This study investigated the composite behavior of a GRS mass. It focused on the strength of a GRS mass, CIS in a GRS mass, the lateral deformation of a GRS wall with modular block facing, and the development of a rational design procedure for determining the required reinforcement strength of a GRS wall by considering both lateral stresses in the fill and lateral wall deformation of the wall system.
The following tasks were carried out:
Reviewed previous studies on composite behavior of a GRS mass and CIS in an unreinforced soil mass and a GRS mass.
Designed a GSGC test for investigating the composite behavior of a GRS mass and conducted five GSGC tests with well-controlled conditions and extensive instrumentation to monitor behavior under different reinforcement spacing, reinforcement strength, and confining pressure.
Developed an analytical model for the relationship between reinforcement strength and reinforcement spacing and derived an equation for calculating composite strength properties.
Developed a hand computation analytical model for simulation of CIS in a GRS mass.
Performed FE analyses to simulate the GSGC tests, generate additional data (with different confining pressures) for verifying the analytical models in this study, and investigate the behavior of GRS composites.
Verified the analytical models using measured data from the GSGC tests, relevant test data available in the literature, and FE analyses.
Developed an analytical model for predicting lateral movement of GRS walls with modular block facing.
The findings and conclusions of this study are as follows:
The results of the GSGC tests were consistent and appear very reliable. The tests provide direct observation of the behavior of a GRS mass as related to reinforcement strength and spacing. The tests also provide a better understanding of the composite behavior of a GRS mass and can be used for validation of analytical models in this study and other models of GRS structures in the future.
An equation describing the relative effects of reinforcement spacing and reinforcement strength was developed and verified. Based on the equation, the required reinforcement strength in a GRS wall can be determined, as can the composite strength properties and ultimate pressure carrying capacity of a GRS mass.
An analytical model for calculating lateral deformation of a GRS wall with modular block facing was developed and verified. The required tensile strength of reinforcement in design can be determined for a prescribed value of the maximum allowable lateral movement of a wall.
An analytical model for simulating compaction operation of a GRS mass was developed. The model allows CIS in the fill to be determined.
The presence of geosynthetic reinforcement has a tendency to suppress dilation of the surrounding soil and reduce the angle of dilation of the soil mass. The dilation behavior offers a new explanation of the reinforcing mechanism, and the angle of dilation provides a quantitative measure of the degree of reinforcing effect of a GRS mass.
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