Effect of shearing speed on the shear strength parameters of remoulded lateritic soil / Ahmad Paridz Abdullah

The shear strength is an important part in soil engineering. It is the property, which provides the supporóng ability and bearing capacity of soil. Shearing speed or rate of loading applied during the process shearing of soil sample is on the basis of value recommended by British Standard (BS). Effect of speed should be curiously taken into consideration especially clay soil as it nas a very low permeability with respect to its finer size fraction. The lower the penneabitity the longer the time needed for the pore pressure equalization (95%) of pore water pressure equalization as recommended by BS. Shearing speed can be expressed as the deformation of soil during shearing per time to failure. British Standard has Umited the deformation as maximum as 25% especially for plastic deformation whilst the time to failure is given by the primary consotidation time (tioo) multiply by the coëfficiënt of side drain as derived by Bishop and Hakel, 1962 and Blight (1963). BS have outlined the minimum time to failure for any type of soil as 2 hours. If any soil yields time to failure base on consotidation time is less than 2 hours, then the minimum time of 2 hours should be taken in determining the shearing speed. It should be noted that the time to failure outlined by BS is due to the testing conducted on non-Malaysian soil. Currently Malaysian engineers have questioned the validity of time to failure on Malaysian soil and asked for slower speed, as the behavior of soil is different from one place to another.