Lateral Load-carrying Capacity Research Articles

Numerical investigation on the behaviour of Post-Tensioned Mechanically Stabilised Earth Walls (PT-MSEW)

This study reports on a numerical investigation on the behaviour of an innovative retaining wall system named Post Tensioned Mechanically Stabilised Earth Wall (PTMSEW). In the proposed system, Post-Tensioning (PT) technique was integrated into the common retaining wall and the Mechanically Stabilised Earth Wall (MSEW) construction method to improve the performance of MSEWs and limit their failure modes. The variables of this study were wall height, PT force, pre-cast segment size, surcharge load, foundation size, and soil reinforcement length. The study found that incorporating PT stress into the MSEW improved the performance of the retaining wall by decreasing horizontal displacement of the wall face, soil reinforcement tensile forces, and backfill settlements and significantly enhanced the passive resistance of the wall. The introduction of a small amount of PT force prevented local failures caused by the relative movement of face segments. It was observed that by applying only a small level of post-tensioning, the lateral load-carrying capacity and passive resistance of the proposed PT-MSEW system can be significantly improved over that of its conventional counterpart. This opens new possibilities for the use of MSEW in the construction of taller retaining walls.

Experimental, numerical and analytical studies on full-scale cold-formed steel center-sheathed shear walls subjected to combined loading

Conventional cold-formed steel wall systems suffer from low lateral loading-carrying capacities and stiffnesses, which represent the main barrier to their use in multi-story buildings. To address it, a cold-formed steel center-sheathed shear wall (CFSCSSW) system with higher lateral load-carrying capacity and better lateral structural performance is proposed. This paper presents experimental, numerical, and analytical studies on the behavior of the proposed CFSCSSW subjected to combined vertical and horizontal loads. Firstly, a full-scale test was conducted, with the test setup, loading procedures and measuring instrument reported in detail. The obtained test results, including the load-carrying capacity, failure mode and strains, were fully analyzed. Then, finite element modeling was conducted to simulate the experimental observations, and parametric studies were carried out to investigate the influences of different geometric and loading parameters on the behavior of CFSCSSWs. Finally, a three-strip model with a variable position on end studs (TSM-VPC) was proposed for CFSCSSWs and shown to accurately simulate the direction of the tensile field within the sheathing and also resulted in high accuracy in calculating the load-carrying capacities, followed by a design example.

Parametric study of reinforced interlocking brick wall under cyclic loading

Mortarless interlocking brick walls are a new form of masonry structures that can be efficiently constructed. In this study, a detailed numerical model of an interlocking brick wall under quasi-static in-plane cyclic loading is generated and verified with laboratory test data. The influence of the vertical reinforcement placement methods, i.e., grouted vs. unbonded, and the influence of wall-to-brick size ratio are firstly investigated. Parametric studies are then carried out to quantify the influences of axial precompression level, shear span ratio and friction coefficient between bricks on the lateral load-carrying capacity, deformation capacity, and energy dissipation capability of the studied mortarless interlocking brick walls subjected to in-plane cyclic loading with analytical equations summarised for predicting the resistance performance of this type of mortarless interlocking brick walls under in-plane cyclic loading.

Lateral Load-Carrying Capacity of Low-Rise Reinforced Concrete Walls in Nuclear Safety-Related Structures

Nuclear safety-related structures are crucial for ensuring the safety of nuclear facilities and preventing the leakage of radioactive materials, with the primary structural component being low-rise reinforced concrete (LRC) walls. These walls are required to carry combined in-plane axial and horizontal loads, making the accurate prediction of their lateral load-carrying capacity particularly important. In this study, six LRC walls with aspect ratios between 0.33 and 1 were tested and a model for the prediction of the lateral load-carrying capacity of LRC walls was established based on the observed failure mode and plastic limit theory. The parameter in the model was calibrated using the obtained results in this test along with a database containing 131 walls in the literature. Compared to the equations in the American standard ACI 349 and the French standard RCC-CW, the proposed equation is most suitable for assessing the lateral load-carrying capacity of LRC walls in nuclear safety-related structures. The calculated values of the proposed equation exhibit a ratio closest to 1 when compared to experimental values and possess the minimum degree of variation. The computational results reveal that the proposed equations in this study exhibit superior precision and stability.

