WEAP87

WEAP (Wave Equation Analysis of Pile Driving) is the program first developed in the 1970's by Goble & Associates. It and its successors have since become the most commonly used wave equation program for the analysis of driven piles during driving. We present here WEAP87, the last freely released version of the program. Complete documentation for WEAP86 (which is similar to WEAP87) is here.

SPILE

A program for estimating the vertical load capacity of driven piles for both cohesionless (using Nordlund's method) and cohesive ones (using Tomlinson's Method.) The program is interactive and designed to analyse multilayered soils. It is primarily intended for small (less than 36") piles, such as H-beams, concrete and pipe piles. Originally developed by the FHWA. Documentation is not included but possible to obtain from McTrans.

Downloads

• The WEAP87/SPILE Program Bundle
• Documentation for WEAP86 (WEAP87 similar)

WEAP87 and SPILE are DOS programs; you will need to run it as a DOS program under the operating system you have. (Click here for information about running both of these programs under Windows XP and Vista.) Except for the output graphic most of the output of WEAP87 is either text on the screen or text files. All of SPILE's output is text.

To load and start the programs do the following:

1. Create a directory for WEAP87 and SPILE.
2. Download the ZIP file into the directory you have created.
3. Using an appropriate program (such as 7-Zip,) extract the files into the same directory. Each program is in a different directory in the compressed file, to make it easy to keep them separate.

Keep in mind that WEAP87 and SPILE are separate programs; you can use one or both of them as you need to. When applying ultimate capacities computed by SPILE to WEAP87, keep in mind that ultimate capacity and driving resistance are not the same; visit the Books on Driven Piles page at vulcanhammer.net for more information on this and other topics related to the wave equation and pile capacity.

Other Information

WEAP's current, commercial version is GRLWEAP, available from GRL. Other information of interest on WEAP is given below.

A Brief History of the Application of Stress-Wave Theory to Piles

Mohamad Hussein and George Goble

A summary of the early scientific research that forms the basis of the development of one-dimensional wave mechanics is first summarized. Beginning with the work of Donnell in the early 20th Century the subsequent analytical and computational research is reviewed in some detail. The early “wave equation” computer programs beginning in the 1940’s are described and discussed including the applications that motivated the entire development up to the present. Early measurement techniques are reviewed briefly up to the development of the resistance strain gage. This device made possible routine measurements of the force wave in the pile. The development of an accurate and reliable accelerometer was somewhat slower than the force measurement capability but usable devices were available by the time of the Michigan pile tests of 1960. The modern era of pile measurements and analysis began in earnest with the research at Case Western Reserve University. The methods for dynamic pile capacity predictions are summarized up to the present. It is estimated that today over 5000 job sites are tested and analyzed annually. The history of low strain integrity testing is presented briefly and the history of the International Stress Wave Conferences is summarized. Finally a list of American codes and standards relating to this topic is included.

Wave Equation Analysis of Pile Driving (WEAP Program)

FHWA-IP-76-14
(Also WESWEAP, Program 741-F3-R0010)
July 1976

The motivation for the preparation of the WEAP program came from problems which were experienced by the New York Departrment of Transportation when they attempted to implement routine wave equation analyses into their pile driving practice. They used a program prepared by the Texas Transportation Institute . In spite of the fact that this program was probably the most widely used wave equation program in the United States, serious difficulties were encountered in that unrealistic stresses were sometimes obtained for piles driven by diesel hammers.

The authors of this report have performed extensive research studies on pile driving emphasizing the measurement of force and acceleration during driving. These measurements involving piles driven by all types of hammers have been made for several states including New York. In order to take advantage of these measurements, the Federal Highway Administration contracted with the authors t o prepare a wave equation program which would accurately model the diesel hammer. Several years had passed since the TTI Program was developed, so it could be expected that other general improvements could be introduced into the program for all types of harmers. Finally the large volume pf available measurements of force and acceleration at the pile top were used to test the program performance.

This report is divided into four volumes:

1. The first presents a general discussion of tine use of the wave equation and how this particular program models the hammer-pile-soil system. Emhasis is placed on a discussion of the operation of diesel hamers and how that operation is modeled by WEAP.
2. The second volume provides a description of program input and output and can serve as a user's manual for the program. It is strongly recommended that all users read Volume I prior to the User's Manual so that they will understand the assumptions contained in the program and how it is intended that it be used.
3. The third volume was prepared to aid the computer operator during the initial stages of program and data file loading. It also contains a flow chart which may be of interest to those users who want to study the program in greater detail.
4. The fourth volume contains the three parts of a lecture which is also available in the form of a tape/slide show. The contents of this narrative report deal with background, models and applications of the Wave Equation.