Journal of Performance of Constructed Facilities

This paper examines the behavior of steel moment frames under the scenario of a column removal at their ground floor. Through a material and geometric nonlinear analysis, this work evaluates a global loss-of-stability progressive collapse mode for steel frames. This collapse mode appears while the components of the structure remain in the elastic zone and involves the loss of stability of the structure. The results of the analysis show that after the removal of the column, the appearance of limited fiber yielding of the components of the structure can progressively lead to the loss of stability and the collapse of the entire structure. The main contribution is the identification of the global loss-of-stability progressive collapse mode through the production of pushdown curves. The work focuses on the need to analyze a structural system as a whole, rather than as individual components, during a progressive collapse analysis.

Any deficiency in excavation design or construction could lead to excessively large retaining wall and ground displacements, usually accompanied by damage to adjacent structures or facilities. This paper documents a case history of a small air shaft excavation in Shanghai soft clay. Its maximum lateral wall displacement and ground settlement were twice and three times the local deformation control criteria and 3 and 14 times those of one adjacent air shaft excavation featuring similar subsurface conditions, geometric size, and supporting system. To identify probable causes pertaining to its poor performance, a comprehensive investigation was carried out in both design (propping element, supporting system stiffness, wall penetration ratio, and jet grouting of basal soils) and construction (excavation duration, excavation width, exposed wall length, and management of heavy-duty truck and stockpile of construction materials). The investigations show that there were several major contributory factors, among them were adoption of cast concrete struts at deep excavation level, removal of underlying jet-grouted soil layer before fully curing of concrete strut, and passing over of trucks and stockpiling of construction materials nearby. On the basis of the analysis of its field instrumentation data and comparison with the adjacent air shaft excavation and another four subway station excavations, adverse effects of the identified contributory factors were quantified, valuable lessons were learned, and graphical solutions for estimating effects of excavation width and exposed wall length on lateral wall displacement and predicting diaphragm walling-induced ground settlement were derived.

Alkali-silica reaction (ASR) is a persistent issue and has evaded eradication for nearly 80 years. The problem stems from a lack of standardized testing of aggregates. Cases occur when changes in material properties lead to potentially reactive aggregates reacting with higher alkali cements. A research program was established at the University of Arkansas to investigate cases of ASR, which occurred in combination with previously inert aggregates. In addition, locally available fly ashes were evaluated to determine replacement rates required to minimize the risk of ASR. A field monitoring program was established to evaluate deterioration mechanisms and mitigation measures. A concrete barrier wall located near the University of Arkansas was diagnosed with ASR that had considerable variation in the damage between sections of the wall. Deterioration ranges from minimal visible deterioration to severe damage or complete failure. The testing program reveals that certain aggregates that were previously deemed safe for use in concrete reacted deleteriously when other material properties changed.

The seismic vulnerability analysis of a strategic building is presented in this paper. A refined finite-element model was set up on the basis of available experimental results, and updated on the basis of new experimental analyses on materials and structure. As demonstrated by an experimental vibration analysis, the structural behavior is influenced very much by the irregularity of the building and the presence of an adjacent building with no seismic joint. The results indicate a high vulnerability of the building to seismic actions, and the inadequacy of the pile foundation—for which a specific nonlinear analysis was performed—to support horizontal seismic loads. A retrofit intervention, based on the insertion of a seismic isolation system and the realization of a seismic joint with the adjacent building, was proposed, which allows the reduction of horizontal forces in the piles and the torsional movements of the structure.

The seismic behaviors of different steel beam-to-column moment connections have been fully described by many researchers. Some researchers focus on their progressive collapse resistances by static and rate-independent analyses. However, the influence of strain-rate effect should not be neglected when the main column is removed instantaneously in a progressive collapse analysis. In this paper, the progressive collapse performances of typical steel moment connections with different seismic details, including the welded unreinforced flange-bolted web (WUFB), the welded cover plated flange (WCPF), and the reduced beam section (RBS) connections, are studied by numerical analyses. The rate-dependent stress–strain curves of Q345 steel were obtained from a high-speed tensile machine first. Static push-down analyses were applied to investigate the progressive collapse resistances of beam-to-column connections with different seismic details. The numerical results show that the WCPF connection has the best progressive collapse resistance owing to its strong rotational and bond capacity. For the RBS connection, the reduced beam section contributes to the increased rotational capacity but limits the improvement of its ultimate capacity, especially its dynamic capacity. Strain-rate effects show different influences on the dynamic behaviors of beam-to-column connections. The WUFB and RBS connections are more sensitive to strain-rate effects than the WCPF connection. The bearing and deformation capacities of WUFB and RBS connections increase by more than 40% and 30%, respectively, when the strain-rate effect is considered.