Enhancing seismic resilience: A proposed reinforcement technique for historical minarets

Historical minarets are culturally and architecturally significant structures, often susceptible to substantial damage over time due to different load conditions. Therefore, the reinforcement of such buildings holds paramount importance. This study presented a proposal for strengthening historical rubble stone minarets, exemplified by the minaret of Murat Pasha Mosque in Erzurum, Turkey. A finite element model of the minaret was constructed to comprehend its behavior, with the suggested reinforcement method integrated into this model. The impact of the proposed reinforcement on the minaret's behavior was comprehensively investigated through various numerical methods including modal analyses, pushover analyses, and non-linear dynamic analyses. The analyses revealed that the proposed reinforcement increased the first mode frequency of the minaret by approximately 9.8%. Additionally, it was observed that the reinforcement method augmented the minaret's lateral load-carrying capacity by 58%. Consequently, it was concluded that the proposed reinforcement technique effectively enhances the minaret's resilience under demanding conditions, potentially preventing damage. The proposed reinforcement configuration also significantly alters the collapse mechanism of the minaret, as evidenced by the dynamic analysis results, facilitating a more controlled mode of failure. In this regard, it provides a more secure solution by enhancing the minaret's resilience in an earthquake, thereby reducing environmental safety risks. In conclusion, this study contributes to preserving this invaluable cultural heritage by offering an effective reinforcement method to enchance the seismic resilience of historical minarets. Future research endeavors may further refine these reinforcement techniques and explore alternative material options.

Quasi-Static Cyclic Tests of Precast Two-Column Bent Connected with Both Grouted Splice Sleeves and Grouted Central Tenon

Owing to the advantages of accelerated construction, reduced traffic disturbance, and enhanced quality control, precast segmental two-column bents are extensively utilized in urban and highway bridges, particularly in areas of low-to-medium seismicity. However, the application of this technique in high-seismicity regions is limited owing to insufficient knowledge about the seismic performance of such precast bents. To address this, the present study investigates the seismic performance of precast segmental two-column bents, focusing on the connection of “grouted splice sleeves and grouted central tenon”, namely the proposed GSS-GCT connection. For this purpose, three large-scale two-column bent specimens were fabricated and subjected to quasi-static cyclic tests: one cast-in-place bent, one precast two-column bent with conventional grouted splice sleeves, and another with the GSS-GCT connection. The benefits of the GSS-GCT connection under high seismic activities were demonstrated regarding lateral load-carrying capacity, displacement ductility, energy dissipation capacity, and residual displacement. Moreover, five levels of damage states were qualitatively and quantitatively divided based on experimental observation, which can be evaluated with lateral displacements. Furthermore, seismic assessments of the two-column bents were obtained using the capacity spectrum method. The proposed GSS-GCT connection could significantly improve the seismic performance of precast segmental two-column bents under high-level earthquakes.

Bonding Behavior of Cement Mortar Retrofitting for Adobe Masonry Wallette with Groove, Wire Mesh, Shear Dowel, and Sticky Rice Paste.

Damaged adobe masonry is essential to retrofit not only for continued use by less developed populations but also for historical preservation and vernacular landmark maintenance. Coating mortar on adobe can greatly improve the static load-carrying capacity of adobe masonry Wallette. Four retrofitting methods are carried out to enhance the cooperation of mortar and adobe; these four methods focus on the factors of roughness, shear dowel, and mesh size and a novel biological and traditional Chinese binder, sticky rice pulp. The mortar coating with the four bonding enhancement methods can greatly increase both the compressive and lateral load-carrying capacities, with a maximum improvement of 177 and 743%, respectively. The bonding strength has a negative effect on the compressive load-carrying capacity; on the other hand, it has a positive effect on the lateral load-carrying capacity. A range analysis is also carried out, which shows that the shear dowel depth has the greatest effect on both load situations, followed by the wire mesh size.

