Performance Evaluation of Geocell Reinforced Machine Foundation Beds

Abstract

The present chapter describes the results of large-scale field vibration tests and cyclic plate load tests conducted on geosynthetics reinforced soil beds. A series of vertical mode block resonance tests are conducted over a rigid concrete footing resting on different reinforced soil conditions. The tests are performed in a test pit of size 2 m × 2 m × 0.5 m using a concrete footing of size 0.6 m × 0.6 m × 0.5 m. Four different conditions, namely unreinforced, single-layer geogrid reinforced, two-layer geogrid reinforced and geocell reinforced conditions were considered. The tests are performed under six different dynamic force levels using a Lazen-type mechanical oscillator. In total, 38 number of field tests are conducted. The dynamic response is studied in terms of reduction in resonant amplitude, peak particle velocity (PPV) and improvement in dynamic properties of the soil. Experimental results revealed that the displacement amplitude of vibration significantly reduced in the presence of geosynthetics. The maximum reduction is observed in the presence of geocell reinforcement as compared to other conditions. In the presence of geocell reinforcement, the resonant amplitude is decreased by 61% and the natural frequency of the soil system is increased by 1.38 times as compared to the unreinforced condition. In addition, the geocell reinforcement found to reduce the PPV by 48% at a distance of 0.5 m from the footing face. The elastic uniform compression of the foundation bed is improved by 91% in the presence of geocell reinforcement. From the cyclic plate load test results, four times improvement in natural frequency of the foundation soil system and 92% reduction in amplitude of the vibration were observed by the combined utilization of geocell and geogrid.