bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Speed-Related Ride Quality Thresholds Using International Roughness Index
Authors: Yu Jianxiong , Chou Eddie Y. J. , Yau Jyh-Tyng
Published: May 2018

The International Roughness Index (IRI) has been used as a road roughness index on highways for nearly two decades. Research shows that subjective ratings such as present serviceability rating or mean panel rating could be reasonably predicted from IRI. Acceptable IRI values for highways have been developed and published by FHWA. Such IRI standards, however, are not applicable to local streets. Because vehicle speeds are lower on local streets, a comfortable ride can still be achieved at higher IRI values. There is a need to determine the acceptable IRI threshold values for local streets with various speed limits. Such IRI threshold values allow local pavement management officials to compare objectively the ride quality of streets with different speed limits. It was found that human ratings depend linearly on the logarithm of the rate of change of the vertical acceleration, namely, the jolt or jerk experienced by the raters. By analyzing the IRI records in the Long-Term Pavement Performance database and the corresponding calculated jolts, the authors found that jolt is linearly proportional to IRI at a given speed and approximately linearly proportional to the travel speed for a given IRI. By assuming further that the same jolt will lead to the same ride quality and that Interstate highways are operated at 120 km/h (75 mph), the authors use the jolt corresponding to the IRI thresholds set by FHWA for highways to develop speed-related ride quality thresholds at different travel speeds. The variation of jolt for roads with the same IRI value is also discussed.
Cash Flow Control of New Jersey Interstate Needs
Authors: Zaghloul Sameh , Helali Khaled , Ahmed Zubair , Sauber Robert , Jumikis Andris A.
Published: May 2018

In 2002, a study assessed the structural condition of New Jersey's Interstate network and determined its rehabilitation needs for the next 30 years. Deflection testing was performed on approximately 750 testing miles, and cores and bores were also taken. In addition, a ground penetration radar survey and a limited visual inspection were carried out on the entire length of the Interstate network, including the associated ramps. The data were collected to complement the data available in the Capital Program Management State Pavement Management System, such as the International Roughness Index data, which the state collects every 2 years. In addition to field testing, traffic and cost data were gathered from existing sources within the New Jersey Department of Transportation (NJDOT) and used in the rehabilitation analysis. Furthermore, by NJDOT's request, the cost of reconstructing all inside and outside shoulders to the same structural capacity as the traffic lanes was estimated. The results of the study indicated that major spending would be required in the first few years of the analysis period, followed by less spending in subsequent years. However, NJDOT's desired cash flow pattern involved beginning with lower levels of funding and then increasing spending in latter years. As a consequence, additional analyses were run to consider whether intermediate treatments could be performed in order to meet this desired cash flow. This paper presents an overview of the Interstate Rehabilitation Needs Study along with a discussion about how the desired cash flow was achieved.
Pavement Condition Prediction Using Clusterwise Regression
Authors: Luo Zairen , Chou Eddie Y. J.
Published: May 2018

In this paper, the clusterwise regression model, which fits data to more than one curve, was introduced to model the deterioration of pavement condition. To make the model solvable in practice, a modification was made to the model by the membership of a pavement to each cluster being estimated with the fuzzy sets concept with the corresponding errors. The number of unknowns in the modified model is reduced significantly. The model was then extended to be applicable to cases in which more than two clusters or nonlinear equations were used. Based on the result of the modified clusterwise regression model, a procedure was proposed to predict the pavement condition rating (PCR) for any individual pavement, given that the pavement condition rating at the present age was known. In the example, the ordinary least squares regression method was first employed to determine the PCR prediction curve for a pavement group. The PCRs of the individual pavements were predicted by an adjusted prediction curve based on the prediction curve of the group. The proposed prediction procedure was then applied to the same data set to make the predictions. The results showed that the proposed procedures using the modified clusterwise regression method could result in a smaller prediction error and thus produce a more accurate prediction than one produced with the adjusted curve. Therefore, to improve the accuracy of the pavement condition predictions, the modified clusterwise regression model is recommended in cases in which the pavement families are not well defined.
Nondestructive Testing for Crack Width and Variability on Continuously Reinforced Concrete Pavements
Authors: Kohler Erwin , Roesler Jeffery
Published: May 2018

Previous research has shown that the main failure mode in continuously reinforced concrete pavements (CRCP) is the punchout, a distress associated with the loss of load transfer capacity across transverse cracks. Despite the fact that crack width is widely recognized as one of the most important factors in CRCP punchout development, little research has been focused on effectively quantifying this variable. This paper presents results of crack width determined by measuring the crack closing movement under the action of vertical loads. The CRCP crack width data were acquired by using a rolling wheel load and a falling weight deflectometer (FWD) measuring technique. Crack width was successfully determined with an FWD, which enables future use of this device and technique to determine field CRCP crack widths. Crack width distribution is difficult to assess initially on CRCP test sections because the zero-crack width temperature needs to be known and the average pavement temperature must be less than this value during the testing. The data gathered from this study consisted of crack width from 31 transverse cracks on a uniform section, measured at the surface, when the pavement temperature was 9.5°C (average top and bottom) and the temperature differential was 0.5°C. In this case, the average width was 59 microns, and the standard deviation was 11.6 microns. On the basis of the measured crack width data, a Weibull distribution of the crack width was proposed with shape parameters related to the minimum, maximum, mean, and standard deviation of the crack width data.
Evaluation of Dowel Bar Retrofit Alternatives Using Accelerated Pavement Testing
Authors: Bian Yi , Harvey John T.
Published: May 2018