Behaviour and design of coupled steel-concrete composite wall-frame structures

This paper explores the lateral load-carrying behaviour of coupled steel-concrete composite (SCC) wall-frame structures, which comprise concrete-filled steel tubular (CFST) columns, composite beams and composite walls. Both experimental and numerical studies were conducted. The experimental programme includes one single-storey bare frame structure and three single-storey coupled SCC wall-frame structures. The experimental results showed that applying the composite wall can significantly increase the lateral load-carrying capacity of the entire structure. It was also evident that increasing the wall width and lowering the structural height can effectively enhance the lateral load-carrying capacity. The modelling approaches in ABAQUS and OpenSees were proposed to conduct the finite element (FE) analysis. In particular, ABAQUS was used to build single-storey coupled SCC wall-frame structures to assess the effects of several parameters, such as beam stiffness, the thickness of steel tubes and wall faceplates, wall width, concrete grade, steel grade and axial load ratio. It was found that increasing the thickness of steel tubes and wall faceplates as well as wall width can effectively increase the lateral performance of the structure but increasing the steel beam stiffness only results in limited improvement. Increasing the steel grade can improve the lateral performance of the structure much more significantly than the concrete grade. When the axial load ratio reaches 0.6, the lateral strength of the structure is greatly reduced owing to the P-Δ effect. Moreover, one multi-storey bare frame structure and three multi-storey coupled SCC wall-frame structures were constructed in OpenSees as a case study. The multi-storey coupled SCC wall-frame structures display extraordinary lateral load-carrying capacity by analysing the curves of base shear force versus roof drift ratio. Besides that, instead of the nominal inter-storey drift ratio, the destructive inter-storey drift ratio together with the roof drift ratio are recommended to assess the multi-storey coupled SCC wall-frame structures in order to avoid overconservative design.

A Comparative Computational Investigation on the In-Plane Behavior and Capacity of Dry-Joint URM Walls

ABSTRACT Predicting the lateral load-carrying capacity of dry-joint unreinforced masonry (URM) walls is often challenging due to the complex interactions between the governing parameters (i.e. geometrical and mechanical properties). The capacity and behavior of dry-joint URM walls depend on boundary conditions, size and location of the openings, bond pattern, vertical load, and aspect ratio, among other factors. In this context, the present research investigates the effect of bond pattern, aspect ratio, vertical load, and boundary condition on the in-plane (IP) behavior and capacity. Two computational methods, the discrete element method (DEM) and micro limit analysis (micro LA), are employed. Through a comprehensive parametric assessment, the result indicates a good agreement between the two approaches. The computational investigations underline the direct relationship of the IP capacity of walls with respect to aspect ratio and applied vertical pressure. Furthermore, fixed-no rotation boundary condition is associated with the increased IP capacity. Finally, a simple analytical equation is proposed to predict the lateral capacity of dry-joint URM walls.

Influence of Infill on Reinforced Concrete Frame Resting on Slopes under Lateral Loading

When compared to traditional reinforced concrete constructions on level surfaces, buildings situated on hills with slopes require additional consideration, particularly when seismic loading is an important factor. In hilly slopes, the ground-level columns of structures have different heights due to the nature of the slope, which leads to a short column effect. This paper represents an experimental and analytical investigation of the behaviour of reinforced concrete frames and their response in sloped regions of hills, in which global retrofitting techniques were adopted by providing solid infill in the short column effect zone for the columns in the same storey of differentheights. Numerical analysis was conducted on how infill affected the short column effect under lateral cyclic loads. It was discovered that compared to bare reinforced concrete frames, masonry infill greatly increased the lateral load-carrying capacity by up to 50%. In the meantime, the frame’s ability to dissipate energy increased linearly. After infill was added to the frame with the short column effect, the reinforced concrete structure’s different reactions, including ultimate load displacement, crack pattern, energy dissipation, and energy absorption, were examined. With the addition of a solid infill, the reinforced concrete structure’s lateral strength and energy dissipation capacity were increased by 2.45 times. The damage development on the reinforced concrete frame with infill and the short column effect was less impacted by lateral stress than the reinforced concrete frame without infill.

