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This briefing provides a short introduction to a supplement of the Ciria Manual on Scour at Bridges and Other Hydraulic Structures published in 2021. The supplement captures additional knowledge since the scour manual was published in 2015. This note is intended for designers and asset managers of structures in the water environment that may be subject to scour.

An experimental study was performed to investigate the effect of external prestressed truss steel-bar units installed on an unreinforced masonry (URM) wall under out-of-plane loadings. The key components of this new retrofitting method are prestressed vertical and diagonal bars. The prestressed vertical bars induce a prestressing force onto the horizontal section of the URM wall and the diagonal bars resist lateral loadings. Reverse cyclic tests were conducted on a full-scale URM wall as a control specimen and URM walls retrofitted in-plane and/or out-of-plane (parallel to short intersecting walls). The test results showed that the specimen strengthened using the new technique was superior to the control specimen in terms of seismic performance, including lateral load resistance, stiffness, energy dissipation and restrained slip of the entire specimen. Two units installed on short intersecting walls exhibited the same shear strength as four units installed on the in-plane and in-plane retrofitted masonry walls. The out-of-plane masonry specimen demonstrated the best performance. It was confirmed that aligning the retrofitting method based on the loading direction was effective, despite the lower axial load level.

This paper investigates the dynamic response and assesses the safety of a propylene tower subjected to blasting vibrations. A group of monitoring experiments on the response of the tower to blasting vibrations was carried out to this end. A model of a cantilever beam was used for the response along the horizontal direction and that of a strut for along the vertical direction. The theoretical and measured displacements were consistent in terms of time history curves and peak values. The design spectrum of the tower suitable for sustaining blasting vibrations was then proposed and verified, and its safety was assessed in combination with local requirements on seismic design. The results show that the first six modes of response should be considered under blasting vibrations in the horizontal direction, instead of the first three modes as in the case of an earthquake. The first three modes should be considered under blasting vibrations in the vertical direction. Owing to the importance higher modes in this scenario, the shear should be taken as the primary object of evaluation when assessing the safety of a tall propylene tower subjected to blasting vibrations.

It has recently been shown that the ever-increasing complexity and inability of methods used for the design of reinforced concrete (RC) structures to consistently safeguard against brittle types of failure is the outcome of the conflict between the assumptions of the underlying theory and the fundamental concrete material characteristics. This paper demonstrates that these drawbacks can be eliminated through a coherent alternative theory developed on the basis of simplified beam theory modified to account for true concrete behaviour. Through the use of experimental information obtained from the literature, the proposed theory shows that, in contrast with widely held views, a structural member's load-carrying capacity depends solely on the strength of the compressive zone, which was found to be significantly larger than what it is widely considered to be. Moreover, load transfer is accomplished by the bending action of the concrete cantilevers formed between consecutive inclined or flexural cracks in the tensile zone. The above findings essentially underline the development of an alternative design method – the compressive force path method – and this is an indication of the suitability of the proposed theory to open up new possibilities for improving RC design.

Past bridge failures due to earthquakes have been found to be due to inadequate seismic design of the bridge piers. It is thus essential to investigate the effect of lateral confinement on the seismic behaviour of bridge piers. The aim of this study was to evaluate, experimentally and numerically, the seismic performance of reinforced concrete bridge piers with various types of transverse reinforcement. For this purpose, three scaled-down (1 : 4) circular bridge pier specimens were tested under constant axial and quasi-static cyclic loading (QSCL). A control specimen was made with spiral lateral reinforcement, while the other two specimens were made with stirrups with cross-ties and strips with cross-ties. The hysteresis loops, envelope curves, energy dissipation and stiffness degradation of all three specimens were determined in order to evaluate their seismic behaviour. Compared with the control specimen, the specimen with strips and cross-ties showed increased lateral load capacity, cumulative energy dissipation and higher initial stiffness due to the effect of increased confinement. The results of finite-element analysis showed good agreement with the experimental results. The findings of this study indicate that strips with cross-ties can be used in bridge piers when a high lateral load carrying capacity and energy dissipation are required.

The ‘rope effect’ is a positive effect caused by the failure of fasteners of dowel-type connections. A similar mechanism can be found in connections with screw reinforcement. For self-tapping screws used as reinforcement for connections, bending of the self-tapping screws tends to close developed cracks. Utilising the withdrawal resistance provided by the threads on the pointed end of the screw and the pull-through resistance from the screw head, screw reinforcement enhances the embedment strength and splitting resistance of the wood and increases the ductility of the connection. The influence of different thread lengths and locations on reinforcement effectiveness regarding the embedment strength of the timber was investigated in this study. For cases with threads located only on the pointed end, the splitting resistance increased with longer thread length, indicating that the rope effect was progressively enhanced. It was also found that screws with halved thread length demonstrated similar reinforcement effectiveness to fully threaded screws while the partial threads reduced the risk of damaging the screw during installation. A calculation method to predict the load-carrying capacity of screw-reinforced dowel-type connections was also formulated.

The application of dynamic compaction (DC) on former (backfilled) opencast coal mining sites has increased over recent years in the UK, to reduce or mitigate the impact of inundation collapse compression of uncompacted, overburden backfill, as part of the site re-development package. Some of these aspects are discussed in this article, including the importance of close observation of ground response to DC, at each stage of its execution, to ensure its satisfactory implementation and the implications of limitations on the maximum size of DC weight (tamper).