This paper presents the results of accelerated pavement testing using the heavy vehicle simulator (HVS) to evaluate the performance of dowel bar retrofit (DBR) joints and cracks as measured by deflections and load transfer efficiency (LTE). Four HVS sections were constructed and tested: one with four epoxy-coated steel dowels per wheelpath, one with three epoxy-coated steel dowels per wheelpath, one with four fiber-reinforced polymer (FRP) dowels per wheelpath, and one with one joint with four epoxy-coated steel dowels per wheelpath and the other with four hollow stainless steel dowels per wheelpath. HVS and falling weight deflectometer (FWD) testing indicated that DBR significantly improved the LTE and reduced deflections compared with the undoweled pavement. Previous HVS trafficking damaged LTE on undoweled joints, but no significant loss of LTE was found after heavy HVS trafficking on DBR joints or originally doweled joints. Under FWD testing, the LTE from DBR joints (four steel dowels per wheelpath) was typically between 85 to 90% at lower temperatures before trafficking and greater than 95% for joints with originally installed dowels. The configuration using three dowels per wheelpath was found to have significantly lower LTE than that using four dowels per wheelpath. FRP and grout-filled hollow stainless steel dowels had similar performance to epoxy-coated steel dowels. The equivalent built-in temperature difference values of after-DBR sections are lower than those of before-DBR sections, likely as a result of the time of construction when the slabs were expected to be flattest. This finding indicates that tensile stresses in the concrete slabs could also be decreased by DBR.
Accelerated Pavement Testing to Compare Efficiency of Overlay Materials Used in Brazil
Authors: Núñez Washington Peres , Ceratti Jorge Augusto Pereira , Theisen Klaus Machado , Morilha Armando
Published: May 2018

In Brazil, asphalt rubber (AR) has been used to delay reflection cracking in overlays since the 1990s. To quantify reflection cracking evolution in AR and asphalt concrete (AC) overlays, an accelerated pavement testing (APT) study was carried out by the Federal University of Rio Grande do Sul and the State Roads Department. Overlays 5.0-cm thick were set on sections with identical structures (severely cracked AC wearing course and granular base), and from March 2003 to February 2005 a traffic simulator applied 100-kN axle loads on the two full-scale pavements. During the tests, cracks were recorded, and deflections and strains were measured. APT raw data suggested that the efficiency of the AR overlay in delaying reflection cracking was 5.55 times greater than that of the AC overlay. Because the overlays were tested in different seasons, a supplementary laboratory study was carried out to quantify temperature effect on AC and AR resilient modulus, later used in a fatigue analysis. With APT and fatigue analysis data combined, it was possible to ascertain that if both overlays were tested at identical pavement temperatures, the efficiency of the AR overlay delaying reflection cracking would be 4.84 times greater than that of the AC overlay.
Evaluation of Full-Sized Cast-in-Place Pile Capacity with Artificial Defects
Authors: Jung Gyungja , Kwon Oh Sung , Jung Sung Jun , Kim Myoung Mo
Published: May 2018

Cast-in-place piles in the field are likely to have unintended defects during construction, such as soft bottom, segregation of concrete, and contraction or enlargement of the cross section. The effect of defects in cast-in-place piles on the pile's resistant behavior was evaluated. Four piles with artificial defects of soft bottom, concrete segregation, and contractions of the cross section by 10% and 20%, respectively, as well as one sound pile, were constructed simultaneously. Static load tests, load transfer measurements, and integrity tests were performed for the piles. In addition, three-dimensional numerical analysis was conducted to analyze the effect of the contraction defect on the pile's resistant behavior. For the pile with the defect of concrete segregation, integrity tests and load transfer measurements showed that the pile strength was reduced by more than 50% in the section of the weak zone having the defects. For the piles that contained the defect of asymmetric contraction of the cross section, the measured strain in the defective section was lower than that in the section without the defect, and three-dimensional numerical analysis showed that the defect increased the axial stress in the section of the defect. Crosshole sonic loggings were conducted before and after static load tests. The difference in the loggings between the prestatic and poststatic load tests indicated the growth of defects as the piles were loaded.
Horizontal Bearing Capacity of Suction Piles in Sand
Authors: Bang S. , Leahy J. C. , Cho Y. , Kwon O.
Published: May 2018

