Experimental, theoretical and finite element analysis of a reinforced earth retaining wall including compaction and construction procedures
This thesis is concerned with an experimental and theoretical study of the behaviour of a reinforced earth retaining wall built on a rigid foundation, during and after construction with special attention paid to the effect of the compaction process. The theory and development of reinforced earth, four case histories, and tests on full scale models and small scale models related to the effects of compaction and current design methods have been reviewed with comments. The research work is tackled on two fronts: - Experimental model study. - Theoretical studies. 1) Experimental model study The model study, a three dimensional model, simulates a vertical reinforced earth retaining wall of height 6.0m with a model scale `10'. The model comprises an open fronted wooden box 1300mm long, 900mm wide and 700mm high, and the box contains the wall retaining 1200Kg of sand reinforced with aluminium foil strips 0.1mm thick attached to perspex facing panels of 150 x 150 x 18mm each. The sand bed in the model was formed using a sand spreader, dust extractor machine and a vibratory compaction device simulating the compaction plant in the field. Sixty six strain gauges, sixteen miniature pressure cells, which were developed and calibrated completely in the laboratory, and eight LVDTs were used to monitor the behaviour of the wall before, during and after compaction, under various uniform and variable compaction lengths and different methods of construction. Two methods of calibrating the density in the models were established, viz. temporary metal metal cylinders and permanent perspex cylinders. 2) Theoretical studies These were divided into two sections as follows: a - Theoretical study of compaction. b - Finite element method.