Structural Engineering Commons^™

Cost-Efficient Bridge Scour Health Monitoring Using Commercial Sensors, Connor Embleau, Tien Yee, Metin Oguzmert, Mahyar Amirgholy, Alan Akazemi, Dale Goff

Symposium of Student Scholars

Bridge scouring has been a major international issue regarding bridge health and the overall longevity of a bridge. A common bridge health concern such as scouring accounts for close to 60% of bridge failures in the United States and is a leading cause to a bridge being in critical condition. Traditional methods to combat this failure is to measure the scour depth to assess a bridge health. Due to safety concerns of the traditional method, this study proposes to monitor a bridge’s health using a vibration-based technique. At present, vibration-based techniques have yet to be utilized reliably in the field. …

Fast Forest Fire Smoke Detection Using Mvmnet, Yaowen Hu, Jialei Zhan, Guoxiong Zhou, Aibin Chen, Weiwei Cai, Kun Guo, Yahui Hu, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Forest fires are a huge ecological hazard, and smoke is an early characteristic of forest fires. Smoke is present only in a tiny region in images that are captured in the early stages of smoke occurrence or when the smoke is far from the camera. Furthermore, smoke dispersal is uneven, and the background environment is complicated and changing, thereby leading to inconspicuous pixel-based features that complicate smoke detection. In this paper, we propose a detection method called multioriented detection based on a value conversion-attention mechanism module and Mixed-NMS (MVMNet). First, a multioriented detection method is proposed. In contrast to traditional …

Reducing Early-Age Shrinkage Cracks Of Bridge Decks And Rails, Soumitra Das, George Morcous, Jiong Hu

UNL Student Research Days Posters, Graduate

Early-age shrinkage cracking of concrete bridge decks and rails accelerates the penetration of water and chemicals which leads to reinforcement corrosion, delamination, and eventually spalling. All this results in shorter service life, road closure, and costly repair. Development of Low-cement concrete(LCC) mix to reduce early age shrinkage crack through aggregate grading optimization was done in this research work. This approach also reduces concrete cost ($15-$20/cyd) (15–25%) and its carbon footprint (≈15%).

Evaluating The Effects Of Shored Construction On Steel Girder Composite Bridges, Parker Brooks

Doctoral Dissertations and Master's Theses

Steel composite girder bridges provide economic advantages and higher load-carrying capacity than non-composite alternatives. Over the years, a conventional sequence of un-shored construction for steel girder composite bridges has been developed. There is an alternative construction sequence, known as shored construction, that uses temporary supports (discretely or fully supported) for the superstructure during the installation of metal forms and the pouring of concrete. Shored construction also can be used in an Accelerated Bridge Construction (ABC) practice where construction occurs at a nearby site and fully-formed elements are transported to the final site using self-propelled modular transporters (SPMTs). In order to …

Euplectella Aspergillum’S Natural Lattice Structure For Structural Design & Stability Landscape Of Thin Cylindrical Shells With Dimple Imperfections, Zoe Y. Sloane

Masters Theses

The first portion of this thesis assesses the structural application of a bracing design inspired by the deep-sea sponge, Euplectella Aspergillum. Many studies have investigated the natural strength found in the unique skeletal structure of this species. The braced design inspired by the sponge features square frames with two sets of cross-braces that are offset from the corners of each frame, creating a pattern of open and closed cells. This study reports the results of multiple Finite Element Analysis (FEA) computations that compare the described bracing pattern to a more common bracing design used in structural design. The designs …

Toward Dexterous Aerial Manipulation Using Embodied Human-Intelligence For Bridge Inspection And Maintenance, Dongbin Kim

INSPIRE Archived Webinars

Current drones perform a wide variety of tasks in surveillance, photography, agriculture, package delivery, etc. However, these tasks are performed passively without the use of human interaction. Aerial manipulation shifts this paradigm and implements drones with robotic arms that allow interaction with the environment rather than simply sensing it. Many research groups have demonstrated aerial manipulation for various applications for over a decade. For example, in construction, aerial manipulation in conjunction with human interaction could allow operators to perform several tasks, such as hosing decks, drill into surfaces, and sealing cracks via a drone. This integration with drones will henceforth …