A series of centrifuge model tests was conducted to measure the ultimate horizontal bearing capacity of suction piles. Three different pile lengths were tested in sand. Model piles were laterally loaded at different points along the pile length to evaluate the effect of the loading depth on the ultimate horizontal bearing capacity of suction piles. Two tests were conducted for each loading point. Results from centrifuge model tests were then compared with the analytical predictions to determine the validity of the analytical solution in predicting the ultimate horizontal bearing capacity of rigid suction piles loaded at various depths. Predicted values from the analytical solution compared well with the measured values from the centrifuge model tests.
COM624P-Based Drilled Shaft Torque and Lateral Load Analysis Method
Authors: Byrum Christopher R.
Published: May 2018

Large cantilever-type overhead freeway signs are often supported by a single drilled shaft foundation. Under high wind loads, the cantilever arm and sign panel develop significant torque loading that is distributed to the anchor bolt array cast into the top of the drilled shaft. This torque load is applied to the drilled shaft at approximately the same time as the large lateral load and moment developed by the wind loading. An analysis procedure was used to predict the torque capacity of drilled shaft foundations during the high lateral load condition. The analysis method starts with a typical COM624P p-y–type analysis for the design lateral shear and moment at the anchor bolts. The resulting lateral soil pressures estimated along the drilled shaft sidewalls present during the lateral loading are used to estimate whether voids will be present along the drilled shaft sidewall during torque loading. The estimated drilled shaft sidewall pressures and shear strengths for areas remaining in contact are used to estimate the torque capacity of the foundation. Some applications in different soil profiles are presented. This method was used as part of the development of a standard array of drilled shaft foundations for different soil conditions for standard cantilever-type freeway sign structures used by the Michigan Department of Transportation.
Intelligent Soil Compaction Technology
Authors: Petersen D. Lee , Siekmeier John , Nelson Charles R. , Peterson Ryan L.
Published: May 2018

Intelligent compaction (IC) is a new technique in the U.S. construction market that uses an instrumented compactor to control soil or asphalt compaction in real time. This technology provides one of the first opportunities to apply process control to civil construction. IC is based on the measurement of the mechanical characteristics of the compacted soil, commonly soil stiffness, but other properties are used also. Initiatives in both the United States and Europe started more than 10 years ago and have demonstrated the technical viability of measuring in situ soil stiffness. The measured soil stiffness is used to estimate or compute in situ soil modulus on the basis of assumptions about soil behavior and the interaction between the compaction machine and the soils. IC offers immense potential benefits in embankment, buried structure, and dam and pavement construction. These benefits–-including improved quality, reduced compaction cost, reduced life-cycle cost, and integration of design with construction and pavement performance–-arise from surface-covering documentation and process control of the compaction operation.
Design and Monitoring of an Embankment on Controlled Modulus Columns
Authors: Pearlman Seth L. , Porbaha Ali
Published: May 2018

The controlled modulus columns (CMC) foundation is one technique of ground modification for support of light structures such as highway and railway embankments. In this technique, a specially designed auger, powered by equipment with large torque capacity and high static down thrust, displaces the soil laterally without vibration. During the auger extraction process, a column is developed by pressure grouting to achieve a predetermined stiffness ratio with the surrounding soil. Because of the combined effect of densification and reinforcement, the properties of soft soil are improved because of composite action. The design and monitoring of a column-supported embankment project are presented; 2,193 CMC columns were installed up to a depth of 12.5 m to control settlement. The main challenges were construction on soft ground and the need for an accelerated construction technology for timely delivery of the project. Various alternatives, stability analysis, design considerations, construction challenges, quality control, and monitoring system were evaluated.
Reuse of Fly Ash–Amended Petroleum-Contaminated Soils in Highway Embankments
Authors: Demirkan M. Melih , Seagren Eric A. , Aydilek Ahmet H.
Published: May 2018

Remediation of contaminated soil and groundwater has been an important task for engineers and scientists in recent years. One of the sources of soil and groundwater contamination in the United States is petroleum spills. A laboratory study evaluated the geotechnical engineering properties and environmental suitability of remediated petroleum-contaminated soils for their possible use in highway construction. The laboratory test program included compaction, batch sorption, and long-term column leaching tests. Diesel fuel, naphthalene, and a model nonaqueous phase liquid (NAPL) were used as the pollutants; waste coal fly ash that included high carbon content was used to stabilize the contaminated soils. Compaction test results indicated that the maximum unit weights and optimum liquid contents of the stabilized soils satisfy the limits set for highway embankment construction. The results of the batch-scale adsorption tests conducted on the fly ash revealed that the ash has good naphthalene sorption properties because of the presence of high carbon content in its structure. Column leaching test results suggested that the naphthalene and o-xylene concentrations in the effluents collected from the fly ash–stabilized specimens were lower than those collected from the control specimens (i.e., borrow material). The findings indicate that the high carbon content fly ashes can be good sorptive agents for remediation of petroleum contaminated soils because of their low cost and presence of high carbon content. However, caution should be exercised when the laboratory results are carried to field conditions, because the level of contamination is likely to influence the leaching properties.
Base Reinforcement with Biaxial Geogrid
Authors: Aran Shirwan
Published: May 2018

