Column Removal Scenario Research Articles

Experimental investigation on alternate load path mechanisms in double-span beams with unsymmetrical span lengths and reinforcement ratios

In the design and assessment of reinforced concrete (RC) structures against progressive collapse via single column removal scenarios, also known as the “alternate load path (ALP) method”, the development of secondary mechanisms in double-span beams, i.e. compressive arch action (CAA) and catenary action (CA), has been thoroughly investigated and identified in many previous studies. The majority of the experimental tests were conducted on symmetrical double-span beams (identical span length and steel reinforcement ratio for both beams). However, variations in span length and reinforcement details of beams adjacent to one another are common in RC buildings due to architectural requirements. Hence, an experimental study with a total of 6 tests was conducted to investigate the development of ALP mechanisms (CAA and CA) in double-span RC frames with unsymmetrical 1) span length and/or 2) longitudinal reinforcement ratio. The 6 tests included 3 symmetrically-designed specimens that served as the baseline to facilitate comparison and quantification of the ALP development for the other 3 unsymmetrical continuous beams. The behaviour and development of ALP mechanisms in all the 6 specimens were analysed at structural level including general observations and measurements of the external forces, displacements, and strains. Last but not least, a simplified method that was initially developed based on symmetrical test data was employed to validate unsymmetrical test results, with the aim to provide a robust and simple tool for preliminary design considerations of the ALP mechanisms.

Progressive collapse resistance of RC beam-column substructures under fire conditions

To better understand the performance of reinforced concrete (RC) structures subjected to fire under column-removal scenarios, 3D numerical models were established to analyze the structural behavior of pre-loaded beam-column substructures under elevated temperatures in this paper. The temperature-dependent thermal and mechanical properties of concrete and steel were adopted to perform the sequentially coupled thermal-mechanical analysis in an ABAQUS/Explicit solver in a quasi-static manner. To capture the damage evolution of concrete and steel rebar, the concrete damaged plasticity (CDP) and ductile damage for metals (DDM) models were calibrated in the numerical model. Existing experimental data under both ambient and high temperatures were used to validate the feasibility of the proposed numerical model. The structural performance of the RC substructure under the loading stage and heating stage was investigated and the contributions of the resisting mechanisms were quantified using the analytical method. The effects of structural design features, such as reinforcement ratios, concrete strengths, span-to-depth ratios, and fire curves, on the collapse-resisting performance were analyzed in the parametric study. The chord rotation limit criteria regulated by the US Department of Defense (DOD) were utilized to identify the failure of substructures under fire and middle column-removal scenarios.

High‐performance metallic materials for applications in infrastructure and energy sectors

AbstractHigh performance steels, such as stainless steels, have many desirable characteristics that warrant their use in various sectors, including infrastructure and energy applications. This paper is concerned with two of such applications: (i) the use of stainless steel for large‐scale liquid hydrogen storage tanks, which is a requirement for the future hydrogen energy network, and (ii) the use of stainless steel in steel‐framed buildings to enhance their robustness under extreme loading conditions. The paper begins with a discussion of the technical challenges associated with the material behaviour of stainless steel storage tanks under extreme temperature and pressure conditions. It presents and discusses the results of a pilot experimental programme that investigates the mechanical behaviour of stainless steel 304 L material under cryogenic 20 k hydrogen environment. Next, to demonstrate the benefits of the strategic use of stainless steel in the key connection parts of steel‐framed structures, the paper presents the setup for a new test programme that investigates the behaviour of stainless steel beam‐to‐column connections, using A4‐70 bolts and EN1.4301 plates, under a column removal scenario. The numerical modelling prediction results of the specimens are presented, and comparisons with carbon steel counterparts are made and discussed.

Progressive collapse behaviour of advanced precast reinforced concrete joints with headed bars and plastic hinge relocation

This study proposed three types of precast concrete (PC) wet joints, viz., using Headed bars (Type H) to replace hooked bars, placing an Additional bottom bar layer (Type A), or implementing plastic hinge relocation method with X-bent bars (Type X) in the beam-joint region. These detailing features could compensate for negative effects caused by geometric discontinuity at the joint interface and prevent pull-out failure, as observed in conventional PC joints with hooked bars. An experimental investigation based on four interior joints showed that based on the steel content in Type H joint, by increasing respective steel contents of 7% and 8% in Type A and Type X joints, structural resistance to collapse could be enhanced by 34% and 47%, respectively. A fourth specimen of Type A joint incorporated the slab. It was found that although the slab could slightly enhance flexural resistance, it also reduced the joint rotational capacity. Subsequently, component-based joint models (CBM) with a bond-slip model of headed bars were proposed for the three types of PC joints and validated against the test results with satisfactory accuracy. Based on the validated CBMs, parametric studies were conducted for different cases, such as exterior and penultimate joints, under a penultimate column removal scenario. It was found that if the exterior column was too weak, compressive arch action and catenary action could not be effectively triggered, and column failure governed joint behaviour. Hence, to mitigate progressive collapse, the exterior columns and joints must be required to possess a sufficient level of horizontal resistance and stiffness.