While the transportation system of the United States rapidly ages and expands, there is increasing demand for the demolition, replacement, modification, or rehabilitation of existing bridges; all of these actions require some degree of engineered deconstruction. In a 2013 report on American infrastructure a large number of bridges surveyed were reported to be structurally deficient or functionally obsolete, and many of the existing bridges have exceeded their 50-year design life. Although highway bridges have been deconstructed around the world for generations, there are few publications on the structural engineering aspects of the deconstruction process. This paper aims to shed light on the general nonexplosive deconstruction process by presenting aspects of a three-span continuous steel girder highway bridge example. General sequence, equipment, methods, economy, and engineering are discussed. The authors also focus on the role of structural engineers, as they can be a key factor in safe and economical deconstruction.

In the summer of 2015, the existing ceramic cladding of the Girasol Building in Madrid went through an inspection campaign that left all underlying occurrences of detachment exposed. The community of neighbors then decided to renew the façade, therefore marking the end of the service life (SL) of the cladding. A visual assessment of the façade was thus made in order to quantify its overall condition after 49 years of SL. These data are used to provide real life feedback and discuss existing methods of SL estimation. The information gathered confirms that 50 years (or 100 aging cycles) are accurate estimations for the SL of ceramic claddings for a 20% level of degradation. Conclusions are also reached regarding the relationship between SL, threshold limits, and their dependency on human decision making processes.

This paper proposes a methodology for mapping structural damage onto building frames due to exterior blast threats for use in a threat-dependent progressive collapse assessment. The proposed approach contrasts with current practice, which typically relies on a threat-independent approach for progressive collapse analysis. Damage is mapped to the structure based on the calculated response of the discrete structural components (particularly the columns) to a blast-induced pressure time history. Contours of structural damage can then be mapped over the building face for discrete combinations of charges and standoffs. For a prototype reinforced concrete building frame, calculated distributions of damage for conventional explosive threats suggest that the current state-of-practice approach (in which damage is represented with a single column removal) may not constitute a generally conservative strategy for progress collapse-resistant design. The proposed framework can be used to determine standoff distances needed to reduce progressive multicolumn failure scenarios in building frames for high-risk facilities and can be used as input for a progressive collapse assessment of these frames.

The performance of a structured-walled, hybrid plastic-steel pipe, installed under standard and substandard conditions, was monitored in field tests. Sections of steel-reinforced, high-density polyethylene resin pipe, with inner diameter of 1.02 m and outer diameter of 1.12 m were installed at two test sites. In the first, the standard installation site, the pipe section was placed in a 2.0-m-deep, 2.1-m-wide trench, following subgrade compaction, on a compacted sand bedding layer. The trench was backfilled with layers of compacted sand and crushed stone to form a base to 0.8 m above the crown. In the second site, neither trench base nor bedding and fill materials were compacted. The trench consisted of a central section 2 m wide, and end sections 1.5 m wide; one-half of the length was backfilled with in situ, clay clods and the other with sand, both overlain by a layer of compacted base course to 0.5 m above the crown. Pipe deformations, monitored during installation and trafficking, and dynamic cone penetration (DCP) tests, performed in the backfill at various stages, are reported and discussed.

Owing to its light self-weight, low heat capacity and large thermal expansion coefficient, the application of the curved steel box girder bridge with small and medium spans has gained popularity for the construction of urban infrastructure. However, sun exposure could easily increase the maximum temperature difference at the bottom of steel box beam by 25°C. With the effect of nonuniform temperature field and overloaded vehicles, the edge inside the curved steel box girder bridge may be separated from the remaining structure, resulting in overturning. Thus, more attention needs to be paid in order to prevent the separation. In this paper, an overturning resistance analysis of a three-span curved steel box girder bridge located in Hangzhou, China was performed. A model was proposed based on the measurement of temperature field to the steel box girder. The separating displacement due to temperature variations was predicted and verified by the measurement results. As a result, changes in supporting reactions due to the effect of the nonlinear temperature field and self-weight and offset vehicle load were determined, and the overturning stability of the bridge was analyzed via the trial and error method. The balance weight method was employed to diminish the risk of overturning of bridges. Finally, the method proposed in this paper was applied to a bridge under construction, which results in an increase in stability safety factor from 0.63 to 2.58.