Bc-Dunet-Based Segmentation Of Fine Cracks In Bridges Under A Complex Background, Tao Liu, Liangji Zhang, Guoxiong Zhou, Weiwei Cai, Chuang Cai, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Crack is the external expression form of potential safety risks in bridge construction. Currently, automatic detection and segmentation of bridge cracks remains the top priority of civil engineers. With the development of image segmentation techniques based on convolutional neural networks, new opportunities emerge in bridge crack detection. Traditional bridge crack detection methods are vulnerable to complex background and small cracks, which is difficult to achieve effective segmentation. This study presents a bridge crack segmentation method based on a densely connected U-Net network (BC-DUnet) with a background elimination module and cross-attention mechanism. First, a dense connected feature extraction model (DCFEM) integrating …

To Critically Review The Use Of Screencasts For Teaching Land Surveying, Eugen Niculae, Alain Chenaux

Conference papers

Screencasting tools allow for a screen capture of the actions on a computer screen with accompanying audio. This research initially reviews through the literature how screencasting has been used pedagogically and, through this primary research, the application of an existing screencast called Screencast-O-Matic and feedback from students from both Construction Management and Geospatial Surveying Undergraduate Programmes of TU Dublin, where and how it could be deployed for the surveying classes and fieldwork during the pandemic situation. This research occurred when all Irish third-level institutions lectures and tutorials moved online, and access to survey equipment for fieldwork was severely reduced. The …

Influence Of Phosphorus Sources On The Compressive Strength And Microstructure Of Ferronickel Slag-Based Magnesium Phosphate Cement, Cuirong Yan, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Luxing Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Electric furnace ferronickel slag (EFS) is a typical magnesium-rich industrial by-product discharged from the manufacture of nickel and iron-nickel alloys. The approach to use it as the raw material for the preparation of magnesium phosphate cement (MPC) has potential and proves effec-tive. In this study, three different phosphorus sources (PS) including phosphoric acid (H₃PO₄, PA), sodium dihydrogen phosphate (NaH₂ PO₄, SDP) and potassium dihydrogen phosphate (KH₂ PO₄, PDP) were used to react with EFS to prepare the EFS-based MPC (EMPC), and the effects of raw material mass ratio (EFS/PA, EFS/SDP, …

Effects Of Long Duration Earthquakes On The Interaction Of Inertial And Liquefaction-Induced Kinematic Demands On Pile-Supported Wharves, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Nason Mccullough, Scott Schlechter

Civil and Environmental Engineering Faculty Publications and Presentations

Nonlinear dynamic analyses were performed to evaluate the effects of ground motion duration on the dynamic response of a pile-supported wharf subjected to liquefaction-induced lateral ground deformations. The numerical model was first calibrated using recorded data from a well-instrumented centrifuge test, after which incremental dynamic analyses were conducted using a suite of spectrally matched motions with different durations. The nonlinear dynamic analyses were performed to evaluated three loading scenarios: combined effects of inertial loads from the wharf deck and kinematic loads from ground deformations, deck inertial loads only in the absence of liquefaction (with minimal kinematic loads), and kinematic loads …

A Computational Fluid Dynamics-Based Surrogate Wind Turbine Blade Aerodynamic Model For Hybrid Simulation, Eric Lalonde

Electronic Thesis and Dissertation Repository

Hybrid simulation (HS) is a promising technique for studying wind turbines due to the presence of scaling errors in wind tunnel testing. However, HS of wind-loaded structures is limited by the current practice of using lower-accuracy, "pre-calculated" aerodynamic loads, which uncouple the aerodynamic loading from the structural response. This thesis presents six stand-alone studies that collectively build towards a novel HS framework that employs a computational fluid dynamics (CFD) based surrogate model to generate higher-accuracy aerodynamic loads within the HS loop. An experimentally-validated residential wind turbine model equipped with an external damping system was used to illustrate the proposed framework. …

Setting Times Of Early-Age Mortars Determined From Evolution Curves Of Poisson’S Ratio, Bate Bate, Xiao Chen, Chao Chen, Hongyan Ma, Jianfeng Zhu, Junnan Cao, Jiakai Chen, Kamal Khayat, Shuai Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Setting times, as the early-age properties of cement-based materials, are important properties to ensure the quality and long-term performance of engineering structures. To determine the initial and final setting times of cementitious materials, the compressive wave velocity and shear wave velocity of six early-age mortar samples were monitored. Their time evolution curves of Young's modulus, shear modulus, bulk modulus, and Poisson's ratio were then calculated and analyzed. The signature times of the derivatives of the Poisson's ratio evolution curves correlate well with the initial and final setting times, and the remarkably high coefficient of determination values relative to the data …

