Transient surface wave was firstly used to evaluate the conditions of old highway which the layer was hard in the top while soft in the lower,the sensors was improved to adapt to the layer,the frequency spread data of base and high order modal was comprehensively used to forward and inverse the old highway surface wave velocity(SWV) along depth.

Analysis of numerical dispersion in wave-field simulation;

A numerical dispersion relationship is proposed, which is mainly influenced by both the finite difference accuracy and the grid size.

Conventional finite-difference methods for solving elastic-wave equation suffer from numerical dispersion when too few samples per wavelength are used.

This paper first introduces the modified Anas Abo Zena's method for computation of surface waves dispersion functions, which is a stable algorithm at very high frequency and can be used to compute the dispersion curves for site investigation and non-intrusive diagnosis.

Using combined mass matrix to suppress numeric dispersion;

Wave-equation finite-difference algorithm can more preciously simulate seismic wavefield for any non-uniform medium,but have the issue of numeric dispersion.

Study and implementation on discrete data triangle mesh algorithm;

Reversing surface STL format file from many blocks of 3D discrete data cloud;

An effective contour generating method for discrete data;

Arithmetic for the realization of freeform surface triangular mesh based on the scattered data;

Introduced a method of NC machining tool-path generation based on scattered data model.

Through VBA programming,the interpolating algorithm is applied to create fit curve in AutoCAD from scattered data and interpolate its value at certain point without constructing complex interpolation equation.