## Wave Equation Analysis

## Wave Equation Analysis

(OP)

Ok, I understand that the basic purpose of the Wave Equation is develop a plot of load capacity versus blow count. So does this mean if you were using wave equation analysis alone, you could specify the contractor to drive piles until you reach the blow count that corresponds to the intended capacity?

## RE: Wave Equation Analysis

## RE: Wave Equation Analysis

The wave equation will not tell you actual energy transfer.

The wave equation will not predict relaxation or set up

Monotube and taper piles require residual stress analysis.

## RE: Wave Equation Analysis

Statistically, the ratio of predicted static capacity to actual capacity (as determined by a static load test and using the Davisson offset criteria) is about the same. However, the WEAP approach has a smaller standard deviation and COV.

The FHWA modified Gates formula has statistically much better results than either WEAP or the ENR formula in terms of ratio of predicted capacity, std deviation and COV.

See NCHRP Report 507 and FHWA NHI-05-052 for more information. Discussion of dynamic methods for estimating pile capacity is in FHWA NHI-05-042/-043. The first two publications should be available for download from the internet. The last two publications are available on CD from DFI (www.dfi.org).

There are much better formulas than the ENR formula. The ENR formula should not be used. Period.

As DRC1 says, verify/calibrate with at least one actual test pile before you finalize the design if the number of piles and consequences of excessive pile movement warrant.

J