In 1986 and 1990, the Georgia Department of Transportation constructed two pavement test sites to evaluate the performance of pavements with base reinforced with biaxial geogrid. The evaluations were conducted by a comparison of results from two control sections with no base reinforcement with the results of three test sections with base reinforced by geogrid placed at different depths of the base layers. The test sections also incorporated reduction of pavement section thickness with the use of geogrid. To determine the effectiveness of the geogrid application in regard to pavement cracks, rutting, and deflections, field evaluations were performed on the test and control sections shortly after construction. Construction on SR-155, Henry County, the first test site, ended in 1986; in 1987, the first evaluation was conducted. Annual evaluations were continued up to 1991. At the second test site, East Rome Bypass in Floyd County, construction ended in 1990. Baseline evaluation data were taken soon after construction and in 1991. The tests consisted of deflection measurements, rut measurements, and crack surveys. It was found from these short-term evaluations that the levels of pavement performance for the test and control sections were almost the same. The pavement sections and subgrades at both test site locations were strong and appeared to have a significant effect on the pavement performance. The thinner test sections reinforced with geogrid provided a comparable level of pavement performance to the control sections. Further long-term evaluations were performed in 2005 to determine the performance of the pavements. These evaluations included pavement condition surveys and falling weight deflectometer runs. It was concluded that geogrid test sections with less thickness appeared to perform as well as the typical control sections.
Comparison of Field and Laboratory Pullout Tests on Geosynthetics in Marginal Soils
Authors: Abu-Farsakh Murad Y. , Almohd Izzaldin , Farrag Khalid
Published: May 2018

The increasing use of geosynthetics to reinforce soils in many geotechnical engineering applications requires better evaluation of the soil–geosynthetic interface properties for use in the design and analysis of the different reinforced soil structures. The soil–geosynthetic interaction can be determined from direct shear tests or pullout tests. Until now, most research was focused on investigating the interface properties between geosynthetics and granular materials. Interest has increased in the use of marginal soils as backfill materials in mechanically stabilized earth (MSE) walls and embankments because of the cost-effectiveness of using the available cohesive soils. This strategy requires the evaluation of interaction parameters between geosynthetics and marginal soils. For this purpose, a series of laboratory and field pullout tests was carried out with different types of geosynthetic reinforcements in marginal silty clay soil of medium plasticity. Four types of geogrids and three types of geotextiles were used in this study. Laboratory and field pullout tests were compared. The coefficient of interaction ( Ci) between geosynthetics and cohesive backfill, the variation of pullout design parameters ( F*, α) with overburden depth, and the shear stress distribution along the reinforcement specimen also were evaluated.
Influence of Soil Strength on Optimal Embedment Depth of Geosynthetic Reinforcement Layer in Granular-Reinforced Foundations
Authors: Hatami Kianoosh , Raymond Gerald P.
Published: May 2018

The effect of soil friction angle value on the optimal embedment depth of a single geosynthetic reinforcement layer in granular foundations was investigated with a numeric simulation approach. The numeric model was validated against the measured results of reduced-scale plane strain model foundations tested with two footing width sizes. The model foundations were constructed with gravel-sized round aggregates and were subjected to the concentrated vertical load of shallow footings analogous to a track–ballast system. After the validation of the numeric model, a series of parametric analyses was carried out with an idealized, full-scale foundation model to investigate the dependency of the optimal reinforcement embedment depth on the soil friction angle value. The optimal reinforcement depth in field-scale reinforced foundations under strip footings is between 10% and 15% of footing width, depending on the site soil friction angle value. The optimal reinforcement depth is found to be slightly closer to the footing in a weaker soil. The range of optimum reinforcement depth values obtained from this study is shallower than those suggested in some earlier studies using reduced-scale model foundations. Optimum reinforcement depth values obtained merely on the basis of the results of reduced-scale tests may be overestimated because of the unrealistically low overburden pressure compared with the field-scale foundations.
Integration of Information and Automation Technologies in Bridge Engineering and Management
Authors: Chen Stuart S. , Shirolé Arun M.
Published: May 2018