Modal analysis of concrete arch dam–reservoir–foundation rock systems is a challenging task. The complexities arise mainly due to computing mode shapes encountered when solving an eigenvalue problem with asymmetric generalized mass and stiffness matrices. Moreover, the problem becomes complicated when wave propagation is occurring due to the inclusion of water compressibility and foundation rock mass. In the present study, a computational tool is especially developed for this purpose. The theoretical background is explained initially. Subsequently, dynamic analysis of the Morrow Point arch dam–reservoir–foundation rock system is carried out with different values of reservoir bottom absorption coefficient. In addition, some of the modal characteristics of such systems, including resonant frequencies and natural periods, are discussed. The main objective is to perform these analyses by modal analysis. However, the direct method of analysis is also carried out in each case as a basis for comparison from the perspectives of accuracy and efficiency.

Stress concentrations in a new type of reduced-beam-section (RBS) connection were investigated. Experimental and numerical results of RBS connections with semilunar web (SW) and holed tubular webs (HTW) were compared with connections with tubular webs (TW). For the SW, two semi-circular plates were used in place of a flat web in the beam. For the HTW, a steel tube was used instead of part of the beam web and holes were created in the beam web. For the TW, a steel tube was used instead of part of the beam web but without holes. The connections had adequate shear capacity but made little contribution to flexural stiffness and capacity. Semi-deep beam specimens were fabricated and tested under cyclic loading. The results showed that the beam connections with SWs and HTWs had 30% and 20% less fatigue damage respectively than those with TWs. The story drift capacity was also increased to 7%, much more than that stipulated by current seismic codes. The specimens were modelled using finite-element software to validate the experimental results.

This paper presents the results of both experimental and numerical investigations on the overall structural performance of two-equal-span reinforced concrete perforated (castellated) beams subjected to external pre-stressing. First, the effects of providing castellated openings along with the application of external pre-stressing on both the ultimate capacity and the percentage of moment redistribution were investigated experimentally. Then, after validation of the numerical modelling, the effects of controlling the parameters on the percentage of moment redistribution were investigated numerically. Experimental results showed that providing castellated openings accelerated the appearance of both flexural and shear cracks, and decreased the ultimate capacity by about 24% compared to that of a solid beam. Moreover, application of external pre-stressing on the castellated beam compensated for the reduction in ultimate capacity and outperformed it by about 9% compared to that of a solid beam. Based on the numerical results, it appears to be better to increase the amount of main tensile steel and strand eccentricity at the hogging moment zone, as well as increase the effective pre-stressing force, to reduce the percentage of moment redistribution at both sagging and hogging moments.

The aim of this study was to develop an efficient probability-based seismic fragility assessment method for steel moment-resisting frames (MRFs). In this method, Bayes estimators are used to improve the accuracy of the results based on new analyses or experimental observations. The efficiency of Bayes estimators in the updating process of fragility curves is demonstrated based on the results of incremental dynamic analysis of three-, five- and seven-storey steel MRFs under a set of 40 spectrum-compatible earthquake ground motions. The results indicate that the constant-hazard-level (engineering demand parameter based) fragility analysis approach leads to less than 6% error in the prediction of performance levels and therefore can be considered a competent alternative to the more computationally expensive constant-performance (intensity measure based) approach. While the earthquake duration can considerably affect the results of fragility analysis, the prediction errors can be reduced to an acceptable level through selection of four different time intervals with at least three records in each group. It is also concluded that Bayes estimators can generally provide a very good level of accuracy in updating fragility curves by reducing the maximum errors to less than 2.5% compared with the exact values.

Radiative cooling without energy consumption and environmental pollution holds great promise as the next-generation cooling technology. To date, daytime radiative cooling performance is still slightly low, especially in humid areas. In this work, we demonstrated that nanoporous polyethylene (Nano PE) film can improve solar reflectivity from 96% to 99%, thus boosting radiative cooling performance. Moreover, the experimental results in humid areas indicate that Nano PE films can improve radiative cooling performance by ∼76% in a clear day and 120% in a day with few clouds. Additionally, compared with ordinary PE films, thin Nano PE films have significantly higher weather fastness and mechanical strength. More importantly, nano PE films can scatter part of visible light, thus suppressing the generation of light pollution in practical applications. Lastly, the modeling results reveal that with Nano PE films, more than 95% of China's areas can achieve daytime cooling performance. Our work can boost the development of radiative cooling technology with a very low cost.

The architecture, engineering, and construction (AEC) industry is undergoing a substantial change, and the technological advancements are shaping the future of this industry. Over years, numerous tools have been developed based on building information modeling (BIM) and the Internet of Things (IoT) to manage a variety of tasks and activities within different construction and operational phases in the AEC industry. Recently, with the advent of novel internet-enabled technologies in providing the ability of real-time connectivity, researchers have started to develop virtual design and construction (VDC) and digital twin approaches to remotely monitor, control, and optimize different work progresses and activities in real-time at any work level in the AEC industry. This paper presents a reference model to illustrates the main advantages and applications of VDC and digital twin, and to demonstrate their trends and anticipated cost savings in the AEC industry at a global level. These technological advancements along with augmented reality (AR) and virtual reality (VR) can offer the unique benefit of real-time monitoring of the current status as well as predicting the future of any physical structure at any level of work. The global demand and usage of these technological advancements will lead to great cost savings in the AEC industry which would be US$950 million in design and construction and US$400 million in operation and maintenance phases in the non-residential AEC industry in 2025. This paper also discusses the future challenges of VDC and digital twin in the industry. As a main line of future research, these technologies can simultaneously be utilized with artificial intelligence to enable human-centered decision making to automate and optimize work progresses. Such integrations of VDC, digital twin, artificial intelligence, and human-centered approaches will shape the future of the AEC industry and provide numerous research opportunities in this domain.