This study focuses in the impact of vehicle speed, vehicle type, and transverse rumble strip (TRS) design on the sound pressure level perceived by drivers when they traverse a TRS. TRSs are commonly installed on approaches to toll plazas and at intersections, etc. The ability of a TRS to capture a driver’s attention is directly related to the magnitude of the sound and vibration. However, the traffic noise generated by TRS creates a problem for adjacent residences and businesses near the roadway. Thus, the aim of this study is to quantify the level of traffic noise and verify the effects of TRS shapes. The research team measured the exterior noise, inner noise, and vibration generated by three types of vehicles (sedan, minivan, and truck) traveling over four types of transverse rumble strip applications (Types A, B, C, and D) with speed range between 40 and $100\mathrm{km}/\mathrm{h}$. In general, the increase in the exterior noise generated was greater at $100\mathrm{km}/\mathrm{h}$ than at $40\mathrm{km}/\mathrm{h}$ and lower for a sedan than for a truck. Type A generated the highest exterior noise and Type C generated the highest inner noise. The sound level clearly changed according to TRS dimension such as shape, width, and length, etc. Type C showed the best performance with a lower sound pressure level, effective ability to alert the driver, and reduced complaints from adjacent residents after implementation on a highway road in Korea.

The paper describes a probabilistic risk assessment model to identify the risks associated with vehicle-borne improvised explosive device (VBIED) attacks to large federal government buildings in the United States. Probability of terrorist threat, hazard, damage, fatality, and economic and social loss for progressive collapse are modeled as stochastic variables. It was found that the existing annual fatality risk for building occupants is lower than acceptable risk criteria, and that progressive collapse is an exceedingly rare event in Western countries. A performance-based design using cost-benefit analysis of U.S. design provisions to mitigate against progressive collapse showed that these design measures only becomes cost-effective when the threat likelihood is a very high 1 in 1,000 per building per year. However, such provisions are more likely to be cost-effective in regions of high seismicity due to a lower cost premium.

In recent history, a number of State Departments of Transportation have looked at providing safer driving conditions on bridges. One improvement method is placing high friction overlays on bridge decks. This study analyzed crash data to evaluate the performance of high friction overlays in reducing crashes. This study was completed by analyzing 10 years of data for nine bridges encompassing four different proprietary overlay systems. Within one of the overlay systems, three different aggregate types were also compared. Crash characteristics analyzed included the crash time, weather conditions, bridge surface conditions, average annual daily traffic, and severity of crashes. This study is part of a comprehensive study that includes extensive field evaluation and comparative performance analysis between different systems to evaluate their effectiveness on bridge decks in Minnesota. While the data presented herein is from bridge sites located in Minnesota, the findings apply to most of the northern tier states in the United States as well as other countries with colder climatic conditions. The analysis of data suggests that although there is a reducing trend in overall number of crashes; a reduction in crashes on bridges cannot be completely attributed to the use of high friction overlays. Furthermore, the presence of high friction overlays are unable to play a role in winter crash prevention. Thus this study shows that forensic evaluation of accident data does not support commonly anticipated crash reduction benefit of high friction overlays.

Forensic investigations were conducted to identify the causes of longitudinal cracking (LC) of a newly constructed highway. The case-study highway was built with a composite pavement system and is located in a semiarid region north of the equator in Africa. During these investigations, several tests were performed, such as a visual survey of cracks, nondestructive tests, and coring. Long-term observations of soil movements and crack growth were executed. The results showed that the main reasons for surface cracking were (1) use of clayey soils as filling material, and (2) the region’s climate. Such conditions led to a cycle of nonuniform swelling-shrinkage of embankment soil, which resulted in failure of the treated base and the beginning of a well-defined cracking mechanism. The results of this investigation will allow suggestions to be proposed for immediate improvement of the zone against most defects and to implement remedial solutions for other parts.

