

Mainly manifested in: (1) The water absorption of cement is poor, and the cost is high; p >20) The effect is not ideal; the construction process is more complicated, and the shrinkage is relatively large in the later stage of construction

(2) Quicklime fails quickly, the storage and transportation conditions are not easy to meet the requirements, and the construction time is long

(3) As for the fly ash improvement method, it has higher requirements on the source of materials (simultaneous mixing is required); the dust is relatively large during construction, and the required construction period is longer

(4) The price of NCS curing agent is relatively expensive, and it is difficult to popularize and promote engineering practice

We took the discarded carbide slag from Changzhou Acetylene Manufacturing Company and conducted a series of indoor preliminary tests. It shows that 1 ton of calcium carbide slag can chemically react with waste acid to extract 0.85 to 0.9 tons of calcium chloride, and the cost is about 330 yuan. / ton-400 yuan / ton, which is roughly equivalent to the average price of existing quicklime and cement, and it is entirely possible to meet the needs of the project

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