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Low-rise vernacular masonry buildings are vulnerable to damage from extreme flooding. This paper presents findings from a study based in Sri Lanka assessing the structural resilience of non-engineered single-storey houses constructed with either fired clay brickwork or cement block masonry walls. A structural survey of flood-damaged houses enabled characterisation of masonry materials, and development of proposals to improve the lateral load capacity of masonry walls. The structural survey revealed that a combination of low-quality masonry units and variable thickness of mortar beds may have contributed to flexural failure due to the hydrostatic pressures during flood events. An experimental programme investigated the impact of differing masonry units and mortar thickness on masonry properties under dry and saturated conditions. A simple retrofit method has been developed, using reinforced renders, that enhances sectional flexural capacity by over 11 times, offering greater resilience to lateral flood loads. The impact of this research study will have direct welfare benefits for Sri Lankan people living in flood-risk areas, reducing the risk of structural collapse and enabling people to remain safely in their homes during flood events.

This paper gives a review on concrete by adding various types of steel fibre, glass fibre and recron fibre into the concrete and to make comparison of test results. The sudden application of the lateral load demands for a flexible structure which under goes large inelastic deformation during the load. One of the techniques to achieve the ductile structure by adding fibre in the concrete. The addition of the fibre can considerably improve the strength and ductility of structural components, resulting in a considerable energy absorption capacity. In this thesis, an experimental examination of the behaviour of internal beam-column joints under seismic circumstances is given according to IS: 13920–1993. RC, SFRC, HFRC-1, and HFRC-2 are the four internal beam column joint specimens in the experimental programme. The load bearing capacity, load–deflection behaviour, stiffness degradation factor, energy dissipation capacity, ductility factor, and cracking properties of internal beam column joints are investigated. Important inferences will be formed based on the experimental results, and the benefit of employing fibres in the beam column joint region will be well proven.

Due to the increasing demand for renewable clean energy, there has been rapid growth in the development of offshore wind energy resources in recent years. The majority of offshore wind turbines are founded on single, large-diameter, open-ended pipe piles known as monopiles. The design of these piles is often done using the p–y method, which models the soil simply as non-linear springs placed along the pile length and assumes the pile to behave as a one-dimensional beam. To develop a design method that accounts for three-dimensional pile–soil interaction and that is applicable to general conditions, a series of finite-element (FE) analyses covering a wide range of pile dimensions, wall thicknesses, slenderness ratios, load eccentricities, sand types and sand relative densities were performed using an advanced sand constitutive model. In this paper, a set of equations is proposed that can be used to estimate the critical pile length, Lcrit (the pile length beyond which the pile lateral capacity no longer increases), the lateral capacity, H, and the lateral load–rotation curve for monopiles. The proposed method produces estimates of the lateral capacity of monopiles that are in very close agreement with those from the FE analyses.

Piles (kinds of geotechnical structures) are used for resisting various lateral loads including earthquakes and inclined loads. Hence, these structures' behavior under lateral load should be studied. Therefore, this investigation studies the lateral deflection (LD) of piles under different situations. 192 physical models were carried out by consideration of the most important factor on the lateral deflection amounts in dried sandy soils. Besides, a model of the Elman Neural Network (ENN) - Improved Arithmetic Optimizer (IAO) algorithm was suggested for predicting the piles' lateral deflection. For the intention of comparison, the Elman Neural Network model and Particle Swarm Optimization - Artificial Neural Network were utilized in lateral deflection amounts estimation. For evaluating the proposed model validity, some parameters like Variance Account For, determination coefficient, and Root Mean Squared Error were estimated. The results showed the ENN-IAO method is more reliable for lateral deflection prediction in a small-scale pile in comparison to the ENN method and PSO-ANN model.

Several provinces in Canada have modified the live load model specified in national bridge design codes to account for locally permitted trucks. Manitoba similarly introduced a live load model for the design of provincial bridges in accordance with AASHTO LRFD, the Modified HSS-25. This article presents truck weight datasets and methods used to develop Manitoba-specific live load statistics to conduct a reliability analysis for three typical simply supported structure types: precast prestressed concrete box girder, precast prestressed concrete I-girder and steel girder. The average reliability indices ranged from 4.69 to 4.95 with respect to the AASHTO LRFD live load statistics used to calibrate the code and 4.65 to 5.04 with respect to the Manitoba statistics. The results demonstrate a level of safety that exceeds the code requirements, indicating that structures designed to the HSS-25 potentially possess the structural capacity to withstand increased vehicular load effects for the considered bridge types.

Changes in the size and weight regulations for trucks have been used to improve their productivity, safety, and operational performance in Canada. In response to these changes, bridge design codes undergo modifications to envelop the potential range of trucks in operation. A five-decade timeline is presented to: (i) document how bridge codes and their live load models have evolved, with a focus on the Manitoba-specific HSS-25 truck; and (ii) discuss how responsive the bridge design codes have historically been to changes in truck size and weight regulations. While at times bridge codes are released in conjunction with expected regulation changes, there is often delay in the issuance of those codes. Assessments of the current truck fleet, which now includes long combination vehicles (LCVs), may be a consideration for future bridge live load models.