Protective interventions are often needed to protect sensitive buildings from ground deformation induced by tunneling. This paper evaluates the effectiveness of underground jet-grouted partition wall in mitigating the effects of shield-tunnel construction on existing piled structures by means of numerical analysis and field monitoring. It is shown that the tunneling-induced displacements field can be modified by the underground partition wall in different ways depending on the combination of influential factors, such as wall stiffness, partition range angle, and insert depth below the tunnel invert. The results also indicate that the presence of the partition wall can relieve the existing piles from suffering from differential displacement, thereby improving the mechanical performance of pile–pier interaction. The reasonable agreement found between the observed field measurements and the numerical results demonstrates that underground jet-grouted partition wall can serve as an effective recourse of ground movement control given the need of tunneling nearby piled structures.

Roofs are one of the construction elements most directly affected by external climate agents and most sensitive to deficiencies caused by errors or lack of maintenance. In this study, 65 construction projects of tile-covered pitched roofs were analyzed, studying the deficiencies found during the execution process, in terms of whether or not the project’s design had been previously controlled. A total of 380 deficiencies were detected, which amounts to an average of 5.85 deficiencies per project studied. Each of these deficiencies was assigned to a location group and assigned a level of importance (as evaluated by peers) to estimate the possible damage it might lead to in the future.

In this research, external retrofit of reinforced concrete (RC) buildings, especially the ones located in Turkey, was studied. Most of Turkey’s population live in an active seismic zone where frequent earthquakes are experienced. Turkey’s existing residential building stock consists mainly of reinforced concrete buildings that are prone to earthquake damage because of a lack of lateral strength. Therefore, a fast and feasible shear retrofit method for these buildings is crucial. In this study, three six-story prototype RC buildings were created to study the effectiveness of external shear retrofit with and without the inclusion of window openings, constructed at building corners. As always desired, this retrofit method was shown to be fast to apply and its construction requires minor damage on the building. The three-dimensional (3D) finite-element model of the building was analyzed nonlinearly by a commercially available software package. The modeling of concrete material as well as embedded steel reinforcement was proved to be satisfactory by calibrating them with three $1/3$-scaled RC frame retrofit experiments existing in the literature. The effect of corner shear walls with and without window openings on the base shear capacity and lateral stiffness was assessed comparing with the bare frame. The shear contributions of columns and shear walls for the model buildings were also compared. Considerable amount of capacity increase in base shear and stiffness was achieved by the addition of external shear walls, even with the inclusion of window openings.

Various characteristics of a structure influence its response when subjected to a blast load. This has important implications for survivability and resistance to progressive collapse. In this study, the effect of the type of lateral load resisting system on reinforced concrete (RC) building resistance to progressive collapse when exposed to blast load was examined. Fourteen different reinforced concrete structures were considered for analysis, with five structures designed as moment-resisting frames and nine designed as shear wall systems. Buildings with 3, 6, and 10 stories with 3-, 4-, and 5-bay symmetric configurations were considered. The structures were exposed to external and internal charges, whereas the nonlinear, transient dynamic analysis of collapse behavior was investigated with a finite-element-based approach, the applied element method (AEM). The results show that the shear-wall structures and structures larger in height and plan generally provide greatest resistance to blast damage and progressive collapse.

Adjacent box-girder bridges have become a popular choice as they can be constructed quickly, easily, and economically. In spite of their good performance during many years of service, one major problem has been recurrent longitudinal cracking of the grout material in the shear key. A combination of shear keys and transverse posttensioning (TPT) ties in such kind of bridges is typically used to connect the bridge girders together so that they would behave as a single integrated unit. However, information regarding the contribution of the TPT tie bars on load transfer between adjacent box girders is limited. In this study, a single-span precast prestressed concrete adjacent box-girder bridge was instrumented and monitored to study the effect of TPT tie bars on load transfer mechanism and overall bridge behavior under static and dynamic truck loads. Two sets of instruments were installed in the girders and tie bars during and after the construction of the bridge. A good correlation was achieved between experimental measurements and results from a three-dimensional (3D) finite element (FE) model. An in-depth analysis of the data indicated that, under static loads, there was a contribution from the tie bars to the load-transfer mechanism between the girders. The maximum measured relative displacement at the joints was below the damage limits. Under dynamic loading, the dynamic load allowance (DLA) obtained was higher than that of the standard design procedure of bridges. Based on the FE analysis, the relative displacement of the joints and the load distribution between the girders are influenced by the initial TPT force applied during construction. The level of stresses generated in the concrete girders and shear keys under truck load was not high enough to cause damage.

