HOUSING CONSTRUCTION ON INCLINED CUTS

In order to meet the housing needs with the constraints of meager space available for development, new construction methodology is to be evolved. Soil Nailing is one of the emerging technologies which can help civil engineers for underground construction, slope stability, housing construction on inclined or vertical cuts etc. The literature available on this techniques reveals findings based on experimental and empirical studies only. The empirical studies made by various investigators are mostly made by assuming circular, parabolic and straight line rupture surfaces only. In the present study an attempt has been made to develop design of nailed open cuts by assuming log-spiral rupture surface. In the study the tensile force in the nail material has been determined with strength property of nail material. All the possible variables. e.g. nail angle, nail length, nail’s structural geometry, nail’s spacing (horizontal & vertical), method of nail installation, type of loading, nail materials etc have been incorporated in the study. It has been found that the optimum nail angle with the perpendicular to the face and excavation lies between 0 to 10(degree) The optimum length is between 0.6 to 0.9 H, H being the height of cut. Grouted nails are found to exhibit more factor of safety as compared to driven nails. The plastic modulus of the nail material also plays an important role; higher the plastic modulus, more the factor of safety. For construction at the inclined cuts, design charts have also been developed in the present study.