The need for constructing a shallow or deep foundation (e.g. piles) in a mechanically stabilized earth (MSE) wall for superstructure support has increased. However, the performance of laterally loaded piles within the MSE wall and their interaction with soil and reinforcement are not fully understood. Limited full-scale tests and numerical studies have been conducted to evaluate the behavior of laterally-loaded piles within MSE walls. In this study, thirteen reduced-scale model tests were performed to investigate the effects of changing the wall configuration (wall height, and reinforcement spacing and length) and the pile location on the performance of the pile-MSE wall system under static lateral loads. This experimental study found that the piles in high walls could develop larger maximum compressive and tensile strains. Low walls resulted in larger wall facing deflections and maximum tensile strains in the geogrid reinforcement. Small reinforcement spacing and long reinforcement length resulted in higher pile lateral load capacities, smaller wall facing deflections, and smaller reinforcement tensile strains. The pile offset from the back of the wall facing is a critical factor that affected the pile capacity, the wall facing deflection, the reinforcement tensile strain, and the lateral earth pressure distribution behind the wall facing.

Nowadays, the demand for using jack-up platforms to carry out a large percentage of deep-water oil and gas exploration is steadily increasing. The response of jack-up platforms to the severe dynamic loads that may be encountered during the structure life is not examined enough. Therefore, this study attempts to investigate the response of jack-up platforms performance under the effect of dynamic loads due to wave, wind, earthquake and tsunami forces using the finite element method for two models with the lowest and highest hull elevations. The jack-up platform is located in the Gulf of Mexico. Earthquake accelerations are applied to the model in high and moderate seismic levels. In addition, tsunami waves are applied to the platform in three different directions at 0°, 45° and 90°. This study utilised Airy's linear wave approach to assess the surface elevations and wave kinematics. The reference wind velocity is 10 knots at 10 m over the mean water level. Results indicate that the dynamic response of the structure is affected by the height of the platform and by the increase of the platform hull elevation. The combination of the El-Centro earthquake, dead and live loads provides the major impact on the platform at the lowest (70 m) and highest (85 m) hull elevations. The comparison of all result proves that the jack-up platform hull under high earthquake intensity and tsunami waves with 45° has experienced maximum deformation. Moreover, raising the deck will increase the response of the dynamic load and displacements but will negatively affect the platform.

The construction of noncircular tunnels at shallow depths has become increasingly common in urban areas to efficiently utilize underground space. In general, noncircular tunnels may cause high stress concentrations and large settlements. In addition, the stability of shallow tunnels affected by the structural loads/surcharge loads on the surface is too significant to ignore. This study presents new analytical solutions to efficiently predict the stresses and displacements around shallow noncircular tunnels in rheological rock. The key factors, i.e., any viscoelastic characteristics of the surrounding rock, arbitrarily distributed loads exerted on the ground surface, arbitrary tunnel shapes and pressures exerted at the internal tunnel boundaries due to liners or water pressures, are fully taken into account. A noncircular tunnel in the half-plane was mapped into an anulus by employing the conformal mapping function. Then, the elastic solutions of the problem are obtained by complex variable theory combined with the mapping function. Based on the elastic solutions and the extended corresponding principle for the viscoelastic problem, time-dependent analytical solutions are obtained for the ground assuming any viscoelastic models. The analytical solutions are verified by the good agreement between the analytical and FEM results under the same assumptions. Then, a parametric study is finally performed to investigate the influence of the location or range of the surcharge, tunnel burial depth and lateral pressure coefficient on the ground stresses and displacements. The proposed analytical solution can provide insight into the mechanical behavior of shallow noncircular tunnels under surcharge loads, as well as an alternative method in the preliminary designs of future shallow tunnels.

Concrete filled double-skin steel tubular (CFDST) column comprises two inner and outer steel tubes with infill concrete between tubes. CFDST columns are used in many structural systems such as offshore structures and high rise buildings. The aim of this research is to examine the performance of composite frames composed of CFDST columns and steel beam under the influence of lateral loading. The frames were modeled and analyzed utilizing ANSYS finite element (FE) software. The linear and nonlinear behavior of steel and concrete materials and confinement effects of inner and outer steel tubes on the infill concrete were considered in the analysis. Three key parameters were considered in the present study. They are the axial load and slenderness ratios of CFDST column as well as linear stiffness ratio of the beam–column. The effects of these parameters on the behavior of the composite frames were evaluated comparatively. Load-deformation responses were achieved for various cases of the investigation. The verification of the developed FE model was evaluated by considering the analysis results with the experimental data existing in the literature. The findings attained from the FE modeling were in consonance with the experimental results. Besides, it was observed that the above parameters had a substantial influence on the load-displacement relationship and the performance of the studied composite frames.