The current U.S. practice of information transfer during the bridge design, fabrication, construction, and operation processes is fragmented. These processes involve repeated manual transcription of data, which is error prone; approvals (e.g., of shop drawings) that are time-consuming; and formats that beg for standardization to facilitate electronic information transfer. Without such standards, electronic information exchange is impossible. This paper surveys the shortcomings of current piecemeal applications of information and automation technologies. It then explores the promise of parametric three-dimensional bridge information modeling as an enabling technology for accelerating the design and delivery of bridges and articulates aspects of the envisioned accelerated bridge delivery process for two purposes: to provide a glimpse of current technologies available to streamline the process of bridge delivery and to articulate anticipated advances that can be expected to facilitate accelerated bridge delivery. In lieu of a complete industrywide modeling of bridge information in a standardized format, savvy bridge design–build teams can be expected to obtain a competitive advantage by integration of computer-aided design, computer-aided engineering, and computer-integrated manufacturing, which will result in rapid and better-quality project delivery and subsequent cost-effective life-cycle management. As a result, all three fundamental objectives of bridge delivery would be expected to be attained: higher quality, faster delivery, and greater economy.
Analysis of Masonry Bridges
Authors: Mamaghani Iraj H. P.
Published: May 2018

Masonry bridges are composed of a finite number of distinct interacting blocks that have a length scale relatively comparable to the structure of interest. Therefore, they are ideal candidates for modeling as discrete systems instead of modeling as continuum systems. The discrete finite element method (DFEM) developed by the author to model discontinuum media consisting of blocks of arbitrary shapes is adopted in the static and dynamic analyses of masonry bridges. The developed DFEM is based on the principles of the FEM that incorporate contact elements. DFEM considers blocks as subdomains and represents them by solid elements. Contact elements, which are far superior to joint or interface elements, are used to model the block interactions, such as sliding or separation. In this study, the DFEM is briefly reviewed. Through some typical illustrative examples, the applicability of the DFEM to analysis of masonry arch bridges is examined and discussed. It is shown that the DFEM has the potential to become a useful tool for researchers and practicing engineers in designing, analyzing, and studying behavior of masonry bridges under static and dynamic loading.
Influence of Residual Damage on Fatigue Performance of Heat-Straightened Steel Bridge Girders
Authors: Connor Robert J. , Urban Michael J.
Published: May 2018

Damage to highway bridge members can occur when vehicles strike a bridge member. The damage, which occurs at high strain rates, results in significant plastic deformation of the member. Heat straightening along with mechanical techniques, such as jacking or pressing, of damaged members has been demonstrated to be an effective, accurate, and cost-efficient repair technique when applied correctly. Fortunately, significant research efforts over the past 20 years have led to the development of appropriate techniques to repair severely damaged members. Less certain, however, is the fatigue and fracture performance of heat-straightened members. This paper reports on the current status of NCHRP Project 10-63, Heat-Straightening Repair of Damaged Steel Bridge Girders: Fatigue and Fracture Performance. The initial results of the study suggest that there is no degradation in the fatigue resistance of damaged, heat-straightened members as long as all nicks, gouges, and other defects are removed and the beam is returned to its initial undamaged geometry. It has been found that in the presence of residual geometric damage, the live load stresses near the impact location can be significantly altered and local stresses at fatigue sensitive details may be much higher than determined through traditional nominal stress calculations. The FHWA manual of standard practice for heat-straightening repair of steel bridges does not address this issue, and its use can therefore result in unconservative estimates of remaining fatigue life in repaired girders in some instances. A preliminary method to quantify the effects of residual damage and some of the general findings of the research are presented in this paper.
Rapid Replacement of a Movable Steel Railway Bridge
Authors: Unsworth John F. , Brown Christian
Published: May 2018

Railway bridges must be replaced rapidly to avoid detrimental effects on the operation of the railway. Detour routes are sometimes not available and often not an economical option. This paper describes the planning and techniques used in the rapid replacement of a movable steel railway bridge with minimal interruption to railway and marine traffic.
Field Testing Serviceability Performance of Missouri's First High-Performance Steel Bridge
Authors: Barker Michael G. , Barth Karl E.
Published: May 2018

The Missouri Department of Transportation (MoDOT) built the state's first high-performance steel (HPS) bridge in 2002. MoDOT Bridge A6101 uses HPS 70W in the design of the 138-ft–138-ft two-span, five-girder bridge. Design calculations show that using HPS in only the highly stressed regions (hybrid design) led to a superstructure steel weight savings of nearly 17% and an estimated cost savings of approximately 11% compared with building a conventional 50-ksi (50W) bridge. As in many other progressive states, in Missouri the future of HPS is promising. HPS 70W is a superior steel that can lead to more economical bridges than can conventional 50-ksi designs. However, with the higher-strength steel, sections become smaller and deflections increase. Many states, including Missouri, impose deflection serviceability limits that are stricter than those dictated by AASHTO design provisions. The researchers worked with MoDOT to instrument, field test, analyze, and evaluate the performance of completed Bridge A6101. Serviceability field testing confirmed that MoDOT's, and thus many states’, serviceability criteria are conservative compared with those of AASHTO. The conservative serviceability procedures used by some states will cause many HPS designs to be controlled by deflection, as A6101 was, instead of strength parameters. When deflection controls the design, there is no benefit in using higher-strength materials, and the weight and cost savings will not be realized. This paper presents the serviceability testing and serviceability performance of Bridge A6101.
Optimized Load and Resistance Factor Design of Prestressed I-Girder Bridge Superstructures with High-Strength Concrete
Authors: Mirtalaei S. Kamal
Published: May 2018

