Numerical Assessment of Factors Affecting Waveform Based on Low Strain Testing of Piles
In this paper dynamic testing of piles using the low strain method is performed by means of numerical analyses based on solid finite element model. To this end, velocity-time curves are presented investigating the influence of various parameters such as mesh density, impulse width, receiving point, and soil modulus on the waveform characteristics. Then, find regularity of waveform affected by different parameters to provide reference of the real project detection.
Analysis of factors to affect the hitting effect in piles' dynamic test
Local oscillator is an important aspect of the piles' dynamic test.The width of different local oscillator signals will lead to the difference of resolution of the measurement.This paper studies the simulation of the hammering effects on piles' dynamic test based on different parameters of the hammer,then discusses the variety of specific factors which leads the input pulse in time domain and frequency domain changes,summarizes the relevant rule based on the analytical data of hammer pulse and the experimental data.Furthermore,puts forward the corresponding hammer processing,gives some suggestions in application,and presents the hammer input pulse fitting form.The analysis has a more significance of academic research and application in engineering practice.
Ground Fault Protection for Electric Utility Generating Station Medium Voltage Auxiliary Power Systems
Most generating station designs have medium voltage auxiliary power systems with low resistance grounded neutrals.1 In order to provide even higher reliability, the auxiliary power distribution system configurations supply increasingly redundant process equipment.