Earthquake-induced liquefaction is a major threat to the safety of earth embankments. This paper presents an experiment-based safety assessment of antiliquefaction performance of a constructed reservoir embankment. This reservoir is a major project constructed in the middle of a tidal estuary in 2007 and supplies nearly half of the raw water for the Shanghai, China. The embankment was directly constructed on liquefiable foundation without reinforcement. Hence, it is essential to evaluate present antiliquefaction performance of this constructed embankment. The concept of performance-based design was introduced to the safety assessment. Dynamic centrifuge model tests are successfully applied to predict the seismic performances of the embankment. In order to reflect the real situation of the embankment, the materials and structures involved in the embankment were well replicated according to a scale rule. Moreover, the seismic wave used in model tests was determined according to the report of seismic safety of the site. Finally, the safety of antiliquefaction performance of the embankment was evaluated and discussed in light of the performance-based design concept.

This study focuses on the safety assessment of antiliquefaction performance of an embankment of a reservoir, which is an important infrastructure located in Shanghai, China. The performance-based design (PBD) philosophy is introduced for the assessment. In the accompanying paper, the experimental safety assessment using dynamic centrifuge model tests is presented. In this paper, an effective stress-based, fully coupled, hybrid, finite element–finite differences (FE-FD) numerical method is adopted for the numerical safety assessment. The numerical scheme is verified and validated using the dynamic centrifuge model tests reported in the accompanying paper and then applied to assess the safety of the whole embankment subjected to precautionary earthquake. The liquefiable soils are described by a well-calibrated cyclic elastoplastic constitutive model, while a Ramberg–Osgood model is adapted for the other soils. All the parameters used in the simulation are determined based on field data and element tests. The hydrodynamic pressure is also considered in the safety assessment. The seismic performances of the constructed embankment during and after an earthquake are predicted. The safety of antiliquefaction performance of the reservoir embankment is assessed based on the PBD concept.

Beaver Slide is near 177.8 km (110.5 mi) on the Dalton Highway and the road gradient is approximately 11%, built on a hill side. Each year, soft spots, also commonly named as frost boils, were observed starting from late April and lasting for the entire summer. The frost boils have resulted in an extremely unsafe driving condition and frequent accident occurrences. Conventional repair methods cannot effectively solve this issue. A newly developed geotextile, which has high specific surface area, was installed in the selected test section to mitigate the frost-boil issue in August 2010. This type of geotextile can provide high wettability and relatively high suction (capillary force), consequently be able to laterally transport water (a high-directional transmissivity) under unsaturated conditions. Test results over the initial 2 years had proved the effectiveness of the geotextile to alleviate frost heave and the subsequent thaw-weakening issue. However, there were still some concerns regarding its long-term performance, such as clogging of the microscopic drainage channels and mechanical failures. The data collected during the past 5 years were used to analyze and evaluate the effectiveness of the wicking fabric. A scanning electron microscope was used to explore the interaction between the wicking fabric and in situ soils, and to determine the condition of the fabric 5 years after the installation.

This study evaluated the impact of moisture-induced swelling pressure on a tieback wall constructed in high plasticity expansive soil. The study was based on laboratory soil characterization, field monitored seasonal fluctuation of moisture content, and numerical simulation. Soil samples were retrieved from a construction site at the intersection of I-35 and Walters Street in San Antonio, Texas, and two boreholes were installed to monitor the moisture profile at the site. Considering the field setting, a numerical model was developed to simulate the construction and performance of a tieback wall subjected to significant lateral earth pressure due to swelling. The model further assessed the impacts of different factors on the behavior of the tieback wall, such as moisture profile, surcharge, unbonded length of the soil anchor, and wall rigidity. The study indicated that more drastic changes in soil suction profiles between construction and in-service conditions may generate lateral stresses that result in excessive wall deflections. The swelling-induced lateral stresses of the expansive soil depended significantly on the permissible lateral displacement of the retaining wall. The greater surcharge and higher rigidity led to an increase in lateral stresses. In general, this paper suggests that no simple method can predict the lateral stress due to swelling of the expansive soil and a detailed finite-element method analysis is required for designing tieback walls in expansive soils.