In this article, an attempt has been made to compare AAC blocks as a replacement material to red bricks. Different forms of experiments have been used to equate the properties of AAC blocks to those of other blocks. AAC blocks have a lower density than standard bricks for experimental verification, but they have a higher compressive strength than traditional bricks, which tends to reduce the structure's dead load. It has been found that the expense of construction is lowered by 15% to 20% when AAC blocks are used instead of other construction materials.

R-factor (Response reduction factor) is an important design consideration in seismic design of structures, which is assumed to consider energy dissipation of structures by means of ductility. So, proper estimation of R-factor is required for seismic design of structures which will account for ductile deformation so that suitable detailing of reinforcement can be done. In case of irregular structures, where the torsion effect is the predominant factor, accurate estimation of R-factor is even more difficult. Therefore, in the present study, an attempt has been taken to determine R-factor for plan irregular buildings. A G +7 storied building is considered and irregularity effect has been incorporated by C and L-shaped configuration. The design of the buildings has been done following Indian Standards. Modeling and analysis have been done using SAP2000. Plastic hinges have been considered to represent material nonlinearity. Mander’s confinement model has been considered. Nonlinear Static (Pushover) following FEMA 440 methods with uniform lateral load variations has been done. Initial tangent stiffness has been followed in equal area method during bi-linearization of pushover curve. It can be stated that apart from material strength and geometrical configuration, performance requirement of the buildings is the most important factor for selection of R-factor.

The challenge is to search out the economic structure system of high-rise buildings within the Indian scenario. This document covers numerous steel systems: moment-stabilizing frame system, composite frame system, luggage rack system with stabilizing belt, structural wall frame system, and frame tube system. Once coming up with multi-storey buildings, truss systems, cluster piping systems for high-rise buildings, lateral hundreds (wind or unstable loads) are principally chargeable for demolition, determining structural systems for high-rise buildings. To form the drift as slight as possible, the beams and columns should be more stiffed. In an exceedingly building with a bit of floor range, the lateral load seldom affects the rise within the building and, therefore, increases size. The part structure considers the aspect load and the doable arranging of the structure. In alternative side load resistance systems beneath study, the force frame’s side displacement is the highest. The lateral displacement of the double frame is the smallest, and the lateral displacement of the slippery wall system is slightly beyond that of the double system.

The dynamic behavior of tall building structures is unpredictable under lateral loads. The key concern of tall building design is controlling deflections under lateral loads like earthquake loads or wind loads. There are many structural forms to resist lateral loads; the outrigger system is one of the best structural forms for effective lateral load resistance in tall buildings. Since the location of the outrigger enormously influences the dynamic behavior of tall structures, the present research focused on finding the optimum location of the outrigger along with the height of the structures. For this contest, a numerical study is carried out with five structural models of different aspect ratios. The aspect ratio of the models considered is 0.91, 0.61, 0.45, 0.36 and 0.30. All five models are designed as per Indian codes, IS456, and IS1893. For the observation of the dynamic performance of the five models, the outrigger truss without any belt truss is placed at different heights of the building. For each position, the dynamic performance of the 3D structure is observed. The study is made to compare the reductions in displacements, inter-story drifts, and overturning moments for the buildings with and without outriggers. This study focus on the change of the position of the outrigger for greater resistance to lateral loads depending upon the aspect ratio of the buildings. The analytical results have been studied to find out the optimum location of the outrigger, along with the height of the structures with different aspect ratios. It was concluded that the optimum position of outrigger truss without belt truss is at 65 to 80% of the height of the building for aspect ratios between 0.45 and 0.95.

One of the major durability issues of Reinforced Concrete (RC) structures is the steel reinforcement corrosion. Its effect needs to be evaluated on the lateral load capacity of the structures for understanding their seismic performance. In the present paper, the precise FE modelling and simulation of corroded RC frames subjected to lateral loads and its validation with full scale shake table tests on corroded RC frames is demonstrated. The rebar corrosion is induced in RC frames by accelerated impressed current technique and shake table tests are performed by simulating real time earthquakes with increasing excitation till failure of the frames is achieved. The tests showed that there was higher degradation of the frequency of the corroded structure with respect to pristine structure with increase in earthquake excitation levels. Numerical simulation of the tests is carried out using 2D micro-modelling, incorporating the effect of bond strength reduction, reduction in rebar diameter and decrease in mechanical properties of corroded steel in the model. Nonlinear static pushover analysis is performed to evaluate load displacement characteristics of the corroded and uncorroded frames and the results are compared with dynamic pushover obtained from shake table tests. It was observed that compared to un-corroded frame there is 13% reduction in the failure load due to earthquake excitation for the 7.5% corroded frame and numerical results for 10% corroded frame showed 22% reduction in the lateral load carrying capacity.

