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Civil and Environmental Engineering Commons

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Articles 1 - 6 of 6

Full-Text Articles in Civil and Environmental Engineering

Forward Time Domain Ground Penentrating Radar Modeling Of Bridge Decks For Detecting Deterioration, Kimberly Belli, Sara J. Wadia-Fascetti, Carey Rappaport Apr 2012

Forward Time Domain Ground Penentrating Radar Modeling Of Bridge Decks For Detecting Deterioration, Kimberly Belli, Sara J. Wadia-Fascetti, Carey Rappaport

Carey Rappaport

Ground penetrating radar (GPR) for nondestructive testing is a relatively young technology, especially with application to civil infrastructure such as bridges and roadways. Conventional methods of processing and analyzing GPR data for civil infrastructure are often qualitative, using relative reflection amplitude from subsurface boundaries or reinforcing steel (rebars) as an indicator of health. This poster brings well understood electrical engineering analysis tools to the application of nondestructive testing of bridges using GPR. Using iterative forward modeling to improve upon conventional permittivity and depth calculations, a computational model geometry is computed for the assumed bridge deck with no anomalies present. A …


Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram Alshawabkeh, Carey Rappaport Apr 2012

Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram Alshawabkeh, Carey Rappaport

Carey Rappaport

Soil is a complex, potentially heterogeneous, lossy, and dispersive medium. Modeling the propagation and scattering of electromagnetic (EM) waves in soil is, hence, more challenging than in air or in other less complex media. This chapter will explain fundamentals of the numerical modeling of EM wave propagation and scattering in soil through solving Maxwell’s equations using a finite difference time domain (FDTD) method. The chapter will explain how: (i) the lossy and dispersive soil medium (in both dry and fully water-saturated conditions), (ii) a fourth phase (anomaly), (iii) two different types of transmitting antennae (a monopole and a dipole), and …


Cross-Well Radar I: Experimental Simulation Of Cross-Well Tomography And Validation, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport Apr 2012

Cross-Well Radar I: Experimental Simulation Of Cross-Well Tomography And Validation, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport

Carey Rappaport

This paper explains and evaluates the potential and limitations of conducting Cross-Well Radar (CWR) in sandy soils. Implementing the experiment and data collection in the absence of any scattering object, and in the presence of an acrylic plate (a representative of dielectric objects, such as DNAPL (dense non-aqueous phase liquid) pools, etc.), as a contrasting object in a water-saturated soil is also studied. To be able to image the signature of any object, more than one pair of receiving and transmitting antennas are required. The paper describes a method to achieve repeatable, reliable, and reproducible laboratory results for different transmitter-receiver …


Experimental Validation Of A Numerical Forward Model For Tunnel Detection Using Cross-Borehole Radar, Arvin Farid, Jose A. Martinez-Lorenzo, Akram N. Alshawabkeh, Carey M. Rappaport Apr 2012

Experimental Validation Of A Numerical Forward Model For Tunnel Detection Using Cross-Borehole Radar, Arvin Farid, Jose A. Martinez-Lorenzo, Akram N. Alshawabkeh, Carey M. Rappaport

Carey Rappaport

The goal of this research is to develop an experimentally validated twodimensional (2D) finite difference frequency domain (FDFD) numerical forward model to study the potential of radar-based tunnel detection. Tunnel detection has become a subject of interest to the nation due to the use of tunnels by illegal immigrants, smugglers, prisoners, assailants, and terrorists. These concerns call for research to nondestructively detect, localize, and monitor tunnels. Nondestructive detection requires robust image reconstruction and inverse models, which in turn need robust forward models. Cross-Well Radar (CWR) modality is used for experimentation to avoid soil-air interface roughness. CWR is not a versatile …


Simulating Gpr For Diagnosis Of Civil Infrastructure, Laura Carey, Kimberly Belli, Carey M. Rappaport, Sara J. Wadia-Fascetti Apr 2012

Simulating Gpr For Diagnosis Of Civil Infrastructure, Laura Carey, Kimberly Belli, Carey M. Rappaport, Sara J. Wadia-Fascetti

Carey Rappaport

At the present, a large proportion of our nation's bridges and roadways are falling into disrepair. About 27.5% of U.S. bridges are structurally deficient or functionally obsolete (ASCE, 2001, 2003). Nondestructive testing methods, such as GPR, are becoming more and more important in diagnosing the condition of such concrete structures. GPR is a high-resolution electromagnetic technique used to investigate the immediate subsurface of the earth, building materials, roads, and bridges. This poster shows my work in GPR modeling during a summer undergraduate experience through CenSSIS. A specialized MATLAB toolbox designed by Kim Belli created all data presented here. The use …


Tunnel Detection Using Cross Borehole Radar, Clay Kurison, Arvin M. Farid, Akram N. Alshawabkeh, Carey M. Rappaport Apr 2012

Tunnel Detection Using Cross Borehole Radar, Clay Kurison, Arvin M. Farid, Akram N. Alshawabkeh, Carey M. Rappaport

Carey Rappaport

Shallow tunnels present both military and homeland security threats. Smugglers with intentions of avoiding border security have turned tunnels into transit routes for trafficking weapons, people, drugs and other illegal materials. Shallow tunnels are also used by prisoners to escape prisons. While drug and human trafficking have long been border concerns, the threat of international terrorism has transformed the effort to detect tunnels into a national security priority. Imminent threats include assailants entering military fortifications by burrowing under buildings, detonation of high grade explosives from foundations of high security facilities, and high level prisoners escaping detention centers through tunnels. Real-time …