Structural Engineering Commons^™

3d Microwave Camera For Concrete Delamination And Steel Corrosion Detection, R. Zoughi

INSPIRE-UTC Annual Meetings

Corrosion of embedded steel reinforcement in concrete leads to concrete cracking and delamination, followed by increased salt and moisture permeation and further damage. Invisibility of the embedded rebar in combination with physical inaccessibility in elevated bridges presents a challenge in the assessment of RC bridge elements. Wideband (3D) microwave synthetic aperture radar (SAR) imaging techniques that can be integrated into a UAV offer a practical solution to overcome this challenge.

This project aims to develop and optimize a 3D microwave camera for bridge inspection on a UAV platform, quantify its performance for steel corrosion evaluation and concrete delamination detection in …

Autonomous Ultrasonic Thickness Measurement By A Magnet-Wheeled Robot, Yang Wang

INSPIRE-UTC Annual Meetings

A wireless sensing device recently developed by PI Wang’s group has demonstrated various structural sensing capabilities for bridge applications. In the meantime, a latest robot platform developed by Dr. La’s group at the University of Nevada, Reno (UNR) demonstrates promising performance navigating on steel bridge members. Marrying the two state-of-the-art developments, this project will produce a magnet-wheeled robot capable of autonomous nondestructive measurement on steel bridge structures. Both laboratory and field validations will be performed.

This project will integrate advanced wireless sensing technologies to the UNR robot platform. At first, the functionality of ultrasonic thickness measurement will be developed on …

2020 Technical Program, Inspire - University Transportation Center

INSPIRE-UTC Annual Meetings

INSPIRE University Transportation Center 2020 Annual Meeting
August 3-4, 2020

Investigation Of Modeling Strategies For Slender Lightly Reinforced Concrete Shear Walls, Jenna Marie Williams, Tracy Destiny Doan

Architectural Engineering: Graduate Reports

A large number of pre-1980’s non-ductile reinforced concrete (RC) structures in California utilizing RC shear walls to resist seismic lateral forces have been identified as deficient by industry practitioners. These non-ductile wall systems are typically lightly reinforced and lack adequate boundary element detailing. Analytical studies suggest these walls are susceptible to brittle, compression-controlled failure modes due to damage from concrete crushing and bar buckling. Furthermore, poor behavior of lightly reinforced concrete walls was observed in many recent earthquakes, for example in Chile (1985), New Zealand (2010/2011) and Mexico (2017). This has generated concern among engineers in high seismic regions around …

Seismic Design Coefficients For Speedcore Or Composite Plate Shear Walls - Concrete Filled (C-Psw/Cf), Shubham Agrawal, Morgan Broberg, Amit H. Varma

Bowen Laboratory Research Reports

This report summarizes the results from FEMA P695 analytical studies conducted to verify the seismic design factors for composite plate shear walls – concrete filled (C-PSW/CF), also referred to as Speedcore. ASCE 7-16 provides the seismic design factors, which include the seismic response modification factor, R, deflection amplification factor, C_d, and overstrength factor, Ω_o, for various approved seismic systems. C-PSW/CFs are assigned a response modification factor of 6.5, a deflection amplification factor of 5.5, and an overstrength factor of 2.5 for C-PSW/CFs. These seismic design factors were selected based on the seismic performance of similar structural …

Wind Uplifting Performance Of Roof-To-Wall Connections And Roof Structures With Elastomeric Adhesives In Light-Frame Wood Buildings, Bilal M. Alhawamdeh

Dissertations

Light-frame wood residential buildings are highly susceptible to damage caused by severe wind events such as hurricanes and tornados. Roof failures in residential buildings are commonly observed due to weaknesses of or missing connections. Roof-to-wall connections not only have significant influences on roof performance but also affect building resistance due to their critical role of transferring wind loads to the wall system and ultimately to the foundation. Roof fails when it has no sufficient wind uplift resistance due to improper selection or installation of construction materials (including fasteners) and strength degradation due to aging or long service. Toenailing is commonly …

Development Of Bragg Fiber Sensor For Corrosion Detection, Cai Hui Tan

Student Works (2020-2029)

Steel corrosion has posed one of the major structural defects in the civil society today. Conventional methods for corrosion monitoring involve high maintenance cost and destructive methods with low accuracy. Recently, Fiber Bragg gratings (FBG) sensor with its high sensitivity in measuring strain and temperature have been widely studied and used in structural health monitoring (SHM). A non-destructive corrosion detection approach based on FBG sensors was developed and tested to monitor corrosion in this research work. The principle of FBG sensing is based on Bragg wavelength shifts that from the corrosion process that induced strain on the FBG due to …