In this article, we propose a model predictive active power control (APC) enhanced by the optimal coordination of the structural loadings of wind turbines (WTs) operating with fully developed wind farm (WF) flows that have extensive interactions with the atmospheric boundary layer. In general, the APC problem, that is, distributing a WF power reference among the operating WTs, does not have a unique solution; this fact can be exploited for structural load alleviation of the individual WTs. Therefore, we formulated a constrained optimization problem to simultaneously minimize the WF power reference tracking errors and the structural load deviations of the WTs from their mean value. The wind power plant is represented by a dynamic 3-D large-eddy simulation model, whereas the predictive controller employs a simplified, computationally inexpensive model to predict the dynamic power and load responses of the turbines that experience turbulent WF flows and wakes. An adjoint approach is an efficient tool used to iteratively compute the gradient of the formulated parameter-varying optimal control problem over a finite prediction horizon. We have discussed the applicability, key features, and computational complexity of the controller by using a WF example consisting of 3x4 turbines with different wake interactions for each row. The performance of the proposed adjoint-based model predictive control for APC was evaluated by measuring power reference tracking errors and the corresponding damage equivalent fatigue loads of the WT towers; we compared our proposed control design with recently published proportional-integral-based APC approaches.

Reinforced concrete infilled frame with brick masonry panel is becoming more common in recent days. Now a days this type structural frame is implemented mostly on the high-rise building because those buildings should be able to resist the lateral loads such as wind and seismic force hence, infilled frames are one of the most common lateral loads resisting system. In this study, two-dimensional single-bay, single-storey gabled infilled specimens were analyzed under static loading. The behavior of the reinforced concrete (RC) bare frame, RC infill frame with cement mortar interface is used and analyzed. In particular, the paper discusses the lateral stiffness of the frames and gives a comparative study between gabled frame and rectangular frame under static lateral load with varying parameters based on the obtained results such as displacement, lateral stiffness, bending moment and lateral load are carried out.

Technological advancements in the development field compare to a more extensive transformation in urban lifestyle and in designing of structure. The presentation of new reinforcement materials in concrete, notably iron, steel, and other reinforcing components, has sparked interest in enhanced concrete technology. Concrete reinforcement dates back hundreds of years, and several progressions are blended to ad lib the solid's qualities through reinforcement. Based on this finding from the prior research examines, a change in reinforcement patterns is done to explore the deflection of concrete of M30 grade under elevated temperature. For the assessment, middle and corner frame are considered with the amount of steel of four numbers of 16 mm diameter for column and 8 mm diameter is utilized for the stirrup at 150 mm C/C spacing. A live load of 3.5 KN/m and a wall load of 14.7 KN/m is applied on the compression member. Using finite element software ABAQUS the analytical works are done. The steady state analysis of eight models of bare frame, infill frame with different bay openings, infill frame with different storey openings are done. The frame model is created and meshes using the C3D8T meshing type for an 8-node thermally coupled brick mesh with a mesh size of 25 mm. The simulation results are used to explore the effects of temperature with loading condition on the reinforced concrete frame, and its structural properties are provided as performance graphs in the result section. The model is simulated utilizing steady state analysis and characteristics like as deformation and failure rate under thermal load.

The brief introduction of steel and steel-concrete composite bridges presented in Chapter 1 and the revision of the nonlinear material behavior of the main bridge components presented in Chapter 2 provide a useful background on bridges and the material behavior of the components of the bridges. It is now possible to detail applied loads acting on steel and steel-concrete composite bridges, which is highlighted in this chapter. This chapter presents different loads acting on railway and highway bridges and the stability of the bridges when subjected to these loads. The chapter starts by showing the dead loads of steel and steel-concrete composite bridges that are initially estimated for the design of bridges. Then, the chapter presents the live loads from traffic as specified in the American and European codes. After that, the chapter presents the calculation of horizontal loads and other loads acting on the bridges such as centrifugal forces, seismic loading, collision forces, and temperature effects. In addition, the chapter presents the load combinations specified in the current codes of practice to predict the worst case of loading for the calculation of different straining actions in the bridge components. Furthermore, different design approaches specified in the current codes of practice are highlighted in this chapter. Finally, the chapter addresses the main issues related to the stability of steel and steel-concrete composite plate girder and truss bridges such as buckling behavior of compression members, stability of thin-walled steel plate girders, lateral torsional buckling, and composite plate girder behavior. Once again, when highlighting the main issues related to the stability of the bridge components, it intends to review and present the issues based on the design rules specified in the current codes of practice, with particular focus on the Eurocode as an example. Overall, the author hopes that this chapter paves the way to the design examples of different bridge components presented in Chapter 4 .

Structures on incline ground are vulnerable to earthquakes because of irregularities in plan and elevation. The structural configurations on slopes have been observed, with stepback and stepback-setback configurations being the most common. In mid to high rise buildings, shear wall and C-shaped shear wall cores are commonly used lateral load resisting components. The current research focuses on comparing the seismic performance of L-shear walls(LSW) at the corners, C shear-walls at core(CSW) and Reinforced concrete-filled steel tube column (RCFST) at corners and cores in stepback, and stepback-setback configurations buildings considering the base of the structures fixed designed for Indian codes using response spectrum analysis. The structural analysis tool ETABS 2017 was used to perform seismic analysis. Buildings on a hill slope with various configurations are studied: bare frame, concrete blockwork infill, LSW full bay at corners, LSW half bay at corners, CSW and RCFST column at corners and core. The characteristic parameters such as base shear, forces in the columns at the ground floor, storey drift, maximum storey displacement, time period, the bending moment in columns at every floor level and storey shear in structures will be determined and analysed for the different structures at the sloping ground. Structures with corner LSW perform better than buildings with centrally located shear walls at the core, whereas LSW at half bay in the corner and RCFST columns at corners and core serve the dual objective of space constraint and improved performance.