The use of the AASHTO LRFD Bridge Design Specifications will be mandatory for all departments of transportation (DOTs) in the United States for federally funded projects beginning in October 2007. Several states, including Arizona, have already started developing their bridge design specifications, defining pilot projects to be designed according to load and resistance factor (LRFD) specifications. In addition to implementing the new specifications, most DOTs will make wide use of high-performance–high-strength concrete. This paper presents an investigation of girder–slab bridges that were designed in accordance with both LRFD and standard AASHTO bridge design specifications and that used conventional and high-strength concrete (HSC). Major changes in LRFD design methodologies are discussed, and a general comparison between the standard AASHTO specifications and the LRFD specifications is made. A computer program was specifically developed for the analysis, design, and cost evaluation of these superstructure types. This program is capable of performing calculations for both LRFD and standard methods. Detailed observations were made of these two design methods to compare the relative value of their analysis and design features and their cost. Cost evaluations of these bridge superstructures with different geometrical configurations (girder type, spacing, etc.) made it possible to obtain practical design charts for the optimum girder type or girder spacing. Several aspects of HSC were studied to determine the effect of concrete strength on design variables. The effect of concrete strength in flexural members is more pronounced in prestressed concrete than in reinforced concrete. The use of HSC enabled significantly longer span lengths, girder spacing, or both, which is not practical with normal strength concrete. A detailed study and comparison was done on different AASHTO methods for concrete deck slab design.
Design of Hammerhead Bent Cap to AASHTO Load and Resistance Factor Design Specifications
Authors: Brown Michael D. , Bayrak Oguzhan
Published: May 2018

The design of a single hammerhead bent cap is presented. The design is performed through the use of both the strut-and-tie models and the sectional design procedures in the AASHTO LRFD [Load and Resistance Factor Design] Bridge Design Specifications. Two truss models are used to design the bent cap. The two trusses result in identical shear reinforcement. However, the use of sectional design procedures for this bent cap requires approximately one-half the amount of shear reinforcement. The results of a strain energy analysis indicate that simple trusses with a direct strut between the load point and the support point best model the actual load-carrying mechanism in the bent caps.
Static and Dynamic Testing of a Concrete T-Beam Bridge before and after Carbon Fiber–Reinforced Polymer Retrofit
Authors: Catbas F. Necati , Grimmelsman Kirk A. , Ciloglu S. Korhan , Burgos-Gil Ildefonso , Coll-Borgo Manuel
Published: May 2018

This paper summarizes the design and execution of field studies to improve the performance of a deteriorated bridge through the use of carbon fiber–reinforced polymer (CFRP) material. The objective of the CFRP retrofit was to extend the life of Bridge 2028 in Cayey, Puerto Rico, by increasing its load rating. Field testing before and after the retrofit was performed to evaluate objectively improvement in load capacity and stiffness. The field testing program included both static load tests and dynamic tests. The first set of field tests was conducted in November 2002 to capture baseline bridge performance characteristics before the retrofit. The CFRP retrofit was installed in October 2003, and a second set of nearly identical field tests was performed in August 2004. The test results indicated that the retrofit increased the bending stiffness of the bridge by 15% and decreased the tensile strains in the bottom rebars of the concrete T-beams by about 13%. Furthermore, the maximum rebar strains under a heavy truck load case were only 10% of the yield strength after the retrofit. The change in stiffness determined from static deflection measurements was well correlated with the stiffness change determined from the dynamic tests. The field testing program showed that the CFRP retrofit was successful in improving the mechanical behavior of the bridge. The long-term performance and durability of the CFRP retrofit could be affected by a number of parameters such as local environmental conditions. The field testing program is to be periodically repeated; alternatively, a continuous monitoring program could be implemented to evaluate objectively the long-term performance and durability of the CFRP retrofit.
Field and Laboratory Testing of Precast Concrete Channel Bridges
Authors: Wipf Terry J. , Klaiber F. Wayne , Ingersoll J. Scott , Wood Douglas L.
Published: May 2018

The precast channel bridge (PCB) was commonly constructed on Iowa's secondary roads approximately 40 years ago. Each PCB span consists of eight to 10 simply supported precast panels ranging in length from 19 to 36 ft. The panels resemble a steel channel in cross section; the web is orientated horizontally to form the roadway deck, and the vertical legs act as shallow beams. Bundled bars in each leg are used for flexural reinforcement. Many of the approximately 600 PCBs in Iowa show signs of significant deterioration. Typical deterioration consists of spalled concrete cover and corrosion of the bundled primary reinforcement. The objective of this research was to assess the structural sufficiency of the deteriorated PCBs through field and laboratory testing. Four deteriorated PCBs were instrumented with strain gauges to measure strains in both the concrete and the reinforcing steel and with transducers to measure vertical deflections. Responses from loaded trucks were recorded and analyzed. Test results revealed that all measured strains and corresponding stresses were well within acceptable limits. Likewise, measured deflections remain well below the maximum recommended AASHTO values. Laboratory testing consisted of loading 12 deteriorated panels to failure in a four-point bending arrangement as well as testing a four-panel model bridge. Although all panels exhibited significant deflection before failure, the experimental capacity of 11 of the panels exceeded their theoretical capacity. Service tests and an ultimate strength test were performed on the laboratory bridge model to determine the effect of various keyway connection configurations.
Field-Measured Natural Frequencies of Delaware Memorial Bridge
Authors: Dusseau Ralph Alan , Jones John R. , Ramachandran Ravi P. , Sun Carlos C. , Arr Glenn
Published: May 2018