Geothermal energy with abundance and large quantity can partially cover building heating/cooling loads and promote the carbon-neutrality transitions. Shallow geothermal ventilation (SGV) system, with a little initial investment cost, is one of promising technologies to partly replace the conventional air-conditioning system for air pre-cooling/pre-heating. This paper reviews applications of SGV system for improving thermal performance over latest two decades, which mainly includes the reclassification of SGV system, coupling with other advanced energy-saving technologies, application potentials for building cooling/heating under various weather conditions. Heat transfer mechanism and mathematical modelling techniques have been reviewed, together with in-depth analysis on current research trends, existing limitations, and recommendations of SGV system. Phase change materials, with considerable latent energy density, can stabilize the thermal performance with high reliability. The review identifies that optimization designs and advanced approaches need to be investigated to address the existing urgent issues of SGV system (e.g., large land occupation, difficulty in centralized collection of condensate water timely for horizontal buried pipe, bacteria growth, polluted supply air, and high construction cost for vertical buried pipe). A plenty of studies show that the SGV system could greatly expand the application scope and improve system energy efficiency by combining with other energy-saving technologies. This paper will provide some guidelines for the scientific researchers and engineers to keep track on recent advancements and research trends of SGV system for the building thermal performance enhancement and pave path for future research works.

A finite-element (FE) investigation into the response of integral abutment bridges (IABs) to seismic loading in the longitudinal direction was conducted. An example multi-span reinforced concrete solid-slab bridge was designed and analysed using an elasto-plastic two-dimensional FE model. The bridge abutment was taken as supported on steel H-piles. The proposed FE model was found to have the capability of simulating both the bridge construction and the backfilling process using a multi-step numerical process. The bridge was examined considering various lengths and different backfill materials, and was subjected to earthquake loading. The analyses showed that the seismic response of IABs is notably affected by the bridge length. Longer bridges may be subject to higher pressures on the abutments and internal forces in the bridge structure. The stiffness and strength parameters of the backfill material may also markedly influence dynamic pressures on the abutments and internal forces in the structure. Backfill materials with greater stiffness and strength parameters may cause significant reductions in the seismic flexural stresses in both the abutments and the deck. Coupling seismic and thermal loads could be suggested for the design of IABs.

The performance of integral bridges subjected to a multi-component earthquake has not been thoroughly investigated. Here, the responses of an integral bridge subjected to three-component far- and near-field earthquakes are determined to evaluate its relative structural advantages and disadvantages over a conventional bridge. Further, the effect of the interaction between the internal forces in the three directions on the total responses or yielding due to simultaneous application of the three components of an earthquake is investigated. For this purpose, two geometrically comparable bridges, one integral and other conventional, are analysed under far- and near-field earthquakes using SAP2000. The parameters varied are the type of ground motion, peak ground acceleration and orientation of the major horizontal component of the ground motion. Seismic demand parameters include the maximum bending moment in the girders, maximum moments at the top and bottom of piers, displacements in three directions and the plastic hinges formed. The results of the analysis show that the deck of the integral bridge has smaller displacements when compared with the conventional bridge. A greater number of plastic hinges are formed in the integral bridge, but the degree of damage shown by the hinge rotations in the conventional bridge is greater.

The effects of high-strength steel (HSS) on the damage indices (DIs) of four special moment frames and three beam–column connection (BCC) specimens under cyclical loading were experimentally studied. The specimens with HSS rebars (with yield strengths of 500 MPa and 580 MPa) were designed and constructed based on the special seismic provisions of ACI 318-19. Several types of DIs (from single DIs to combined DIs based on parameters such as displacement, absorbed energy and stiffness) were calculated according to the experimental results. The results showed that the application of the higher strength steel expedited the failure process of the specimens. Moreover, the DIs indicated that the specimen fitted with HSS for both the longitudinal and transverse rebars had the greatest damage propagation speed of the frames. For the BCCs, the specimen with HSS as just the longitudinal rebars showed the greatest damage propagation speed. The results also showed that the displacement-based DIs were less accurate than the other types of DIs for studying the damage behaviour of both the frame and the BCC specimens. The combined DIs were found to be more accurate than the other DIs.

The Wan Jiang Bridge in China was damaged by ship impact and subsequently restored. This paper presents a detailed evaluation of the residual service life (RSL) of the bridge using the reliability analysis method of the Joint Committee on Structural Safety, based on the structural load-bearing capacity (LBC) of the bridge and the design load. Data were collected from bridge design codes, field loading tests and finite-element (FE) analysis. The LBC was initially calculated and subsequently revised using specific coefficients. Using FE analysis, the bending moment on the control section of the bridge was determined under the most unfavourable loading conditions and the ultimate LBC of the bridge was checked. Subsequently, static and dynamic loading tests on the restored bridge were conducted, with the load and capacity determined for the control section based on FE analysis. The loads considered were dead load, vehicle load and crowd load. A time-dependent reliability index was developed for the restored bridge using the probability distributions of capacity and design load variables, and the RSL was determined. This case study, predicting the RSL of the bridge based on a multitude of data, should be valuable for future bridge maintenance and management.