Monoblock prestressed concrete sleepers are the most dominant type of sleepers in ballasted railway tracks. As such, it is important to provide optimized designs to the concrete sleepers and the associated fastening systems to ameliorate railway safety and to save both capital and maintenance funds. Therefore, a three-dimensional finite element railway model was created and verified. The response of both concrete sleepers and fastening components to coupling vertical and lateral loading was quantified. Such loading form typically occurs at horizontal railway sections causing damage to the railway track components. The influences of the sleeper spacing, elastic modulus of the rail pad, and friction coefficient at the contact surfaces of the rail and sleeper with the rail pad under varied lateral loadings were investigated. The interaction influence between parameters was thoroughly discussed. Among the studied parameters, the finite element model outcomes showed that the elastic modulus of the rail pad and the coefficient of friction are the most critical parameters with respect to the lateral load path and the local response of concrete sleeper and fastening system, especially at high lateral loadings. By using a relatively soft rail pad (elastic modulus = 100 MPa), the concrete material remained below the compressive and tensile fatigue limits even under high lateral loadings provided that the coefficient of friction remains limited to 0.3. By contrast, for a given lateral to vertical loading ratio, a continuous increase in the developed stresses of the concrete material and rail pad was detected as the elastic modulus changed from 100 MPa to 2000 MPa and the coefficient of friction increased from 0.3 to 0.9. The influence of sleeper spacing on the behaviour of railway tracks is only tangible on the distribution of the vertical wheel load. Lastly, the peak stress magnitudes of the ballast bed could be increased by 50% as the lateral to vertical loading ratio reached 0.6 compared to the case where the lateral load is absent. The experience gained from this article would help to formulate specific recommendations to improve the design of concrete sleepers, fastening systems, and ballast bed.

This paper attempts to examine the effect of the scaling of ground motion records on the seismic responses of base-isolated buildings by using the three scaling methods including the ASCE 7–10, acceleration spectrum intensity, SIa, and the spectral acceleration corresponding to the effective period of the base-isolated structure at the design displacement, Sa(TD). The buildings had steel moment-resisting and X-braced systems and were isolated with lead rubber bearings (LRBs) at the base. Near-fault ground motions with Forward Directivity (FD), Fling-Step (FS) and No Pulse (No P.) characteristics as well as far-fault ground motion records were studied in this paper. The discrepancy in the seismic responses as well as the effect of the pulse period in the case of pulse-like ground motions was scrutinized for the three scaling methods. Also, the response spectrum analysis (RSA) and static method with the equivalent lateral force distribution prescribed in ASCE 7–10 were carried out. The results indicate that the RSA as well as the static analysis, prescribed in ASCE 7–10, underestimates the story shears of the base-isolated buildings. The underestimation increases in the case of the FF and No P. ground motions having a large amount of spectral acceleration in the higher modes region. Also, the underestimation increases with the increase in the height of the base-isolated buildings as well as in the case of the moment-resisting frames compared to the X-braced ones. Finally, by means of the results derived from the time history analyses, a formula was proposed to determine the lateral force distribution along the height of the base-isolated buildings with LRBs considering the characteristics of the isolator and the structure for different types of the ground motions.

Researchers and design engineers are increasingly interested in castellated beams because of their ability to provide greater flexural strength with lower dead loads, as well as provide services and cost-effective structures. The influence of castellation on the bending strength and stiffness of the hot-rolled steel Square Tubular Beams (STBs) and Castellated Tubular Beams (CTBs) with simply supported end conditions were investigated in this study. Totally eight bending tests were carried out on hollow tubular beams with and without castellation under three point bending. The STBs with a nominal steel tube thickness of 2.5 mm are castellated in a hexagonal pattern. The ultimate moments, moment versus mid-span deflection response curves, and failure patterns are provided as part of the test results. The bending tests show that the flexural capacities and stiffness of the hollow tubular sections significantly increased due to the castellation process. Finite element (FE) models of STBs and CTBs were established by including the material and geometric nonlinearity as well as the measured geometric imperfections. The FE models established show good agreement with the experimental test in terms of ultimate bending strength, moment vs. mid-span deflection response, and failure modes.