The Delaware Memorial Bridge is a major suspension bridge that is critical to the tristate region of northern Delaware, southern New Jersey, and southeastern Pennsylvania. The Delaware Memorial Bridge consists of two nearly identical suspension bridges (hence, the nickname Twin Spans) that cross the Delaware River from southern New Jersey to northern Delaware. Field ambient vibration measurements of Structures 1 and 2 of the Delaware Memorial Bridge were conducted in June 2001 and September 2003. These measurements were used to derive the natural frequencies and modes of vibration for these structures. These field-measured frequencies and modes were then compared with each other and with computer-generated natural frequencies and modes of vibration derived for Structure 2 of the Delaware Memorial Bridge in 1997. Specifically, the 2001 seismometer-generated results for Structure 1 were compared with the 2003 accelerometer-generated results for Structure 1; the 2003 field-measured results for Structure 2 were compared with the 2003 field-measured results for Structure 1; and the 2003 field-measured results for Structure 2 were compared with the 1997 computer-generated results for Structure 2. Overall, these three types of comparisons indicated relatively good correlation for transverse motion but only fair correlation for longitudinal and vertical motion.
New Inspection and Risk Assessment Methods for Metal Highway Culverts in Ohio
Authors: Masada Teruhisa , Sargand Shad M. , Tarawneh Bashar , Mitchell Gayle F. , Gruver Doug
Published: May 2018

This paper first describes Ohio's new statewide culvert management program, which aimed to reduce the risk of structural failure of culverts that serve major highways. The paper next describes a research project conducted by the Ohio Research Institute for Transportation and the Environment (ORITE) research team at Ohio University to validate the effectiveness of the approaches outlined in the new program. The new culvert program is supported by high-resolution field inspection and rating procedures for concrete, metal, and thermo-plastic culverts. This paper focuses on the metal culvert components of the research project. The new field inspection procedure for metal culverts was applied at 25 sites to detect problems common to many metal culvert sites in Ohio. The data produced during the field inspection phase were analyzed statistically to evaluate the effectiveness of the new procedure and to verify the findings made by the previous study about the conditions of the metal culverts that serve Ohio's major highways. Finally, the paper presents a risk assessment method proposed by the ORITE researchers for computing and adjusting the structural rating of the metal culvert and recommends a course of action.
Changes in Hydraulic Roughness Coefficients for Circumferentially Strained M294 Pipe
Authors: Tullis Blake P. , Barfuss Steven L. , Christensen Ryan T.
Published: May 2018

When a culvert or storm drainage pipe is being sized on the basis of discharge capacity requirements, knowledge of the hydraulic roughness of the pipe is required. Hydraulic roughness is typically influenced by both the roughness of the pipe material and the inside pipe wall profile (e.g., smooth, corrugated, etc.). When subjected to external loads associated with field installations (e.g., backfill, compaction, etc.), the inside wall profile of thermal-plastic pipe products, like high-density polyethylene (HDPE) M294 drainage pipe, often changes due to circumferential strain. As lined HDPE pipe strains circumferentially, the structural external ribs reduce in diameter, which causes the inside liner to develop a longitudinal corrugated wall profile. Variations in the hydraulic roughness of M294 Type S drainage pipe with 24-in. (0.61-m) diameter that were based on external circumferential strain rates ranging from approximately 0 to 2.4% were identified in this study, conducted at the Utah Water Research Laboratory, Utah State University. The circumferentially strained pipe wall geometries of four in-service M294 Type S drainage pipes with 24-in. (0.61-m) diameter were measured and compared with the laboratory pipe conditions. The results of this study were also compared with a previously published predictive method for determining Manning's n values on the basis of corrugation depth and pipe diameter.
Limiting Slurry Pressures to Control Hydraulic Fracturing in Directional Drilling Operations in Purely Cohesive Soil
Authors: Kennedy Mathew J. , Skinner Graeme D. , Moore Ian D.
Published: May 2018

