LRFD Driven Pile Design
LRFD Driven Pile Design
(OP)
thread256-229716: AASHTO LRFD Driven Pile Estimated Length
In reference to the above thread, if we use phi(static)=0.4 to determine the length of the pile and during construction use dynamic testing phi(dyn) =0.65 the production pile lengths will be one third shorter and will invite claims from the contractor because the change in quantities is greater than 25%. This is the standard practice for the state agencies we work for. Furthermore, if we use phi(dyn) = 0.65 and depending on the psi load factor we use to calculate the factored load the equivalent factor of safety is equal to 2.0 which is similar to the factor of safety we generally use in ASD pile design with dynamic testing. If this is not the case what is the relationship between phi(dyn) and phi(stat)?
In reference to the above thread, if we use phi(static)=0.4 to determine the length of the pile and during construction use dynamic testing phi(dyn) =0.65 the production pile lengths will be one third shorter and will invite claims from the contractor because the change in quantities is greater than 25%. This is the standard practice for the state agencies we work for. Furthermore, if we use phi(dyn) = 0.65 and depending on the psi load factor we use to calculate the factored load the equivalent factor of safety is equal to 2.0 which is similar to the factor of safety we generally use in ASD pile design with dynamic testing. If this is not the case what is the relationship between phi(dyn) and phi(stat)?





RE: LRFD Driven Pile Design
Final note under ASD, static load test were given an FS of 2 while dynamic testing generally was about 2.5 and staic was 3