Effect of Precompression and Material Uncertainty on the In-Plane Behavior of URM Pier–Spandrel Systems

Theoretical and experimental studies on loadbearing masonry walls have shown the significant influence of the axial load level (i.e., precompression) and wall aspect ratio on in-plane lateral resistance. Nonetheless, the impact of the precompression and spatial variability of the material properties needs to be further investigated at the scale of walls with openings. This study presents a stochastic analysis of unreinforced (URM) pier–spandrel systems subjected to both axial loads on piers and lateral loads, considering the spatial variation in material properties. A discontinuum-based computational model was utilized to assess the force–displacement behavior of a benchmark pier–spandrel structure under different vertical precompression levels on piers. A total of 750 simulations were carried out to propagate material uncertainties in lateral load analysis. The proposed modeling strategy, based on the discrete element method, explicitly represents joint openings, sliding, and crushing phenomena at the contact points defined between the adjacent discrete rigid blocks. According to the validated computational modeling strategy, meaningful inferences were made regarding the effect of the precompression level on the maximum displacement and ultimate lateral load-carrying capacity of the benchmark URM pier–spandrel system. The results showed that vertical pressure on piers had considerable influence on the displacement ductility of the system while yielding less variation in the displacement capacity. Furthermore, the appealing feature of the spatial probabilistic analysis is noted in the variation in the lateral load-carrying capacity of the structural system.

Precast concrete wall-raft connectors for increasing the lateral load capacity: An experimental and analytical approach

Precast structural walls and rafts commonly resist lateral load in structures owing to improved traits and faster construction. The behavior of five different types of precast reinforced concrete structural wall and raft connection systems is evaluated in this study. In all five configurations, the cyclic load is applied in the wall systems to observe the lateral load-carrying capacity and hysteretic characteristics. The damage and failure patterns were assessed. To confirm and contrast the behavior of the proposed precast structural wall and raft connection systems with the experimental findings, FEM analysis was used. Only shear and flexural cracks were observed. The specimen with 12 mm dia rods has the maximum load carrying capacity of 10.23 kN in the negative cycle, which is 57% more than the specimen without grouting and connector. The suggested connection can improve the resistance behavior in all key directions by absorbing more energy than precast walls under dynamic load.

Numerical analysis of timber frame wall filled with hemp concrete

This paper presents a numerical study of the lateral load-carrying capacity of hemp concrete as infill material in timber frame walls. The parameters that significantly affect the lateral resistance of hemp walls were investigated. For this purpose, vertical stud timber frame walls measuring 2.5 m in height and 1.2 m in length were used as the benchmark to validate earlier experimental work. A numerical study of three timber walls filled with hemp concrete was conducted to assess the effect of wall length on the lateral load-carrying capacity of hemp concrete. Three vertical stud timber frame walls with a standard height 2.5 m and different lengths (1.2 m, 1.6 m and 2.4 m) were investigated using Abaqus software. This study confirms, firstly, that the length of a timber wall plays a significant role in the lateral load-carrying capacity of hemp concrete. Secondly, the contact and bonding between the hemp concrete and timber wall have a significant effect on the lateral load-carrying capacity of hemp concrete as infill material in timber frame walls. It was clear, from the numerical results, that increasing the length of the wall significantly increases the contribution of hemp concrete to lateral resistance. Good contact and bonding between the hemp concrete and the timber elements also increase the lateral strength of the hemp wall.