In recent years, the aging of existing reinforced concrete deck slabs of road bridges in Japan has been attributed to the deterioration of the concrete on the upper surface, and partial replacements have been carried out as a measure to extend service life. This study comparatively verifies the effectiveness of the partial cross-section replacement method, using a wheel load running test and focusing on the combination of the removal method of the existing concrete and the repair material. An appropriate method of partial replacement of existing reinforced concrete deck slabs is also proposed.

An investigation was carried out to improve the seismic performance of concrete columns reinforced with high-strength steel bars and subsequently retrofitted with vertical and horizontal carbon-fibre-reinforced polymer (CFRP) strips. Seven columns were constructed and tested under constant axial and cyclic lateral loading. The results showed that attaching CFRP vertical strips in or over grooves outperformed conventional externally bonded reinforcement, as evidenced by greater energy dissipation and strength. Furthermore, the use of corner strip–battens for the horizontal CFRP strips was found to outperform conventional wrapping, as evidenced by greater ductility and energy dissipation. Confining stresses were also more uniformly distributed and strip rupture shifted from the edges to the mid-sides of the section.

This paper contains a summary of the experience obtained by researchers at the Instituto Universitario de Ciencia y Tecnología del Hormigón (ICITECH) at Universitat Politècnica de València (Spain), in the last 30 years of investigating reinforced concrete building structures under construction. During this period, ambitious experimental campaigns and advanced computational simulations have been carried out, and new analytical methods have been formulated to assess slab–falsework load transmissions in buildings under construction. From all these campaigns the following main conclusions can be derived. First, it is important to consider construction processes when planning building projects. Second, the use of analytical methods to evaluate construction processes need to be adapted to the current requirements of efficiency and sustainability. Third, there is a need to improve the robustness of temporary shoring or propping structures. Improving the construction sector necessarily involves the implementation of the above measures in buildings under construction and the use of new monitoring and inspection technologies for the construction processes applied.

The radiant systems consume less energy and provide better thermal comfort as compared to the conventional system, but the main drawback of radiant technology is inability to cater the latent load and condensation. This problem has engaged researchers to push their emphasis on Personalized Conditioning System (PCS). It forms a micro-climate region near the occupant. This study is aimed at PCS combined with a radiant conditioning system, which evaluates the performance of the PCS and compares it with different radiant cooling systems. A radiant cubicle was used to investigate the performance of the PCS for both heating & cooling modes. For heating mode, the Standard Effective Temperature (SET) was calculated with the help of thermal comfort surveys which were in a range of 23.4°C to 27.3°C. For cooling mode, four different cases compared the performance of the system which are: Conventional Air Conditioning System (CACS), Radiant Cooled Ceiling System (RCCS), Personalized Radiant Conditioning System (PRCS), and both PRCS-RCCS coupled. It was observed that PRCS alone reaches the thermal comfort criteria with low energy consumption. The energy-saving of RCCS-PRCS was achieved 38% when compared with CACS. It can be concluded that PRCS is a new step in the field of thermal comfort.

This paper reports on a numerical study into the crack-dependent behaviour of a steel-plate girder bridge strengthened with carbon-fibre-reinforced polymer sheets. Progressive cracking, which represented fatigue-induced damage, was simulated from up to 10% of the girder depth. Finite-element analysis was used to evaluate the performance of the control, damaged and strengthened cases subject to standard US highway fatigue loading. The efficacy of polymer strengthening was also examined from a strength perspective, using the load factor rating method and the load and resistance factor rating method. Localised fatigue cracking caused a stress concentration along the girder and its progression rate was related to the degree of web fracture. The damage of the tensile flange was more influential in reducing the flexural capacity of the girder relative to damage of the web. The strengthening decreased the stress ranges, thereby increasing the fatigue life of the girder, and enhanced the maximum average daily traffic capacity. Reliability modelling indicated a transition in failure rates before and after 3% cracking in the girder, supporting the extended functional time resulting from strengthening.

To resolve the problem of ductile fracturing of beam flanges in traditional connections with concrete-filled steel tube columns using site-welded side plates, an alternative connection design requiring minimal site welding was designed and studied. An explicit analysis method, considering the fracture strain criterion developed by the stress triaxiality path, was adopted to study the seismic performance and fracture resistance of the proposed connection. The results of a verified finite-element model indicated that the steel beam flange in the connection never fractured. The connection exhibited a notably higher maximum bending moment and ductility than the traditional connection. The side plates in the proposed connection were tension-bending or compression-bending elements, unlike in the traditional connection. The failure modes, maximum bending moment, ductility and stress distribution of the side plates were compared and analysed parametrically. Based on the stress distribution of the side plates according to the finite-element results, a fitting formula related to the width and thickness of the side plates was obtained. A formula to calculate the flexural capacity was also developed according to the force model of the proposed connection. The calculations and finite-element results were in good agreement.

Enhancing the energy efficiency of structures has been a staple of energy policies. The key goal is to slash electricity usage in order to minimize the footprint of houses. This goal is sought by putting restrictions on the design specifications with respect to the properties of the raw materials and components as well as the exploitation of sustainable sources of energy. These facts for the basis for zero-energy building (ZEB) being established. This novel technology has faced several obstacles impeding its commercialization and future advancement. This investigation therefore holistically explored and evaluated the state of zero energy building and factors impeding their commercialization. The review further proposed some suggestion in terms of technology that can be considered by the sector to augment existing technologies. Similarly, the investigation touched on the effect of occupant's character in zero energy structures. Policies in terms of government subsidies and tax rebates were recommended to encourage more investors into the sector. Finally, the perception of zero energy building being more expensive compared to the traditional structures can equally be curbed via efficient and effective public sensitization.

