The Consolid System In The Application Of Soft Clay Engineering

Soft soil is the common unfavorable geological in the engineering construction, it is a special class of clay which has the nature of the high moisture content, high porosity and high compressibility etc. Soft soil is often called "spring soil" for difficultly to be compacted. In the construction of practical engineering, even though after dealing with soft soil by reinforcement method, it will be the hidden trouble of the engineering construction by the possibility of watering burst again. Therefore, it is fundamental to solve the problem of soft soil that how to reduce or even prevent soft clay from absorbing water around the soil, it is also the starting point that we study the soft soil in countryside highway.The methods of soft soil is roughly divided into two categories: firstly, conventional methods; the second, method of soil stabilizer. There are many kinds of conventional approach method and the effect is obvious, but it generally does not apply to rural road because of the high cost. The price of soil stabilizer method are relatively cheap and easy construction, but there are still insufficient in different areas of soil in engineering application. In the soil engineering, the packing of the roadbed is almost soil and a small amount of stone(gravel), the key factors of roadbed appearing instability or "spring" is the soil, the root cause is that the soil absorb water, expand, and eventually appear the status of soft, namely "spring soil”. Therefore, the key to dealing with soft soil in this paper is how to solve the clay swell and make the soil stable in the water. Dealing soft soil with soil stabilizer can be modified "hydratable " and not afraid of water erosion. The soft soil after stable treatment stability increased significantly, but the intensity decreased significantly. That is not enough to be used in engineering. Therefore, the key that soil stabilizer method to engineering application is improving the intensity of soil and not hydration, high strength on the basis of soil water stability enhancement.This paper takes soft soil from "Yang ren avenue project" at Ren he community, Yan an town as the research object. Use consolid as the stability agent to governance soft soil to improve hydration resistance of soft soil; at the same time by adding a small amount of inorganic cementitious materials(cement, lime) and grading macadam to improve the strength of the soft soil.Test results show that:(1) In imitation of subgrade incomplete immersion test, the samples added 2% consolid of can prevent infiltrates surface from rising, expanding, not damaged, and guarantee the stability of the bottom. In addition, the consolid can improve the ability of resisting dry shrinkage of soft soil.(2) Consolid combined with cement, lime can improve water stability of soft clay. At the same time, the shear strength and compressive strength is also improved. Soft soil samples of cohesion, angle of internal friction, compressive strength reach maximum value, when adding amount of gelled material was 7%, the percentage of lime replacing cement was 40%. And the total gelled material dosage is the key to affect the strength. In the process of bubble water, the samples not adding consolid lose bearing capacity after 30 minutes, the samples adding consolid is in good condition and strength increase significantly.(3) Consolid combined with graded crushed stone can effectively restrain the expansion of the soft soil, CBR is worth to effective increasing, Compared with the samples without consolid, expansion amount decreased by 22%~25%, CBR value reached the maximum when the quality ratio of soft soil and gravel is 7:3. After bubble water contrast, the samples not adding consolid disintegrat gradually, collapse. the samples adding consolid did not appear expansion, cracking. It guarantees the rock embedded squeeze and keep the strength of the sample effectively.(4) Combined with test road, the rebound deflection of the soft soil and gravel soil road after consolid treatment gradually decline as the growth of the age, compared with the early, declining significantly. The compaction is also far bigger than the design requirements of the 4th-Grade Highway.