Improved Ballistic Limit Equations For High-Speed Non-Aluminum Projectiles Impacting Aluminum Dual-Wall Spacecraft Systems, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

One of the major design considerations of earth-orbiting spacecraft is the damage that might occur from an impact by a micrometeoroid or orbital debris particle. Ballistic limit equations (BLEs), which predict the response of spacecraft components under impact, are one of the key components of any micrometeoroid / orbital debris risk assessment calculation. However, given that a limited number of BLEs have been developed, analysts will sometimes use a BLE to assess the impact projectile made of a material that was not used in the development of that BLE. This paper presents the results of a two-part study that focused …

Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on transmission electron microscopy (TEM) grids. AgNW …

Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on transmission electron microscopy (TEM) grids. AgNW …

Examining The Effects Of Reducing The Cement Content Of Portland Cement Concrete Pavement, Bryan Casillas

Graduate Theses and Dissertations

Portland cement is a significant component in a concrete mixture. For concrete used in portland cement concrete pavement (PCCP), the Arkansas Department of Transportation (ARDOT) specifies a minimum cementitious material content of 564 lb/yd3 and a maximum water-cementitious material ratio of 0.45. Prior research conducted at the University of Arkansas, TRC 0603, indicated concrete mixtures used in five bridge decks throughout Arkansas achieved the required 28-day strength at seven days, and the measured compressive strength at 28 days was 30% greater than required. The use of high strength concrete in pavements throughout the state can increase cracking and consequently reduce …

Verifying The Calcium Oxychloride Threshold In Cementitious Pastes, Fatoumata Traore

Graduate Theses and Dissertations

Calcium oxychloride (CAOXY) formation is a serious deterioration mechanism known to cause joint damage in concrete pavements. CAOXY is the product of a chemical reaction between calcium chloride (CaCl2) or magnesium chloride (MgCl) deicing salts and calcium hydroxide in the cementitious matrix. Currently, the accepted CAOXY threshold at which deterioration is mitigated in cementitious paste is 15 g/100 g paste (15 oz/100 oz paste); however, this limit was developed using flexural strength testing. For this investigation, the current threshold was evaluated using compressive strength and mass change over time in paste specimens exposed to CaCl2. Fly ash is used to …

Commodity-Based Freight Activity On Inland Waterways Through The Fusion Of Public Datasets For Multimodal Transportation Planning, Magdalena I. Asborno

Graduate Theses and Dissertations

Within the U.S., the 18.6 billion tons of goods currently moved along the multimodal transportation system are expected to grow 51% by 2045. Most of those goods are transported by roadways. However, several benefits can be realized by shippers and consumers by shifting freight to more efficient modes, such as inland waterways, or adopting a multimodal scheme. To support such freight growth sustainably and efficiently, federal legislation calls for the development of plans, methods, and tools to identify and prioritize future multimodal transportation infrastructure needs. However, given the historical mode-specific approach to freight data collection, analysis, and modeling, challenges remain …

The Use And Explanation Of The Phase Angle In Forced Vibration Testing, Nicholas R. Slavin, Ryan D. Thornton

Architectural Engineering

Forced vibration testing is a tool used to characterize a structure’s dynamic properties. When subjecting a structure to a forced harmonic load, the results help define the structure’s fundamental frequencies and dominant mode shapes. However, when conducting testing, it is difficult to determine the contributions of each mode to the response at a given location in the structure. The recorded response from a forced vibration test is a combination of unknown modal constituents. Excitation may not result in the pure, single mode response that the experimenter desires, but may instead result in a combination of modal responses that obscure the …

Multimode-Interference Based Optical Fiber Sensor For Civil Structures Monitoring, Sue Ping Chew

Student Works (2020-2029)

The thesis describes the experimental investigations on the multimode interferencebased fiber sensors using single mode multimode single mode (SMS) and multimode single mode multimode (MSM) structures as a sensing device for structural health monitoring (SHM) applications. Both sensor structures were fabricated, characterized and tested for detecting strain and vibration in civil infrastructures. The proposed SMS structure comprises of a short segment of multimode fiber (MMF), which were fusionspliced by two single mode fibers (SMFs) at both terminals. On the other hand, MSM was fabricated by splicing SMF with MMF at both ends. A new packaging technique for the SMS structure …

Performance Of A New Passive Damper For Seismic Protection Of Structures, Ghaedi Khaled

Student Works (2020-2029)

Passive energy dissipation devices have been successfully implemented in buildings around the world to reduce structural responses primarily to earthquakes, wind and other dynamic loads. Unlike active and semi-active control systems, passive systems make use of control devices that serve secondary functions. They are connected to structural members to increase structural damping without the use of external forces. The aim of this research is to introduce and investigate the performance of a new passive damper device called bar damper (BD), which is made of a number of solid bars sandwiched between two plates. The concept, placement and material properties of …

