Cyclic settlement behavior of strip footings resting on reinforced layered sand slope

The paper presents a study of the behavior of model strip footings supported on a loose sandy slope and subjected to both monotonic and cyclic loads. The effects of the partial replacement of a compacted sand layer and the inclusion of geosynthetic reinforcement were investigated. Different combinations of the initial monotonic loads and the amplitude of cyclic loads were chosen to simulate structures in which loads change cyclically such as machine foundations. The affecting factors including the location of footing relative to the slope crest, the frequency of the cyclic load and the number of load cycles were studied. The cumulative cyclic settlement of the model footing supported on a loose sandy slope, un-reinforced and reinforced replaced sand deposits overlying the loose slope were obtained and compared. Test results indicate that the inclusion of soil reinforcement in the replaced sand not only significantly increases the stability of the sandy slope itself but also decreases much both the monotonic and cumulative cyclic settlements leading to an economic design of the footings. However, the efficiency of the sand-geogrid systems depends on the properties of the cyclic load and the location of the footing relative to the slope crest. Based on the test results, the variation of cumulative settlements with different parameters is presented and discussed

effect of deep excavation-induced lateral soil movements on the behavior of strip footing supported on reinforced sand

This paper presents the results of laboratory model tests on the influence of deep excavation-induced lateral soil movements on the behavior of a model strip footing adjacent to the excavation and supported on reinforced granular soil. Initially, the response of the strip footings supported on un-reinforced sand and subjected to vertical loads [which were constant during the test] due to adjacent deep excavation-induced lateral soil movement were obtained. Then, the effects of the inclusion of geosynthetic reinforcement in supporting soil on the model footing behavior under the same conditions were investigated. The studied factors include the value of the sustained footing loads, the location of footing relative to the excavation, the affected depth of soil due to deep excavation, and the relative density of sand. Test results indicate that the inclusion of soil reinforcement in the supporting sand significantly decreases both vertical settlements and the tilts of the footings due to the nearby excavation. However, the improvements in the footing behavior were found to be very dependent on the location of the footing relative to excavation. Based on the test results, the variation of the footing measured vertical settlements with different parameters are presented and discussed