Blast Analysis Of Steel-Plate Composite Slabs: Sdof And Fem Analyses, Joshua R. Harmon, Amit H. Varma

Bowen Laboratory Research Reports

Steel-plate composite (SC) members have emerged as competitive construction methods for tall buildings and nuclear power plants. Detailed design guidance has been created for these functions and design of these members is now covered in AISC 341-16 and ASIC N690-18. However, SC members are emerging for use in protective structures to withstand blast and impact loads. Although experimental tests of SC members for blast resistant design have been conducted, design of SC members for blast loads has not been addressed in existing design references for blast loadings (UFC 3-340-02). This report details a general design philosophy for blast loaded SC …

Strengthening Of Long Rc Columns Using Near Surface Mounted Gfrp Bars, Ahmed Romaih

Theses and Dissertations

Many of the existing reinforced concrete (RC) columns are deficient because of numerous reasons such as increase in service loads, deterioration due to environmental attacks, errors in the design and/or construction phase or in the worst case, accidents. These elements require strengthening or repair. Different methods have been developed over the years for solving different rehabilitation problems. Recently, advanced composites used for external bonding in the form of fabrics or laminates have become an accepted method. The use of Fibre-Reinforced Polymers (FRPs) in this process is a promising technology, especially that these materials are corrosion-free. One of the new techniques …

Flexural Strengthening Of Rc Slabs Using Near Surface Mounted Gfrp Bars, Sama Taha

Theses and Dissertations

Glass Fiber reinforced polymers (GFRPs) have been recently successfully used to increase reinforced concrete elements' strength. In general, FRPs have many advantages such as resistance to corrosion, and high strength-to-weight ratio. On the other hand, debonding from concrete may constitute a limitation to using GFRP bars; hence the increase in strength of RC elements strengthened using GFRP bars may be limited by this premature debonding failure mechanism.

This study aims to investigate the strengthening effect of GFRP bars on the capacity of RC slabs when subject to flexure loading. The work studies the use of different bonding lengths, diameters and …

Steel Diaphragm Innovation Initiative, Year 5, Final Report *Addendum*, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

Preface

The Steel Diaphragm Innovation Initiative (SDII) is a multi-year industry-academic-government partnership to advance the seismic performance of steel floor and roof diaphragms utilized in steel buildings. This addendum to the final report covers work conducted on Task 5.6 which was completed during a no-cost extension conducted in 2021. Please refer to AISI RP21-04, the Steel Diaphragm Innovation Initiative, Year 5, Final Report for all other details.

Inspire Newsletter Spring 2022, Missouri University Of Science And Technology. Inspire - University Transportation Center

INSPIRE Newsletters

No abstract provided.

Stress Change Calculations In Accidentally Damaged Prestressed Bridge Girders, Habib Tabatabai, Azam Nabizadeh

Civil and Environmental Engineering Faculty Articles

Accidental damage to prestressed concrete bridge girders may occur due to impact by over-height vehicles on the bottom of the girder, or the top flange of the girder may be damaged during deck removal and replacement operations. Since stress checks at service loads are an important component of design for prestressed concrete beams, serviceability-based stress checks should be considered when assessing the structural condition of damaged girders. In this paper, step-by-step theoretical calculations are used to develop equations for estimating service load stress changes due to physical damage (partial loss of concrete section and strands) based on a differential approach. …

An Examination Of Effective Length In Moment Frames, Connor Stephen Schott

Honors Theses and Capstones

The honors thesis project I have been working on is called An Examination of Effective Length in Moment Frame. When loaded axially in compression columns experience a failure mode in compression that axially loaded members don’t experience in tension. This failure mode, elastic column buckling, doesn’t involve yielding or rupture; the column changes shape and deforms to the side. In order to come up with a solution to this failure mode, Leonhard Euler developed the critical buckling load equation. However, this equation uses an effective length of columns, which is the distance between two points of zero moment, or …

Quantitative Bridge Inspection Ratings Using Autonomous Robotic Systems, Anil K. Agrawal

Project IM-2

Impact sounding has been recognized as an effective technique to detect delamination in concrete structures, such as concrete decks. An enormous amount of sounding data can be generated/collected by the autonomous inspection systems equipped with impactors and microphones. However, the main challenge in the practical application of this technology is the development of advanced data analysis approaches for identifying defects from impact sounding data. In this study, the empirical mode decomposition (EMD) analysis and power-spectral density (PSD) analysis are combined to extract useful features of sounding data generated by the impact hammer. It has been found that the EMD method …