Hydraulic fracturing during horizontal directional drilling can permit drilling mud to travel to the ground surface, to collect under overlying pavements, or to be released into the riverbed during river crossings. These events can decrease drilling efficiency, damage adjacent infrastructure, and cause environmental damage. Current design equations for maximum drilling pressure focus on shear failure around the borehole drilled to house the new pipe. The present research examines, instead, the potential for tensile fracture of cohesive soils surrounding the borehole. Two-dimensional nonlinear finite element modeling is used to study the effectiveness of closed-form solutions for calculation of the drilling slurry pressures that fracture the surrounding soil. Tangential stresses are calculated for a borehole with a 0.2-m diameter in an undrained clay soil with various K0 values, construction depths, and drilling slurry pressures. Elastic plate theory is found to provide effective values of ( a) tangential crown and spring line stresses when the soil responds elastically and ( b) the decreases in tangential crown stress that occur as drilling slurry pressures increase. Closed-form plasticity solutions provide good values of tangential stresses once the soil yields. Following yield, increases in mud pressure result in increases in tangential stress, so hydraulic fracture from tension is no longer an issue. The study indicates that mud loss in low-strength clays or those with K0 close to unity is most likely the result of unconfined plastic flow (blowout). Mud loss for stiff clays and those with other K0 values is more likely the result of tensile fracture.
Flexural Resistance Models for Concrete Decks Reinforced with Fiber-Reinforced Polymer Bars
Authors: Okeil Ayman M. , Kulkarni Sujata
Published: May 2018

A major portion of maintenance budgets in the United States is usually directed to deck replacement on the aging population of bridges. Concrete deck deterioration, which is mainly due to corrosion of steel reinforcing bars, often takes place before the design life of the bridge is achieved. Fiber-reinforced polymer (FRP) bars offer a tensile reinforcement alternative that would eliminate corrosion-related problems. Estimation of the flexural capacity of concrete elements reinforced with FRP bars relies on the same concepts of equilibrium and compatibility used for other materials. Incorporation of these concepts in a load and resistance factor design format requires a reliability study and calibration of the new system. This paper presents statistically derived resistance models for concrete decks reinforced with FRP bars. The resistance models are based on a detailed layered-section analysis that takes into account the nonlinearities of the materials. A wide range of parameters was considered, including various thicknesses, concrete strengths, and reinforcement ratios. The results from this research will be used in a calibration study that will provide resistance factors suitable for flexure design of bridge decks reinforced with FRP bars.
Seismic Performance of Reinforced Concrete Bridge Substructure Encased in Fiber Composite Tubes
Authors: Zhu Zhenyu , Mirmiran Amir , Saiidi M. Saiid
Published: May 2018

Recent cyclic tests in the United States, China, and Japan have shown that fiber-reinforced polymer (FRP) tubes can effectively replace spiral reinforcement in reinforced concrete (RC) columns. This study was undertaken to advance the current state of the art for concrete-filled FRP tubes (CFFTs) by comparing their seismic performance with that of conventional RC bridge pier columns at the sectional, member, and bridge system levels. A nonlinear finite element model was developed for a bridge case study. Because FRP has a lower rupture strain than steel spiral and because of its linear elastic response, a CFFT section shows less ductility than an RC section. However, at the member level, a CFFT column distinctly outperforms its RC counterpart, with almost twice the base shear capacity and more than three times the lateral drift capacity. This phenomenon was attributed to the effective role of the FRP tube in extending the plastic hinge zone of the column well beyond its typical range in conventional RC columns. The implication of this behavior was shown through a seismic simulation of the entire bridge under a major historical shake with varying levels of magnified ground acceleration. The simulation showed the CFFT substructure to suffer moderate damage while maintaining structural integrity compared with the RC substructure, which suffered severe and irreparable damage.
Sequential Logit Dynamic Travel Demand Model and Its Transferability
Authors: Fu Haoqiang , Wilmot Chester G. , Baker Earl J.
Published: May 2018

A dynamic hurricane evacuation travel demand model was estimated by using sequential logit with the data from Hurricane Floyd in South Carolina. The model was estimated on a random sample of 75% of the observations and applied to the remaining 25% as a test. In the test data, a total of 241 evacuations were predicted when 246 were observed, and the model estimated the number of evacuations in each 2-h period over 4 days with a root-mean-square error of 2.79 evacuations. Evacuation orders were modeled as a time-dependent variable. This significantly enhanced model performance over that achieved with evacuation orders as a stationary variable in previous work and provided the capability to analyze the impact of the type and timing of evacuation orders. That capability permits analyzing staged evacuation, in which areas are directed to evacuate in a sequence that optimizes network use. A model estimated on Hurricane Floyd evacuation data was transferred to Southeast Louisiana; its predictions were similar to evacuation behavior observed during Hurricane Andrew. With updating of the alternative specific constant of the transferred model to ensure the correct prediction of the total number of evacuations, the model predicted evacuation with a root-mean-square error of 4.53 evacuations per 6-h period. It was discovered that applying the same distance function to the two different hurricanes was a major source of error in model transfer. The representation of distance and its interactions with other variables need to be investigated further. The procedures and the information needed for model update warrant further study.