The distribution of earthquake-induced energy in a 42-storey reinforced concrete dual-system building at three ground shaking intensities was investigated. The earthquake-induced energy response of the building was obtained in terms of elastic energy (kinetic energy and strain energy) and inelastic energy (hysteretic energy and structural damping energy) components for each structural member. Hysteretic energy is an indicator of inelastic deformations (i.e. potential damage) and is considered particularly important as it leads to high irrecoverable energy demands in a building and identifies critical members that require higher energy absorption capacity. The ratio of hysteretic energy to input energy was assessed among different structural members as well as along the building height. The results showed that the hysteretic energy constituted less than 10% of the total input energy and was mostly dissipated in the frame members for low-intensity events, whereas 75% of the input energy was dissipated in the hysteretic mechanism, prominently by the beams. In terms of hysteretic energy demands, the critical floor levels were found to be the 12th and 26th floors. The findings of this research will help engineers obtain a reasonable estimate of the expected hysteretic energy demand once the input energy is known.

This paper systematically describes the technical principles, evaluation indicators, system forms and research progress of air-side evaporative cooling air conditioning systems, water-side evaporative cooling air conditioning systems and freon-side evaporative cold coagulation heat air conditioning systems of Data center. In order to reduce the energy consumption of the refrigeration and air-conditioning system in the Data center, the application conditions and scenarios of the different forms of evaporative cooling air-conditioning systems should be considered comprehensively. Therefore, it is very important that the renewable energy-dry air can be used to the greatest extent. These efforts would contribute to China's 2030 "Carbon Peak" and 2060 "Carbon Neutral."

The photovoltaic-thermal collector is one of the most interesting technology for solar energy conversion, combining electric and thermal energy production in a single device. Vapour-compression heat pump is already considered the most suitable clean technology for buildings thermal energy needs. The combination of these two technologies in an integrated ”photovoltaic-thermal solar-assisted heat pump” (PVT-SAHP) system allows reaching a high fraction of the building thermal needs covered by renewable energy sources and to improve the performances of both the photovoltaic-thermal collector and the heat pump. The first is cooled down increasing its energy conversion efficiency, while providing low-temperature thermal energy to the second, which benefits from a higher evaporation temperature. The review study presents the state-of-art of photovoltaic-thermal solar-assisted heat pump systems intended to cover thermal energy needs in buildings, with a particular focus on the integration methodologies, the possible configurations, the use of different sources and the design of sub-system components. These issues are addressed by much scientific research, to improve the reliability and applicability of this technology, as an option for the building decarbonization. This study aims to present PVT-SAHP systems in an organic and critical way to propose a useful tool for future research developments. More in detail, the work highlights the fact that the integration of photovoltaic-thermal collectors as evaporator of the heat pump in direct-expansion systems allows the highest heat recovery and performances. However, the distinction of the two circuits lead to more reliable, flexible and robust systems, especially when combined with a second heat source, being able to cover both heating and cooling needs. The implementation of real-time control strategy, as well as the continuous development of the compressor and refrigerant industries is positively influencing this technology, which is receiving more and more attention from scientific research as a suitable solution for nearly zero energy buildings.

This paper deals with the experimental investigation of hygrothermal behavior of wooden-frame building envelope. The experiment was based on in-situ monitoring of a full size experimental monozone house built at the University of Lorraine. Variations in temperature and relative humidity inside and outside the envelope were logged simultaneously with local meteorological data. Results showed the high coupling between temperature and relative humidity variations within the envelope materials. An overall hygrothermal response of the wall highlighted an interesting hygrothermal dynamic behavior of the envelope which may contribute to mitigate variations of relative humidity inside the building. Nevertheless, relative humidity evolves within a range of values ​​that can lead to mold growth at a certain position which may alter wooden envelope life.

The construction industry is the most significant occupational contributor to suicide rates worldwide. This is credited to strenuous working conditions, lack of awareness in mental health culture, but more so, that help-seeking is seen as a weakness. This study aims to investigate the role of the construction project manager in creating a culture of suicide prevention on-site. This is achieved through delving into the principles of culture creation within differing industries, with adaptations for construction managers, through a comparative analysis of culture creation literature. Twenty-two interviews with employees are undertaken. Representative data gathered are analysed and presented, to highlight the levels of knowledge, barriers and proposed solutions, for construction project managers. Results are broken down into ‘awareness of and openness to discussing suicide prevention’, ‘barriers to the adoption of suicide-prevention measures’ and ‘proposed solutions to the adoption of suicide-prevention measures’. The interviews give an insight into the acceptance of the need for stronger mental health support structures, without necessarily any regard for the method of their implementation. The originality and subsequent value in the research are the proposed use of construction project managers as the conduit in beginning to address and, as a result, develop a culture of suicide prevention on-site.

