Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 Advancements in active surface wave methods: modeling, testing, and inversion Shibin Lin Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Civil Engineering Commons Recommended Citation Lin, Shibin, "Advancements in active surface wave methods: modeling, testing, and inversion" (2014). Graduate Theses and Dissertations. 13761. https://lib.dr.iastate.edu/etd/13761 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Advancements in active surface wave methods: modeling, testing, and inversion by Shibin Lin A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Civil Engineering (Geotechnical Engineering) Program of Study Committee: Jeramy Ashlock, Major Professor Igor Beresnev Halil Ceylan Thomas Rudolphi R. Christopher Williams Iowa State University Ames, Iowa 2014 Copyright © Shibin Lin, 2014. All rights reserved. ii DEDICATION To the memories of Qiumei Li (1915-2008) and Quanhang Huang (1935-2008). iii TABLE OF CONTENTS LIST OF TABLES ........................................................................................................... vii LIST OF FIGURES ........................................................................................................ viii ACKNOWLEDGEMENTS ........................................................................................... xvii ABSTRACT .................................................................................................................. xviii CHAPTER 1. INTRODUCTION ...................................................................................... 1 1.1 Background .................................................................................................. 1 1.2 Literature Review......................................................................................... 2 1.2.1 Rayleigh waves ........................................................................................ 2 1.2.2 Surface wave testing methods and experimental dispersion analysis ...... 3 1.2.3 Inversion ................................................................................................... 4 1.3 Objectives and Significance of the Dissertation .......................................... 7 1.4 Dissertation Organization ............................................................................ 9 CHAPTER 2. RAYLEIGH WAVE MODELING BY ANALYTICAL AND COMPUTATIONAL METHODS ................................................................................... 10 2.1. Introduction ................................................................................................ 10 2.2. Generation of Rayleigh Waves .................................................................. 10 2.3. Basic Assumptions for Analysis of Rayleigh Waves ................................ 16 2.4. Rayleigh Wave Solutions for a Homogeneous, Isotropic, Elastic Half-space .................................................................................................. 20 2.4.1. Equations of motion............................................................................ 20 2.4.2. Solution of Navier’s equations of motion for Rayleigh waves .......... 22 2.5. Computational Modeling of Rayleigh Wave Motion and Dispersion Behavior in Layered Media ....................................................................... 32 2.5.1. Transfer matrix method ...................................................................... 34 2.5.1.1. Case 1: Layered soil system with traction-free top surface overlying a half-space .................................................................... 38 2.5.1.2. Case 2: Degeneration of solution for a layered, free plate ............. 39 2.5.2. Global matrix method ......................................................................... 41 2.5.2.1. Case 1: Layered soil system with traction-free top surface overlying a half-space .................................................................... 42 2.5.2.2. Case 2: Degeneration of solution for a layered, free plate ............. 45 2.5.3. Stiffness matrix method ...................................................................... 48 2.5.3.1. Case 1: Layered soil system with traction-free top surface overlying a half-space .................................................................... 49 2.5.3.2. Case 2: Degeneration of solution for a layered, free plate ............. 57 2.6. Matrix Modeling Theoretical Dispersion Curves ...................................... 57 2.6.1. Zero determinant: bisection searching technique for real wavenumber ....................................................................................... 58 iv 2.6.2. Zero determinant: two dimensional searching technique for complex wavenumber ......................................................................... 61 2.6.3. Smallest absolute determinant technique ........................................... 62 2.6.4. Phase-velocity scanning technique ..................................................... 63 2.7. Finite Element Modeling of Surface-wave Testing on a Half-space Media ........................................................................................................ 67 2.7.1 FEM simulation of a homogeneous half-space with ALID ................... 68 2.7.2 Simulation of surface wave test on a layered soil system using FEM with ALID .............................................................................................. 73 2.8. Conclusions ................................................................................................ 74 CHAPTER 3. PHASE-VELOCITY AND INTERCEPT-TIME SCANNING (PIS) TECHNIQUE FOR IMAGING SURFACE WAVE DISPERSION CHARACTERISTICS ..................................................................................................... 76 3.1 Abstract ...................................................................................................... 76 3.2 Introduction ................................................................................................ 77 3.3 Phase-velocity and Intercept-time Scanning (PIS) Method ....................... 80 3.3.1 Synthetic data ......................................................................................... 80 3.3.2 Fourier transform to extract harmonic signals from field data............... 81 3.3.3 MASW wavefield transformation method ............................................. 84 3.3.4 Phase-velocity and intercept-time scanning (PIS) analysis.................... 90 3.3.5 Auto power spectral analysis.................................................................. 93 3.3.6 Spectral ratio .......................................................................................... 95 3.4 Case Studies ............................................................................................... 97 3.4.1 MSOR Tests at East River Valley site ................................................... 98 3.4.2 MASW tests at NGES ............................................................................ 99 3.4.3 Finite element simulation ..................................................................... 101 3.5 Conclusions .............................................................................................. 103 CHAPTER 4. SURFACE-WAVE TESTING OF SOIL SITES USING MULTICHANNEL SIMULATION WITH ONE RECEIVER ..................................... 104 4.1 Abstract .................................................................................................... 104 4.2 Introduction .............................................................................................. 104 4.3 FEM Simulations of MASW and MSOR at Soil Sites ............................ 107 4.3.1 Case 1: Site with three horizontal layers .............................................. 108 4.3.2 Case 2: Site with a vertical fault........................................................... 109 4.3.3 Case 3: Site with dipping interface ...................................................... 112 4.4 Effect of Inconsistencies in MSOR Impact Locations ............................. 114 4.4.1 Lags of stacking signals ....................................................................... 114 4.4.2 Effect of inconsistent impacts on dispersion curves ............................ 117 4.5 Field Case Studies of MSOR Testing for Soil Sites ................................ 119 4.6 Conclusions .............................................................................................. 122 CHAPTER 5. SURFACE WAVE TESTING OF PAVEMENTS................................. 123 5.1 Abstract .................................................................................................... 123 v 5.2 Introduction .............................................................................................. 123 5.3 Surface Wave Testing Systems and Experimental Issues ........................ 126 5.4 DAQ Program .......................................................................................... 130 5.5 Consistency of Impacts ...........................................................................