Reinforced concrete (RC) shear walls constitute a lateral load resisting system which is utilized in medium-rise and high-rise buildings. Recent earthquakes and corresponding studies have highlighted the importance of understanding the performance of reinforced concrete shear walls. Hence, there is an essential need to estimate the response of RC shear walls. However, predicting the response of the RC walls is difficult in this form due to the complex nature of the problem. In this research, a hybrid technique, the artificial neural network (ANN) and Simulated Annealing (SA), is considered to solve such complicated problems. (SA) algorithm is utilized to determine the optimal number of neurons of ANN and the percentage of data that should be used in the training and testing set. 14 learning algorithms are used and their performance is compared. The database, which is utilized in this study, consists of 150 RC shear walls. The coefficient of determination (R2) and root mean square error (RMSE) values of the best ANN model (ANN with Conjugate gradient backpropagation with Fletcher-Reeves updates learning algorithm) were found to be 0.97 and 1.66, respectively, which demonstrate a high capability of the SA-ANN algorithm in predicting RC shear walls’ responses.

Bolts, nails and screws are the most commonly used connectors in steel-to-timber composite (STC) system. Glued-in rod (GIR) as one kind of connectors for timber structures, is also supposed to be used as the connections in STC system. This paper reports an experimental campaign on steel plate-to-timber connections with single GIR and wood screw fastener aiming to investigate the shear performance of the connections. The experimental results indicated that under lateral load, the fasteners exhibited “one hinge” or “two hinges” deformation modes typically, which are greatly associated with the fastener anchorage length. The load-relative displacement curves were generally characterized by a linearly increasing response followed a yield plateau and a secondary non-linearly increasing response indicating the so-called rope effect of the fasteners. The fastener anchorage length showed significant influence on the load capacity of the screwed steel plate-to-timber connections while did not affect the load capacity of the steel plate-to-timber connections with GIR fasteners. The initial stiffness and ductility of the steel plate-to-timber connections were obviously influenced by the fastener anchorage length. A finite element (FE) model was developed to simulate the joint behaviour and the simulation results are in good agreement with test results. Finally, the load-carrying capacity of the steel plate-to-timber connections with screw and GIR fasteners was predicted by the calculation model reported in Eurocode 5 and a new proposed calculation model, respectively.

The Qiupu River Bridge is the first suspension bridge with the application of a novel anchorage of root pile foundation. The static behaviors of the bridge were studied in this paper. Before the bridge was opened to traffic, the statically loaded field tests of the bridge have been carried out to check its load-carrying capacity. Then, a finite element (FE) model of the bridge was developed and calibrated to the measured initial equilibrium configuration. The efficiency of the FE model has been verified by comparing the calculated results of the model to the measured ones under the live loads, which indicates that calibration of the FE model to the initial equilibrium configuration is crucial to the construction of a baseline FE model. Based on the verified FE model, the influences of anchorage displacements on the bridge loading behavior were studied. Furthermore, a simplified analytical method was proposed to analyze the mechanism of structural responses under the anchorage horizontal displacements. The comparison of analytical results with FE results revealed a good agreement. It is demonstrated that the horizontal displacement of the anchorage of suspension bridges affects the structural responses more obviously than the vertical displacement, while the pylon is sensitive to the anchorage displacement. The deflection of the bridge deck results from the pylon displacement, which is caused by the unbalanced main cable force between the main span and side span. It is reasonable to take the internal force of pylons as the controlling condition of anchorage displacements. Finally, based on the analytical method, the parametric studies reveal that increasing the sag-to-span ratio and side-to-center span ratio can reduce the displacement and internal force of pylons caused by the anchorage displacement.

The experience of past earthquakes has shown that the beam to column joints in moment frames is one of the key members in the path of lateral load transfer and their weak performance causes the destruction of the whole structure. The use of FRP composites in strengthening and repairing these members as an effective solution has a special place in the construction industry. However, the separation of FRP composites from the concrete surface has become the biggest challenge facing researchers. In the present study, the grooving method has been used to install CFRP composites and the ability of this method to delay or eliminate the separation of FRP composites in shear strengthening of reinforced concrete beam-column joints has been investigated. In this paper, four external concrete beam-column joints with a scale of 1/2 have been made in the laboratory. There are two specimens as controls, one of which has special seismic details in accordance with ACI regulations and the other specimen does not have seismic details. The two retrofitted specimens also lack seismic details, and CFRP composites are employed for the retrofit. In one of the retrofitted specimens, CFRP composites are installed on the concrete surface in the usual way, and in another specimen, CFRP composites are installed on the concrete surface by the grooving method. The specimens are subjected to cyclic loading with incremental amplitude. The results were evaluated by comparing hysteresis curves, envelope curves, energy dissipation, stiffness reduction and cracking pattern. The results show that the applied method eliminates the separation phenomenon and a significant increase in bearing capacity, ductility and energy dissipation was observed.