Behavior of Pultruded Glass-Fiber-Reinforced Polymer Beam-Columns Infilled with Engineered Cementitious Composites under Cyclic Loading

Glass-fiber-reinforced polymer (GFRP) is an advanced material that has superior corrosion resistance, a high strength-to-weight ratio, low thermal conductivity, high stiffness, high fatigue strength, and the ability to resist chemical and microbiological compounds. Despite their many advantages compared with traditional materials, GFRP sections exhibit brittle behavior when subjected to severe loading conditions such as earthquakes, which could be overcome by infilling the GFRP sections with concrete. This paper presents the results of an experimental investigation carried out on the cyclic response of a GFRP beam-column infilled with high-volume fly ash engineered cementitious composites (HVFA-ECC) consisting of 60%, 70%, and 80% fly ash as a replacement for cement. Finite element analysis was also conducted using robot structural analysis software, and the results were compared with the experimental results. The mechanical properties of GFRP sections presented are the compressive strength of ECC, the direct tensile strength of ECC determined using a dog-bone-shaped ECC specimen, the hysteresis behavior of the beam-column, and the energy dissipation characteristics. The lateral load-carrying capacity of beam-column GFRP infilled with HVFA-ECC consisting of 60%, 70%, and 80% fly ash was found to be, respectively, 43%, 31%, and 20% higher than the capacity of GFRP beam-columns without any infill. Hence the GFRP sections infilled with HVFA-ECC could be used as lightweight structural components in buildings to be constructed in earthquake-prone areas. Also in the structural components, as 70% of cement could be replaced with fly ash, it can potentially lead to sustainable construction.

The effect of geometric dimensions on the lateral bearing capacity of the masonry arches

The roofs of historic structures and old buildings are frequently covered using 5&7 brick arches. Since the design of these arches is usually done against gravity loads, they will probably be vulnerable to lateral loads. The estimation of the lateral bearing capacity of 5&7 brick arches is the main goal of this study, along with investigating the effect of geometric dimension parameters on the lateral bearing capacity of these arches. The models of the examined arches are in accordance with 5&7 arches of the low slope and steep slope types. The spans studied in this research are equal to 2.5, 4.5, 6.5, and 9.5 m, and the results have been tested for a case study, the main porch of Gonabad Grand Mosque in Iran. The specifications of the building materials used in this research were determined using laboratory studies, and all analyses were performed by ANSYS software. Evaluating the ratio of lateral load-carrying capacity to the weight of the structure for different arches showed that the optimal ratio of the thickness of the pier to the spans for low slope and steep slope 5&7 arches was about 0.24.

Performance of steel bridge piers filled with lightweight concrete under cyclic loading

Abstract Concrete-filled steel tube columns are widely used in civil engineering structures due to their excellent ductility, energy absorption capacity, ultimate load-bearing capacity, and seismic behavior. In this paper, a numerical study modeling of eight lightweight concrete and conventional concrete filled steel tubes was carried out using ABAQUS software, and the lateral load-carrying capacity of square and circular steel tubes under cyclic load was compared. The quarter and one-third height of the tubes was filled with concrete with respect to the pier's height, to improve the base performance of the piers. The results show that the capacity of steel tubes filled with lightweight concrete increased by 40%–70% regarding energy absorption. The square tubes showed better performance than the circular tubes in terms of yielding load, yielding displacement, and energy dissipation.

Cyclic Behavior of L-Shaped RC Short-Limb Shear Walls with High-Strength Rebar and High-Strength Concrete

Six RC short-limb shear walls with an L-shaped section, constructed with high-strength rebar and high-strength concrete, were loaded to destruction with pseudo-static loading. Experimental results were discussed and compared with L-shaped RC short-limb shear walls with high-strength horizontal rebar in detail. Different failure modes were obtained, such as flexure-dominated failure for specimens with an aspect ratio of 2.8 and 2.15 and bending-shear failure for specimens with an aspect ratio of 1.75. With a decrease in the aspect ratio, ductility decreased, whereas with an increase in the axial compression ratio, the load-carrying capacity increased but ductility decreased accordingly. An obvious pinching effect was found in specimens with a smaller aspect ratio and a higher axial compression ratio. Using high-strength longitudinal rebar and high-strength concrete can obviously improve the lateral load-carrying capacity of walls; and using high-strength horizontal rebar can obviously improve the ultimate deformation capacity. The average ultimate drift ratios of HPLW and LW far exceeded the specification requirements of the Chinese GB50011-2010 code.

