CONTROL OF LIQUEFACTION USING REINFORCED EARTH DRAIN

Abstract

One of the major causes of catastrophic damage to engineering structures during earthquakes has been liquefaction of saturated cohesionless soil deposits. Due to this, the foundations of structures may undergo substantial movements causing severe damage resulting into heavy loss of lives .and property. The analysis of liquefaction is not yet well developed. As such, there is an urgent need for research on control of liquefaction. The proposed investigation--aims-to.~study__the performance of reinforced vertical curtain drains filled with free draining filter material for the control of liquefaction. In the proposed investigation, fine SOLANI river sand deposited in a test tank (1.05 m x 0.60 m x o.40 m high) and subjected to sinusoidal horizontal vibrations has been employed. Vertical curtain drains formed by pouring gravel enclosed in nylon clothing have been employed for control of liquefaction. Pore pressures have been monitored by using both strain gauge .mounted diaphragm type of pickups and by manometer. type of pickups. Suitable arrangements have been designed and developed so that the pore pressure measuring devices do not obstruct the natural behaviour of the soil deposit. The SOLANI sand is poured into the tank filled with water to obtain a loose deposit of sand. Then the tank is vibrated at desired frequency, acceleration levels and durations. The pore pressure developed are recorded. The results of the experimental investigation have been presented in terms of dimensionless parameters to make the presentation more meaningful and independent of units.