Shear walls are the primary lateral load-carrying elements in tall buildings. The composite shear walls with double steel plates and filled concrete are composed of two steel plates with studs inside, they were developed to enlarge the building space, and to delay the appearance of cracks by using the steel plates as formwork. Double skin composite wall panels can offer high strength and robustness while improving the convenience of construction, with great potential for application in nuclear power plants

Precast concrete frame structure with nonrectangular columns are becoming attractive to researchers and engineers owing to advantages such as avoiding column protrusion from walls and saving space. This paper presents the experimental investigation of a full-scale precast concrete frame structure with L-shaped columns (PCFS) subjected to reverse cyclic loading. The precast connection adopted grouted anchor connection. As a comparison and benchmark, one full-scale monolithic sample (RCFS) was also tested. The results indicates that the greater steel ratio in the grouted anchor connection region leads to a high local stiffness of the elements, which contributed to delaying occurrence of the first crack at the grouting holes. The failure mode, lateral load capacity, stiffness degradation, load-carrying capacity degradation, energy-dissipating capacity, ductility and interlayer residual deformation were compared between two specimens. PCFS specimen exhibited comparatively better hysteretic behavior, energy-dissipating capacity, residual deformation-resisting capacity and ductility. For RCFS and PCFS specimens, the peak load difference was within 7%. About 15% increases in ductility were observed for PCFS specimen compared with RCFS specimen. The test results would provide reference for the application of the precast concrete structure with nonrectangular columns in the new residential buildings.

The present study deals with the assessment of surcharge induced consolidation effect on the shear strength of clayey soil and the pile capacity. The study was performed at a construction site located near the coastal area of Tamil Nadu, India. A series of laboratory tests were performed on the disturbed and undisturbed soil samples collected from the site after doing few in-situ tests. The pile capacity was estimated as per the Indian Standards using the properties of soil assessed from the geotechnical investigation and compared with that of field load test on pile. The bored piles were cast upto a depth of 16 m which pass through clayey soil with soft to hard consistency and rest on very dense sandy soil layer. Due to very low subgrade reaction modulus of top soil layer, the lateral capacity of 450 mm diameter pile tested was lesser than the designed. Hence, the design was revised with the 600 mm diameter pile. From the detailed load test program on the 600 mm diameter piles during fixed interval of time, it was found that the site development by 2 to 3 m earth filling induced the consolidation and improved the shear strength of the soil upto a depth of 5 m. The vertical and lateral load capacity of pile was also improved to a maximum of 15% and 70%, respectively after 2 years. The results of the investigation proved the importance of time-dependent behaviour study on the pile capacity assessment.

Reinforced concrete two-way flat slabs are considered one of the most used systems in the construction of commercial buildings due to the ease of construction and suitability for electrical and mechanical paths. Long-term deflection is an essential parameter in controlling the behavior of this slab system, especially with long spans. Therefore, this study is devoted to investigating the validation of the ACI 318-19 Code long-term deflection limitations of a wide range of span lengths of two-way flat slabs with and without drop panels. The first part of the study includes nonlinear finite element analysis of 63 flat slabs without drops and 63 flat slabs with drops using the SAFE commercial software. The investigated parameters consist of the span length (4, 5, 6, 7, 8, 9, and 10m), compressive strength of concrete (21, 35, and 49 MPa), the magnitude of live load (1.5, 3, and 4.5 kN/m 2 ), and the drop thickness (0.25t slab , 0.5t slab , and 0.75t slab ). In addition, the maximum crack width at the top and bottom are determined and compared with the limitations of the ACI 224R-08. The second part of this research proposes modifications to the minimum slab thickness that satisfy the permissible deflection. It was found, for flat slabs without drops, the increase in concrete compressive strength from 21MPa to 49MPa decreases the average long-term deflection by (56, 53, 50, 44, 39, 33 and 31%) for spans (4, 5, 6, 7, 8, 9, and 10 m) respectively. In flat slab with drop panel, it was found that varying drop panel thickness t 2 from 0.25 to 0.75 decreases the average long-term deflection by (45, 41, 39, 35, 31, 28 and 25%) for span lengths (4, 5, 6, 7, 8, 9 and 10 m) respectively. Limitations of the minimum thickness of flat slab were proposed to vary from Ln/30 to Ln/19.9 for a flat slab without a drop panel and from Ln/33 to Ln/21.2 for a flat slab with drop panel. These limitations demonstrated high consistency with the results of Scanlon and Lee's unified equation for determining the minimum thickness of slab with and without drop panels. Doi: 10.28991/cej-2021-03091769 Full Text: PDF

A numerical finite element study is conducted in this paper to examine structural behaviour of high strength RC columns exposed to biaxial and uniaxial lateral displacement histories with constant axial load. The numerical analysis of 24 models was made using ABAQUS / CAE. The comparison between numerical analysis and experimental results shows good agreement through validations. The considered parametric study involves determination of the longitudinal reinforcement ratio, total cross-sectional area of confinement steel (Ash), and uniaxial and biaxial cyclic shear load. Numerical analysis results show that an increase of longitudinal reinforcement for a uniaxial and biaxial lateral historic load will significantly increase maximum and ultimate load of columns, corresponding deflections, number of cycles at maximum and ultimate loads, and initial stiffness Ki, while the effect of transverse reinforcement is less pronounced. The columns load and deformation capacity decreases significantly with application of biaxial cyclic shear load, compared with uniaxial load. Also, this effect reduces with an increase in longitudinal reinforcement ratio (%ρl) and Ash.