Thin-walled shell structures are characterised by a lightweight structural form with high strength. The importance of using cylinders and cones has long been known to engineers and designers in various engineering disciplines and they are widely used in shell form. In this work, the buckling and post-buckling behaviour of thin-walled cylindrical shells with geometric imperfections was investigated under vacuum-type pressure loads. Ten shell models with dents of two depths and lengths were designed for experimental tests: the dents were the thickness or twice the thickness of the shell, while their lengths were half or one-third of the height of the model. Carbon-fibre-reinforced polymer (CFRP) was used to retrofit some of the dented models. Test results from the CFRP specimens and the non-CFRP specimens were then compared with each other and with theoretical calculations.

The aim of the present paper is to compare the current design codes’ predictions for reinforced concrete (RC) T-beams with the alternative physical methods – namely, the compressive force path (CFP) method and artificial neural networks (ANNs). Therefore, two databases, for T-beams without stirrups and with stirrups, are developed using the available experimental studies. The comparative study on prediction (obtained from the American Concrete Institute and Eurocode 2, CFP and ANN models) shows that the predictions of the ANN model provide a closer fit to the experimental results; after ANN the predictions of the CFP method are close to the experimental results when compared with the counterpart physical model. Comparative studies are also conducted on the critical parameters for the behaviour of RC T-beams. Furthermore, a non-linear finite-element tool (i.e. Abaqus) is used to validate the prediction of the ANN and CFP model. The crack pattern from Abaqus exhibited the same mechanics, on which the CFP models are based.

To understand the influence of the layout and geometric parameters of the lining concrete on the mechanical properties of multi-cell single-box girder bridges with corrugated steel webs, the Fenghua River Bridge is taken as an example. This is a single-box three-cell continuous girder bridge with corrugated steel webs that is the largest of its kind in China. It was used to establish the finite-element model in this paper. The results of this study suggest that the lining concrete single-side arrangement has good economic and mechanical properties. The influence of the geometric parameters of the lining concrete on the mechanical properties of the structure was studied using the finite-element model, and the length and thickness range of the lining concrete of the single-box multi-cell composite girder bridge with corrugated steel webs are provided. The research results provide useful suggestions for the design of lining concrete in real bridge projects, and thereby make up the gap in the existing code.

Self-tapping screws have the potential to reinforce timber elements. However, their application is restricted due to a lack of design guidance. Compared with fully threaded screws, partially threaded screws with a shorter thread length have less drive-in torque, enabling easier installation. This study showed that partially threaded screws are as effective as fully threaded screws in enhancing the mechanical properties of single-dowel timber connections with artificial cracks. A total of 120 embedment tests were conducted, using screws with two thread lengths (33% and 100%) on single-dowel connections. The connections were also prepared with three different widths of artificial crack to represent splitting of the wood due to moisture variation. The results showed that the screws with 33% thread length were as effective as screws with 100% thread length at reinforcing the connections when the crack width was 1.5 mm or 4.5 mm. However, for a crack width of 6 mm, the embedment strength of the connections reinforced with screws with a 33% thread length was significantly lower (about 15.7%) than the connections reinforced with screws with a 100% thread length. This research demonstrates the potential of using self-tapping screws with a partial thread to reinforce existing timber elements with cracks.

Shortages in materials, skilled labour and equipment are well known within construction industries, and impede performance on ongoing and pipeline projects. This study explores international construction joint ventures (ICJVs) as a resourcing model that could relieve pressures within the New Zealand (NZ) construction industry. The study goes further to identify the risks and constraints associated with ICJVs. There is a dearth of literature on the role of ICJVs and their impact on the industry within the context of resource acquisition. The data for this study were collected by way of the administration of an online questionnaire survey to a representative sample of contractors, developers and consultants. A simple descriptive method of analysis was employed for ease of understanding. The study established that materials and labour were the most demanding resources that ICJVs could help address in NZ. Risks associated with compliance with local regulations and certification requirements and those related to lead times were the most critical constraints for international material acquisition. The study findings also indicate that language and communication barriers and differences in the practice of rules and regulations were the most significant constraints for utilising international skilled labour.

Modular projects can be of higher quality, a safer, faster and more predictable construction process, and less environmental nuisance compared to a traditional on-site project. High-rise projects seem to be particularly suitable for modular building methods, however there are still some process-related barriers. Research so far has not focused on collaboration forms for modular high-rise projects. This paper examines which collaboration form fits best for a modular high-rise project by conducting an international case study research. From the case studies it is debatable whether the current PDMs meet the need for modular concepts; modular buildings will benefit more from a long-term collaboration with fixed partnerships. This requires a complete different approach to the construction industry. Until then, the best match should be sought by matching the customer profile to the PDM characteristics. The most suitable PDM is dependent on the client profile that can be determined by 17 selection criteria.

In order to promote the application and development of steel–concrete composite beams in bridges, the fatigue performance of corroded studs was investigated. Based on fatigue crack propagation theory and the fatigue failure mechanism of corroded studs, a fatigue life prediction model for corroded studs was proposed. The values of key parameters in the fatigue life prediction model of corroded studs were obtained. Moreover, the fatigue life of corroded studs was analysed. Results show that the error between the calculated value and the test value of the fatigue life of corroded studs is less than 10%, and the fatigue life prediction model for corroded studs is sufficiently accurate. As the corrosion rate of a stud increases, its fatigue life rapidly decreases. When the corrosion rate of the stud increases from 5 to 50%, the fatigue life of the stud decreases from 20 to 90%, respectively; thus corrosion greatly reduces the fatigue life of the stud.

