Pile Dynamics: Field Measurement and Verification of Pile Drivability and Capacity

During the early years of stress-wave theory applied to driven piles, the only way it was done was through the wave equation program. One ran the wave equation, then checked it against field performance. However, a simple blow count check wasn't enough. Were the driving stresses predicted properly? How did the performance of the various … Continue reading Pile Dynamics: Field Measurement and Verification of Pile Drivability and Capacity

Wave Equation Analysis

By the 1920's dynamic formulae were well established in the driven pile industry. Without really consistent methods of static capacity estimation, and given the conservative nature of most foundation design, their weaknesses were not fully appreciated. The event that brought their weakness to the forefront was the development of precast concrete piles. Dynamic formulae assume … Continue reading Wave Equation Analysis

Other Monographs on the Wave Equation

Analytical Interpretation of Pile Installation and Axial Performance Hudson Matlock, Ignatius Lam and Lino Cheang A program of combined experiment and analytical studies is presently underway with the purpose of extending present understanding of the axial behaviour of pile foundations. The analytical developments are designed for back fitting and correlating the experimental results and for … Continue reading Other Monographs on the Wave Equation

Differential Equations and Laplace Transforms in Soil Dynamics

For geotechnical practicioners, the wave equation is a phenomenon which is generally dealt with using a finite element or difference computer program. For mathematicians, it is a second order, hyperbolic partial differential equation. Although the computer programs are certainly a solution to these problems (and in the case of the nonlinear phenomena just about the … Continue reading Differential Equations and Laplace Transforms in Soil Dynamics

ZWAVE

ZWAVE was Vulcan's foray into the wave equation program field. It was an outgrowth of research that dated back to the late 1970's on the magnitude of impact forces of its hammers on pile tops, so as to estimate both the loads on the equipment and the stresses on the piles. The first tangible result … Continue reading ZWAVE

TNOWAVE, IHCWAVE, APEWAVE and the Method of Characteristics

TNOWAVE was developed by TNO, the Dutch research organisation. It is different from the Smith/TTI/WEAP wave equation programs in that it uses the method of characteristics to analyse wave propagation in piles. Although there are no "public domain" versions of TNOWAVE, there are versions of TNOWAVE which have commissioned by pile driving manufacturers. We present … Continue reading TNOWAVE, IHCWAVE, APEWAVE and the Method of Characteristics

WEAP: Wave Equation Analysis of Pile Driving, with SPILE, Estimation of Pile Ultimate Capacity

The wave equation has become the standard method for predicting the drivability of piles, along with estimating stresses during driving. However, it's necessary to have some idea of the pile's ultimate capacity and driving resistance, so we are bundling the download of WEAP87 with SPILE, the FHWA program for estimating pile ultimate resistance. WEAP87 WEAP … Continue reading WEAP: Wave Equation Analysis of Pile Driving, with SPILE, Estimation of Pile Ultimate Capacity

TTI Wave Equation Program, with MICROWAVE Program

With the publication of Smith's seminal work on the wave equation for piles, the concept had found a realistic implementation--in theory at least. But then a problem arose that, although routine today, was something of a novelty at the time.Disseminating the dynamic formulae, like many other scientific and technical techniques, was fairly simple: the formula … Continue reading TTI Wave Equation Program, with MICROWAVE Program

Smith’s Wave Equation Program–the first numerical method

The work of both Isaacs and Glanville et.al. demonstrated two things: Wave propagation in piling was a real phenomenon; predicting it opened up the possibility of accurate prediction of pile stresses and resistance. The mathematical complexity of the problem--related to the complexity of the hammer-cushion-pile system, the existence of shaft friction (which, in theory, forced … Continue reading Smith’s Wave Equation Program–the first numerical method

Isaacs and Glanville: The Beginnings of the Wave Equation for Piles

The years after Wellington set forth the Engineering News Formula saw the general acceptance of dynamic formulae as a method of relating the performance of an impact hammer (drop or steam) with the bearing capacity of the pile. The technology of driven piles, however, was not standing still, and two factors in particular began to undermine … Continue reading Isaacs and Glanville: The Beginnings of the Wave Equation for Piles