Recent studies in wave energy have highlighted the need for a structured innovation approach in wave energy converter (WEC) design because cost-of-energy estimates have remained high. One such innovation being investigated by the National Renewable Energy Laboratory is WEC geometry control, which uses control surfaces in combination with an oscillating surge WEC (OSWEC) to increase device availability and power generation while limiting structural costs. This study performs the first analysis of annual performance for a novel OSWEC with geometry control to understand how the geometry control affects availability, annual power generation, and structural loadings like the power-take-off (PTO) torque or surge foundation force. Device hydrodynamic coefficients are calculated using linear potential theory for six geometry configurations. A nonideal PTO system is assumed and quadratic viscous damping losses are considered. Annual performance is evaluated and compared for three U.S. wave energy sites. The WEC geometry and PTO system are controlled on a sea-state basis to optimize for power capture while remaining under limits set on motion amplitude and structural loads. Results indicate that geometry control can increase availability up to 25 days in an average year depending on design limits, increase average power generation, and significantly reduce peak structural loads.

Military vehicles are sometimes required to transit bridges owned and operated by civilian bridge authorities. Using available data regarding the gross vehicle weight and associated axle loads of military traffic, live load factors, calibrated to the Canadian Highway Bridge Design Code, are proposed for bridge design and evaluation. This paper recommends live load factors for three categories of military vehicles: (i) wheeled-transport vehicles; (ii) wheeled-fighting vehicles; and (iii) tracked-fighting vehicles. The values are derived for interior girders of simply supported slab-on-girder bridges subjected to a single lane of traffic loading and are believed to be generally applicable for other structural elements and bridge types. Inherent differences between fighting vehicles, which are heavily armoured, and transport vehicles, which although armoured have high payloads, suggest that highway bridges should be evaluated separately for military fighting vehicles and military transport vehicles using distinct live load factors.

In bridge analysis, designers calculate maximum bending moment, MT, and shear force, VT, of a bridge girder under truck loading, then use available truck fraction, FT to generate the longitudinal live load effects. This Thesis presents structural analysis of different girder configurations subjected to CL-W truck loading. Girder geometries include single-, two-, three- and four-span girders. The maximum shear, deflection and moments were plotted and then used to develop equations to represent their values. Furthermore, a software was developed to perform composite steel I-girder design. The software optimizes the I-girder size based on CHBDC design procedure. Using the developed software, a parametric study was conducted to determine the required composite moment of inertia, moment of inertia of the bare steel section and steel web area to satisfy all design requirements. Empirical equations for these three properties were developed to assist bridge designers in estimating steel I-section sizes for contract bidding.

Numerical modelling of the soil in seismic design of structures is always a daunting task. The goal of this article is to develop a simplistic numerical modelling technique for shallow founded buildings on compliant soils. An existing large-scale experimental research (TRISEE) was used for calibration. The physical model comprised of a rigid square foundation placed on a sand bed connected to a rigid column and was subjected to a dynamic sine loading. The results from the TRISEE experiment are well known and commonly used by researchers in this field, yet none of the numerical studies were conducted considering the loose sand case. Nonlinear link elements and linear springs were used for representing the soil. It was determined that the soil behavior is highly influenced by the stiffness, selected hysteresis model, and the p-y curve. Considering the software limitations, numerical models represent the experimental behavior in a good manner. Based on the results obtained from the experiment, a case study on a steel frame building with SSI effects included was conducted. Considering the results from this research, the authors recommend implementation of SSI effects into the building’s design phase since they exhibit unfavorable impacts on the seismic behavior and can lead to underdesigned structural elements. However, it has to be emphasized that certain limitations exist due to simplified modelling approaches that were used for this research.

Load and resistance factor design (LRFD) for serviceability limit state (SLS) of laterally loaded drilled shafts was explored for transmission line structures in sand, and the SLS resistanc...

The submerged floating tunnel (SFT) is a newly developed traffic structure for crossing the long waterway. On the basis of the vehicle–tunnel coupled vibration, the vortex-induced effect o...

International audience; During the previous OC511 project, state-of-the-art mid-fidelity engineering tools for floating wind systems were found to consistently underpredict the nonlinear, low-frequency responses of semisubmersible offshore wind platforms, leading to substantial errors in the structural loads because of low-frequency surge and pitch resonance. To examine this underprediction, a coordinated investigation with computational fluid dynamics (CFD) simulations and model-basin experiments was carried out. Both investigations involved a fixed and simplified OC5-DeepCwind semisubmersible in bichromatic waves. The wave excitations—especially the nonlinear, difference-frequency excitation—on the structure from the CFD simulations were compared to the experimental measurements for validation, with uncertainty analyses for both the experimental and the CFD results. Further, the wave excitations on each column of the semisubmersible were measured separately in the experiment, allowing the validation of the CFD results to be done on a per-column basis. Overall, the CFD predictions of the difference-frequency excitations agree with the experimental measurements, suggesting the CFD solutions can be used as a reference for tuning and improving the engineering-level tools and can provide a means to better understand the underprediction at low frequencies.