Design and construction method for improving expansive soil embankment by using phosphogypsum and microorganisms

Abstract

The invention relates to a design and construction method for improving an expansive soil embankment by using phosphogypsum and microorganisms, which is characterized by comprising the following steps: (1) putting Sporosarcina pasteurii into a culture medium to prepare a microbial solution, and mixing urea, calcium chloride and water to prepare a cementing solution; (2) uniformly mixing and stirring a material mixture, the microbial solution and water, adding the cementing solution, and mixing with water to prepare an improved material mixture; and (3) leveling and compacting the original ground, paving a geomembrane, the improved material mixture and a geogrid, paving the last layer of geomembrane on the top surface of the embankment after the embankment is paved, and then paving an embankment roadbed. The construction requirements of highway embankment projects, first-grade roads and other grades of roadbed projects can be met, and meanwhile solid waste phosphogypsum can be consumed.The cheap culture medium is adopted for microbial culture, the use cost is reduced, the ardealite improved through microorganisms can achieve solidification of harmful elements, and pollution to theenvironment is reduced.

Description

technical field [0001] The invention relates to the field of roadbed engineering, in particular to a design and construction method for improving expansive soil embankments by using phosphogypsum and microorganisms. Background technique [0002] Expansive soil contains rich clay minerals such as montmorillonite and illite, which have the characteristics of swelling when it encounters water and shrinking when it loses water. After the expansive soil embankment is flooded, expansive diseases will occur, resulting in cracking of the pavement. The traditional methods for the disposal of expansive soil embankments mostly use engineering measures such as cement improvement, lime improvement, and curing agent improvement. To a certain extent, these methods can appropriately increase the bearing capacity of the subgrade, improve the expansibility, and reduce the risk of pavement cracking, but there are also problems of uneven settlement of the subgrade due to improvement failure. ...

AI Technical Summary

Problems solved by technology

To a certain extent, these methods can appropriately increase the bearing capacity of the roadbed, improve the expansibility, and reduce the risk of pavement cracking, but there are also diseases of uneven settlement of the roadbed caused by improvement failures.