Engineering Properties And Microstructural Characteristics Of Cement And Geopolymer Based Mortars Using Nontraditional Supplementary Cementitious Materials, Mathialagan Sumesh

Student Works (2020-2029)

The concrete repair and rehabilitation industry grows rapidly due to deterioration, damage and defects in concrete structures. For various reasons, the concrete construction industry is not sustainable; because it consumes huge quantities of virgin materials, the usage of Portland cement as prime binder. The production of cement is a major contributor to greenhouse gas emissions. In addition, the high cost of commercial repair material. Therefore, it is necessary to develop cost-effective alternative repair materials for concrete repairs. There have been many standard repair materials available in the market, which are costly and not affordable to common people. However, research works …

Stability Of Fiber-Reinforced Bridge Bearings Under Compression And Shear Loads, Andrea Calabrese, Simone Galano, Tran Nghiem

Mineta Transportation Institute

Fiber-Reinforced Bearings (FRBs) have proven to be a valuable rubber-based base isolation technology in which flexible fiber reinforcements are used to replace the steel layers commonly adopted for the manufacturing of Laminated Rubber Bearings (LRBs). Thanks to the low weight and cost of FRBs, these devices could prove to be instrumental for the promotion of base isolation applications to houses and residential buildings of developing countries in seismic regions. This report presents the results of a large set of Finite Element Analyses (FEAs) aimed at assessing the performance of FRBs under combined axial and shear loads. The effects of different …

Final Report - Bridge Resilience Assessment With Inspire Data, Iris Tien, Yijian Zhang

Project RR-1

This project proposed a methodology to assess the impact of corrosion on the performance of bridges. The combined analytical and numerical modeling of shear-critical and lap-spliced columns is detailed, and outcomes are verified with previous experimental test data. The impact of corrosion on risk is assessed through conducting fragility analyses. Results quantify the increase in failure probabilities of these structures, measured by increasing probabilities of exceeding defined damage states, with increasing levels of corrosion. Corrosion is found to have a larger impact on increasing probabilities of exceeding more severe damage states. Twenty percent mass loss of reinforcement increases the probability …

Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Concrete deck delamination often demonstrates strong variations in size, shape, and temperature distribution under the influences of outdoor weather conditions. The strong variations create challenges for pure analytical solutions in infrared image segmentation of delaminated areas. The recently developed supervised deep learning approach demonstrated the potentials in achieving automatic segmentation of RGB images. However, its effectiveness in segmenting thermal images remains under-explored. The main challenge lies in the development of specific models and the generation of a large range of labeled infrared images for training. To address this challenge, a customized deep learning model based on encoder-decoder architecture is proposed …

Mobile Manipulating Drones, Paul Oh

INSPIRE Archived Webinars

In the past few years, robotic limbs have been attached to rotorcraft drones to perform aerial manipulation. Unlike simple object pick-and-place, such mobile-manipulating drones are dexterous to perform tasks like valve-turning, hatch-opening, and tool-handling. This is a paradigm shift where such drones actively interact with their environment rather than just passively surveil. Aerial manipulation is challenging because such interaction yields reaction forces and torques that destabilize the drone. This talk will provide an overview of aerial manipulation and showcase examples that could serve in infrastructure inspection, maintenance, and repair.

Constraint-Type Fictitious Time Integration Method For Solving Non-Linear Multi-Dimensional Elliptic Partial Differential Equations, Yung-Wei Chen, Chein-Shan Liu, Yen-Shen Chang, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

In this paper, we propose a constraint-type fictitious time integration method (FTIM) for solving multi-dimensional non-linear elliptic-type partial differential equations. Based on the variable transformation of FTIM, the original governing equation is transformed into a new parabolic equation of an evolution type by introducing a space-time variable, and a new time integration direction is obtained. However, the space-time variable depends on the governing equation, boundary condition and fictitious time variable, especially due to the nonlinear effect. Previous studies have not discussed the definition of these nonlinear parameter problems, which may result in severe numerical instability and inaccuracy. To completely overcome …

A Comparative Study On Seismic Analysis Methods And The Response Of Systems With Classical And Nonclassical Damping, Noah G. Bleichner

Master's Theses

This thesis investigated the application of seismic analysis methods and the response of idealized shear frames subjected to seismic loading. To complete this research, a Design Basis Earthquake (DBE) for a project site in San Luis Obispo, CA, and five past earthquake records were considered. The DBE was produced per the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures (ASCE 7-10) and used for application of the Equivalent Lateral Force Procedure (ELFP) and Response Spectrum Analysis (RSA). When applying RSA, the modal peak responses were combined using the Absolute Sum (ABS), Square-Root-of-the-Sum-of-Squares (SRSS), and Complete …