Shear strengthening of brick masonry walls with opening

In this study, results of testing eight clay brick walls are presented. The walls were tested under distributed vertical load and gradually increased lateral load. The walls consisted of one solid wall, two walls as control and five walls with openings strengthened by using: RC frame around the opening, RC frame with the lintel extended to the ends of the wall, steel channel frame around the opening, confining the wall with RC frame, and near-surface mounted bars. Results showed that all the strengthening techniques increased lateral load-carrying capacity, ductility and toughness compared to the non-strengthened walls. The highest increase in shear strength was for the wall strengthened with steel frame around the opening 88%, followed by the wall strengthened with NSM steel bars 56%. From the load deflection curves energy dissipated by the walls during loading was calculated. Walls with interior steel frame, outside confinement, interior RC frame showed the highest increase in energy dissipation over the control wall by 470, 268, and 250% respectively. Calculation of shear strength based on existing equations is presented, and an analytical model is proposed for predicting lateral shear strength of walls with opening. The results show fair agreement with test results.

Seismic Behavior of Lap Splice Reinforced Concrete Frames with Light-Steel-Framed Walls and Different Anchorage Details

In this study, the seismic behavior of light-steel-framed, infill-walled, lap splice reinforced concrete (RC) frames covered with steel sheets was experimentally investigated. A total of four RC frames to 1/5 scale, single-span and having two stories were produced for the experiments. One of the frames was a double-skeleton light-steel-framed infill-walled specimen having an anchorage spacing of 130 mm in the columns and the connection of the steel sheet plates to the profiles was made using self-drilling screws, and the other one had a 65 mm anchorage spacing in the columns and the connection of the steel sheet plates to the profiles was made using bolts. Two reference specimens were used. These are the bare frame and the aerated concrete infill wall frame. Tests of these specimens were carried out under constant axial load and reversed-cyclic lateral load. As a result of this study, it was observed that double-skeleton systems contributed positively to the lateral load-carrying capacity, energy-dissipation and initial stiffness of the RC frame. Additionally, it was concluded that the strength and energy-dissipation feature of the specimen could be increased by reducing the anchorage spacing in light-steel-framed wall systems and by attaching the steel sheet plate to the profiles using bolts.

Investigation of cyclic behavior of full-scale tree-like hollow structural section columns with infilled concrete

The cyclic behavior of tree-like hollow structural section (HSS) columns with infilled concrete was experimentally and numerically investigated. A full-scale column, with the height of 3.7 m and the treetop plan dimension of 4 m × 3 m, was designed and manufactured according to a practical engineering prototype. The column was composed of a petal-shaped trunk using a concrete-filled steel tubular (CFST) section, four primary branches using a circular CFST section, and twelve secondary branches using a circular HSS. The column with a capacity protected reinforced concrete foundation was tested under combined constant axial compression and cyclic lateral loading through a specifically designed setup. The cracking and spalling of the reinforced concrete foundation were observed initially, followed by yielding of the bottom end of the primary branches when the story drift ratio reached 1.00%. The specimen failed by fracture of the full penetration groove welded splices in the petal-shaped trunk embedded in the foundation when the story drift ratio reached 3.00%. A detailed finite element analysis model for the tree-like column was then established and verified. Parametric studies were conducted to investigate the influence of the axial load level (0.016–0.3), filling range of concrete (including no filling, partial filling, and overall filling), steel yield strength (235–460 MPa), and the height to width ratio of the petal-shaped trunk (0.75–3.14). The results showed that the higher the filling height of concrete was, the greater the lateral load-carrying capacity and stiffness of the specimen were, but the filling height after reaching the secondary branches hardly affected the mechanical properties of the specimen. With the increase of the axial load level, the load-carrying capacity and deformation capacity decreased. Both the filling range and the height to width ratio of the petal-shaped trunk could change the failure mode of the tree-like column. Finally, some design considerations were proposed.