Expansive soil

a commonly distributed clay

is unsuitable for direct engineering applications. This study proposes a method to produce foam lightweight soil from expansive soil

effectively mitigating its expansive properties. The physical and mechanical properties of expansive soil-based lightweight soil (E-LS) were systematically investigated under varying water-solid ratios

wet densities

and expansive soil contents

using tests for flow value test

drying shrinkage test

pH test

and compressive strength test. An orthogonal experiment was conducted to quantify the influence of these factors on unconfined compressive strength (q)

leading to the development of a strength determination method. The results show that the preparation of E-LS modifies the expansive soil structure

completely eliminating its expansiveness. Compressive strength of E-LS increases with both wet density and curing age. For expansive soil contents ranging from 30% to 60%

the unconfined compressive strength at 28 days () varied from 0.21 MPa to 1.58 MPa. Specifically

for E-LS with 50% expansive soil content

a water-to-solid ratio of 0.8

and a wet density of 900 kg/m

the reached 0.92 MPa

meeting the requirements for embankment construction. The factors affecting compressive strength are ranked as expansive soil content > wet density > water-solid ratio

and a predictive model for E-LS strength was developed. E-LS exhibits the capability to fulfill diverse embankment filling requirements in engineering applications

while demonstrating distinct advantages including expansive property mitigation

compaction-free implementation

and construction efficiency

thereby presenting significant potential for practical engineering deployment.