Different methodologies have been suggested in the literature to simulate the adverse impact of reinforcement corrosion on the non-linear structural behaviour of deteriorated reinforced concrete (RC) structures. The modelling methodology used, however, can significantly bias the predicted time-dependent structural behaviour of deteriorated structures. Considering the critical importance of numerical modelling in bridge maintenance scheduling and effective decision making, the influence of different modelling strategies on the anticipated time-variant structural performance of corroded concrete bridge columns is investigated. To this end, various simple and advanced modelling methodologies are evaluated. The effect of the considered modelling scenarios on the estimation of damage limit states, the sequence of multiple failure modes, structural capacity (both ductility and strength) and energy dissipation capacity of a benchmark circular RC column is evaluated over its service life. The results show that the modelling strategy significantly affects the predicted time-variant structural performance of the deteriorated structure.

In mechanised tunnelling, the filling of the annular gap behind the precast concrete segments is one of the essential operations. The main goal of filling this space is to reduce surface settlements and limit movements due to tunnel excavation in the soil mass. To achieve this aim, a two-component grout is often used to fill the annular gap. Determination of the amounts of ingredients in the two-component grout should be carried out in such a way that the injection materials will be able to fulfil the required performance and technical properties. In this study, laboratory tests were carried out to investigate two-component grout properties, such as flowability, bleeding, gelling time and uniaxial compressive strength. The effect of lateral pressure on grout resistance was studied according to real excavation situations. The influences of the grout ingredients and effective parameters such as bentonite and cement contents, water–cement ratio and the dosage of accelerator (sodium silicate) and accelerator ratio were also investigated.

Water is much more than the molecular common thread to life on Earth. The supply, storage, protection and use of water are expansive topics that universally engage every layer of the world’s social, economic and political spectrum. The built heritage associated with water is steeped in civil engineering achievements meeting critical social needs, examples of which can be found around the globe, from the karez irrigation systems of China’s Xinjiang Region to the aqueducts of ancient Rome, to the step wells of India and the Incan canals of Peru. Infrastructural heritage built to deliver reliable, safe and abundant supplies of water to homes and public baths, agricultural fields and distributing reservoirs continues to function in urban and rural communities across the globe. This paper focuses on some of the unique challenges associated with the stewardship of this water infrastructural heritage, at the intersection of water management and historic preservation.

Cold-formed steel members are usually used as purlins in buildings to support roof cladding and thus they can be treated as beams restrained fully or partially in the lateral and torsional directions. However, when these beams are subjected to wind suction loading, their free flange is in compression, which may cause web–flange distortional buckling (WFDB). This paper presents an analytical study on the WFDB of zed-section purlins when subjected to uplift bending. A simplified model is proposed to describe the WFDB of partially restrained purlins, from which the formula for calculating the critical stress of the WFDB is derived. The present model is validated by the results obtained from the finite strip analysis.

Reliable column–column connection contributes to a reduction in waste materials and enables structures to be demountable after their service life. This paper demonstrates the feasibility of using a bolted-flange connection with concrete-filled steel tube (CFST) columns subjected to axial compression load. Compression capacity, ductility, axial stiffness and toughness, as well as failure modes are discussed. The specimens are grouped into two categories: group I—connection without stiffeners and group II—connections supported by stiffeners. Three thicknesses of 2, 4 and 6 mm were used to manufacture the bolted flanges and stiffeners. The results showed that the proposed connection was effective to avoid a reduction in compression capacity. The various thicknesses of bolted flanges in group I specimens had a slight influence on the axial stiffness value and that influence was doubled in group II specimens. The stiffeners played a significant role in the toughness value and this was reduced with a reduction in the thickness of the stiffeners. In addition, an improvement in ductility was noticeable in stiffened specimens. Consequently, it can be inferred that bolted-flange joints have the potential to produce reliable and economical designs for CFST columns.

Having made a globalisation decision, a contracting firm subsequently needs to make market selection decisions that are influenced by the level of uncertainty or the risks involved, the probability of winning the bid and the expected profitability, or based on generally expected utility. This paper aims to develop a globalisation entry decision-supporting tool integrating resource-based view (RBV), dynamic capabilities and Porter’s generic value chain for international project selection. Through the combination of a questionnaire survey and an interview survey analysed by partial least squares structural equation modelling, a globalisation entry decision-supporting tool for facilitating project selection decision for contractors venturing internationally was developed. This study attempts the usage of an anomaly-seeking method in combining theories from three streams of strategic management concepts – namely, RBV, dynamic capabilities and Porter’s generic value chain theories – into an integrated decision-supporting tool for risk forecasting and project selection in the international construction market. This study contributes to the knowledge of risk assessment by enhancing the current international entry decision tools with a firm’s capability component. The model developed enables a firm to be informed of the combination of the firm’s capabilities needed to lower the exposure to certain risks.

Early contractor involvement involves engaging contractors to work with the client’s design team during the pre-construction stage before agreeing on a construction stage contract. Despite the growing use of two-stage contracting, there is a lack of research into the forms of pre-construction service agreements and their effectiveness. This study aims to evaluate the optimal contract ingredients for a pre-construction stage agreement that can be used with a range of standard-form construction contracts based on industry preferences. Four agreements are critically evaluated: those of the Joint Contracts Tribunal and NEC3 and two bespoke agreements. Key ingredients were found to include scope of services, time obligations, design obligations, key personnel, price formation, confidentiality of material and communication and co-operation. Industry preferences were obtained through semi-structured interviews with 21 construction participants across New Zealand.

