Improvement method for soil structure of coastal dredger fills

Abstract

The invention relates to an improvement method for a soil structure of coastal dredger fills. The method is applied to a composite water solution of calcium nitrate and polyacrylamide, wherein the concentration of the calcium nitrate is 0.1-2.0g / L and the concentration of the polyacrylamide is 0.3-0.8g / L; the polyacrylamide is an anionic polyacrylamide solid with the molecular weight of 8-12 million. Aiming at the disadvantages of an existing improvement method for the soil structure of the coastal dredger fills, and aiming at improving a self-aggregate structure of the dredger fills, the formation of large aggregate particles of the dredger fills is promoted under the common effects of the calcium nitrate and a PAM (polyacrylamide) outer source additive through the bridging of PAM-Ca<2+>-soil particle positive ion bridge, so that the capillary porosity and the total porosity of the coastal dredger fills are increased.

Description

technical field [0001] The invention relates to a method for improving soil structure, in particular to a method for improving the soil structure of coastal dredging fill. Background technique [0002] Coastal dredging is a sedimentary soil formed by dredging the seabed mud from the offshore through hydraulic dredging. Because there is no soil forming process, and it is affected by seawater immersion for a long time, the soil has high salinity, strong sodium alkalinity, fine particles (mainly clay), large water holding capacity, high content of invalid pore water, and sticky texture. The characteristics of tightness, small porosity and permeability coefficient, and extremely long natural desalination process have seriously restricted the construction of cities and ecological environments in coastal land reclamation. Soil structure improvement is the necessary prerequisite and fundamental way to realize rapid desalination and alkali discharge of coastal dredger fill and to e...

AI Technical Summary

Problems solved by technology

The existing dredger fill soil structure improvement technology mainly uses exogenous additives, such as organic fertilizer, peat soil, and river sand, to physically mix with dredge fill soil in proportion to change the gradation composition of soil particles, thereby increasing the soil pore structure , due to the poor structure and tightness of the dredged fill soil, the mixing process is complex, the amount of work is large, the cost is high, and the soil quality is unevenly distributed after mixing, and the dominant flow is likely to be formed during the later leaching and desalination process, resulting in waste of water resources; in addition, Since the agglomeration structure of the dredger fill soil itself does not increase during this process, in the later stage of leaching and desalination process, the fine dredge fill soil particles are easy to move down continuously under the scouring of the water flow, and the soil body is discharged, resulting in the loss of the dredge fill soil. As a result, the water and fertilizer retention capacity of the improved soil is extremely poor