Design Of Structural Stand For High-Precision Optics Microscopy, Sara T. Novell

Master's Theses

Lawrence Livermore National Lab (LLNL) is home to the National Ignition Facility (NIF), the world’s largest and most energetic laser. Each of the 192 beamlines contains dozens of large optics, which require offline damage inspection using large, raster-scanning microscopes. The primary microscope used to measure and characterize the optical damage sites has a precision level of 1 µm. Mounted in a class 100 clean room with a raised tile floor, the microscope is supported by a steel stand that structurally connects the microscope to the concrete ground. Due to ambient vibrations experienced in the system, the microscope is only able …

Folded! High-Rise, Alejandra Bravo, Riley Joseph Denis

Architectural Engineering

The authors of this report are undergraduate Architectural Engineering students at California Polytechnic State University in San Luis Obispo. This report documents their experience in an interdisciplinary studio of high‐rise building design and the process by which they produced a schematic design of a high‐rise residential building in San Francisco. It will address the organization of the studio, the development of concept as well as form and structure, the studies and structural analyses, as well as the review process and the competitions the final proposals were entered in, and include some final takeaways from each Architectural Engineering group member.

Numerical Performance Evaluation Of The Wooden Frame Structures With Adhesive Applied Connection Under Wind And Seismic Loading, Sharthak Bhandary

Masters Theses

The objective of the research is divided into two folds. The first objective is to study the state-of-the-art modeling method for the wooden frame construction, while the second objective is to evaluate the performance of a wooden frame structure with construction adhesives under hazardous loading conditions using the selected numerical modeling method. The numerical modeling tools were classified under academic and commercial categories based on the purpose of their development. Both academic and commercial tools were further classified based on model types of the structural systems (i.e., shear walls and three-dimensional (3D) buildings) and the applied loads (i.e., wind loading …

Experimental Investigation For Moment Redistribution In Continuous Rc Beams Top Strengthened With Cfrp And Steel Plates, Amr Ibrahim, Shady Salem, Ayman Khalil, Mahmoud El-Kateb

Civil Engineering

An experimental study was conducted on eight T-section continuous reinforced concrete beams top strengthened with CFRP and steel plates. The beams had a constant cross section and flexural steel reinforcement which was designed to prevent brittle failure due to crushing of concrete before steel yielding. The plates were installed on both sides of the slab above the beam web as near surface mounted or externally bonded to investigate the effect of different plating techniques on the moment redistribution in reinforced concrete beams. The number of plates in each specimen was changed. Steel stirrups were used and designed so that no …

Analysis Of Burning Wood In The Transient State And The Application To Structural Design, Roberta Veliz, Kimberly Guzman

Architectural Engineering

Determining the extent of the contribution of exposed timber on compartment fire dynamics in open floor plans is a complex process. Designers traditionally used compartmentalization design methods which create spaces where flashover is likely, given the fuel load and ventilation conditions. However, due to the large geometric dimensions and spread of fuel, fires in open floor plans are more likely to remain as localized or traveling fires. As such, an understanding of not only ignition potential but also flame spread is critical to characterizing the contribution of exposed timber. An integral step in characterizing the potential contribution is through an …

Wine History Project Pavilion, Douglas Mcarthur

Architectural Engineering

The Wine History Pavilion Project is a continuing endeavor of Cal Poly students working on an exhibitive, traveling structure for the San Luis Obispo community. The project started during the 2019 Fall Quarter in the interdisciplinary Integrated Project Delivery (IPD) Studio and has progressed to the detailed design stage for its eventual fabrication and installation. This report discusses the detailed design stage that 4th year Architectural Engineering student, Douglas McArthur, worked on.

The Aloe: High Rise Schematic Design And Analysis, Tony Duc Nguyen, Lilliann Lan Lai

Architectural Engineering

The authors of this document are architectural engineering (ARCE) undergraduate students from California Polytechnic State University, San Luis Obispo (Cal Poly). They joined the 2020 Skyscraper Collaboratory as part of the ARCE course 415: Interdisciplinary Capstone Project. This course emphasizes the analysis and evaluation of interdisciplinary challenges associated with integrating the design and construction processes to deliver a project with respect to the design, quality, and performance expectations for a client or presented criteria. The course was taught in collaboration with industry partners and associates from the global architectural, urban planning, and engineering firm Skidmore, Owings & Merrill (SOM). Instruction …