Generally, in reinforced concrete (RC) core wall buildings, the formation of one plastic hinge at the base is preferred; this is called the single plastic hinge (SPH) approach. During a severe earthquake, this approach results in significant moment demand in the upper regions of the wall due to the effect of higher modes of vibration. This study considered RC core walls of 30-, 40- and 50-storey buildings, designed using a response spectrum analysis. The SPH, dual plastic hinge (DPH), triple plastic hinge (TPH) and extended plastic hinge (EPH) approaches were examined using fibre element models and non-linear time history analysis. The DPH and TPH approaches respectively contain one and two plastic hinges at the upper levels of the wall in addition to the base plastic hinge. The effect of the locations of the upper plastic hinges on the seismic response of the core wall was investigated. The results showed that there is not a distinct level for the upper plastic hinge location to minimise the envelope of different demand quantities simultaneously. The curvature demand of the middle plastic hinge in the TPH case was higher than the base curvature demands. Reducing the resistant moment at the wall base by reducing the reinforcement ratio can help to balance curvature demands along the height of the TPH model.

Vibration properties of civil structures, which are commonly analysed for damage detection, are affected by changing environmental and operational conditions, and most notably are subjected to bilinear effects from changing ambient temperature conditions. Therefore, damage detection in structures during the past decade has focused on eliminating the effects of these changing environments that affect the vibration properties of the structures. Several methods have been proposed in the literature to tackle the non-linear effects from changing environments. However, these methods can only analyse systems (e.g. natural frequency–environmental and operational system) that have an incremental change in relationship; they cannot model the bilinear effects from the changing temperature conditions, which may lead to false alerts. Hence, a damage detection method is proposed in this paper to tackle the piecewise effects from changing temperature conditions. The method makes use of a Gaussian mixture model to separate the different effects acting on the structures and uses principal component analysis for data processing. The method is applied to the Z24 Bridge, in Switzerland, which was subjected to bilinear effects from changing temperature conditions. The results obtained demonstrate that the proposed method successfully takes into account the piecewise effects to indicate the presence of damage.

Bridges are essential components of transportation systems and their unacceptable performance following a disaster may lead to disruption to relief operations. Many existing bridges all around the world were designed based on early editions of seismic codes and the performance of some old bridges following seismic events has revealed that they are seismically vulnerable. This paper provides a comparison of the seismic performance of reinforced concrete (RC) bridges designed according to recent code editions and according to earlier provisions. To this end, a probabilistic seismic safety assessment of RC bridges was conducted. Non-linear response history analyses were performed for each set of bridge samples subjected to earthquake ground motions with different severities employing three-dimensional models. The effect of the earthquake focal mechanism on the seismic vulnerability of the bridges was investigated. Moreover, fragility curves were developed for RC bridges designed according to the latest edition of the American Association of State Highway and Transportation Officials (Aashto) specifications (so-called new bridges) and those designed based on pre-1980 specifications (so-called old bridges). The fragility curves are presented in terms of the geometrical specifications of the bridges and the focal mechanism associated with input motions for both new and old bridges.

Distributed electricity generation technologies, like solar photovoltaic (PV), have achieved rapid development in recent years, but are constrained by some problems such as low marketization and lag in public services. The peer-to-peer (P2P) electricity trading, which allows direct electricity transactions between local consumers and prosumers, has the potential to efficiently distribute the profits coming from self-consumption of PV electricity among all participants. This study proposes a three-layer P2P electricity trading system for communities with high penetration of household distributed PV. The trading system includes a physical layer based on the power grid, an information layer based on a virtual agent network, and a market layer based on a continuous double auction (CDA) mechanism combined with market clearing. By using simulation of trading experiments, a community with 60 houses and 50% PV occupancy is studied as a case. Results show that in one day, 62.5% of the surplus PV electricity of all prosumers actually can be consumed within the community. Through P2P electricity trading of this part of electricity, total incomes of prosumers can increase by 11.5%, and total expense of all users decrease by 7.5%, resulting in that the net expenses of the whole community decrease by 13.8%. It is concluded that P2P electricity trading can unite the whole PV community as a bigger prosumer, and make every residential house in the community share the profits from local PV consumption, which could promote the subsidy-free development and grid parity of household distributed PV in the future.

There are prototypes of social housing massively built in contrasting climatic conditions, generating thermal comfort needs that are difficult to satisfy by the users themselves. Variation of indoor air volume in living spaces where the use of air conditioning and natural ventilation strategies provides elements to improve thermal comfort conditions. This research shows the thermal performance located in a representative social housing according to Mexico's National Housing Commission. Operative temperature results from a benchmark case were compared to six Virtual Evaluation Models, using the Dynamic Thermal Simulation tool Design Builder® from the perspective of probability. The main objective was to determine the minimum use of active systems with different indoor air volumes and improve comfort conditions to promote sustainable living in social housing. The analysis was conducted under an adaptive comfort range according to three different climate conditions in Mexico adopting a Numerical Theoretical Method. The main findings can be divided into two parts: a) the impact of the indoor air volume on thermal performance was evidenced in a proportion of time in three representative climates of the central region of Mexico, and b) no relationship was found between indoor air volume and thermal comfort in sub-humid cold climate; in sub-humid temperate climate, the same number of comfort hours was found in two different models, and in sub-humid warm climate, an inversely proportional relationship was found between indoor air volume and the comfort hours. This findings implies a greater knowledge relative to what we know about sub-humid cold, temperate and warm climates.