Progressive collapse mode induced by slab-column joint failure in RC flat plate substructures: A new perspective

Majority of progressive collapse incidents of concrete flat plate structures were caused by slab overloading in the form of punching shear failure at a slab-column joint, which exhibit distinctive resistance mechanism from those triggered by column losses. Relevant studies on the slab overloading scenario are scarce. To fill this gap in research and to broaden the perspective on different collapse modes, an experimental test was conducted on a 1/3-scale 2 × 2-bay flat plate substructure specimen by applying an increased downward uniform load on the slab, until the structure was completely damaged following the initial punching shear failure at the interior slab-column joint and was unable to take any further load. In addition, the flexural capacity of the specimen was evaluated using the yield line theory, and an analytical model was also proposed to estimate the post-punching peak load of the specimen. Finally, the experimental results obtained from this study were compared to those of a similar test under an interior column removal scenario. Comparisons indicate that the specimen under the slab overloading scenario displays better collapse resistance than that under the column removal scenario. Nevertheless, the residual resistant capacity of the overloaded specimen may not be adequate enough to prevent the collapse of the entire structure after the initial punching failure.

Enhancement of collapse-resistant capacity of non-seismically designed RC frames using various CFRP strengthening schemes

The existing studies have demonstrated relatively weak robustness of non-seismically designed reinforced concrete (RC) frames against collapse than seismically designed RC frames, causing the demand of efficient strengthening schemes to enhance their collapse-resistant capacity. Therefore, this paper presents an experimental program aiming at strengthening the collapse-resistant capacity of non-seismically designed RC frames using carbon fiber reinforced polymer (CFRP). A total of seven sub-frames were tested, of which the penultimate column or edge column was notionally removed to replicate the initial damage caused by accidental loads. Two sub-frames without strengthening were tested first as reference tests. Similar to existing research outcomes, the referential sub-frames experienced premature rebar fracture at the beam ends near the removed column, resulting in a severe softening in load resistance. Whilst the load resistance could reascend, the fracture of the rebar at the beam ends near the side columns only allowed an insufficient mobilization of catenary action (CA). In addition, the side joint of the referential sub-frame representing a penultimate column removal scenario suffered significant damage. Subsequently, five strengthening schemes were applied to the referential sub-frame, they are designed to increase the compressive arch action (CAA) capacity or CA capacity, or both the CAA and CA capacities through CFRP strengthening. Test results demonstrated that the proposed strengthening schemes in this paper can efficiently increase the load resistance at the CAA and CA stages but failed to mitigate the severe load resistance softening. The strengthening scheme planned to increase the CAA capacity unexpectedly decreased the deformation capacity of the strengthened sub-frame due to premature fracture of beam rebar near the side columns. The strengthening schemes planned to increase the CA capacity or both the CAA and CA capacities could increase not only the CAA capacity but also the CA capacity. The enhanced load resistance at the CA stage was mainly attributed to the continuous CFRP strips attached to the soffits. Unfortunately, the energy method demonstrated that the dynamic load resistance of the tested sub-frames to prevent collapse was achieved at the CAA stage rather than the CA stage because of the severe load resistance softening. Thus, the efforts devoted to increasing the CA capacity by this paper were valid in a real collapse of building scenario. In addition, 113 available test results were collected to compare with the acceptance criteria in existing codes for collapse-resistant design. Based on the test results and comparison, design suggestions were given for the collapse-resistant design.

Dynamic response of planar frame sub-structure isolated by friction pendulum bearings subjected to a middle column removal scenario

The aim of this study is to investigate the dynamic response of planar frame sub-structure isolated by friction pendulum bearings subjected to a middle column removal scenario. The study presents and evaluates the dynamic structural behaviors, load transfer mechanisms, progressive collapse resistance, and dynamic increase factor (DIF) results of FPBs-isolated planar frame. The study explores the influence of the equivalent radius and friction coefficient of the FPB, as well as the peripheral constraints of the failed column. The results show that the compressive arching action (CAA) and catenary action (CA) cannot be fully developed for buildings isolated by FPBs due to the significant reduction in the lateral stiffness of the isolated layer caused by FPBs. The structural responses of planar frame isolated by FPBs are much larger than those of corresponding fixed-base buildings. The DIF of buildings isolated by FPBs initially decreases and then barely changes with an increase in the stabilized vertical displacement of the failed column. The presented fitted formula for DIF of planar frame isolated by FPBs describes the obtained results well. The friction coefficient and equivalent radius of FPBs show very limited influence on the dynamic response of planar frame isolated by FPBs under progressive collapse, but reinforcing the peripheral constraints of the failed column can enhance the progressive collapse resistance of isolated planar frame.

Simplified multi-scale simulation investigation of 3D composite floor substructures under different column-removal scenarios

The robustness of structures to withstand progressive collapse is a significant theme. However, owing to the restricted experimental conditions, some issues regarding 3D composite floor substructures under a column-removal scenario remain unclear, such as different column-removal scenarios, boundary constraints, loading schemes, floor numbers, reinforced concrete (RC) floors, and structural or nonstructural components. To understand these issues, a progressive collapse study on 3D composite floor substructures subjected to uniformly distributed load (UDL) is carried out based on simplified multi-scale simulation. A 2 × 1-bay concrete-filled steel tubular (CFST) column-steel beam-RC floor substructure is employed to investigate the structural robustness under the corner column-, penultimate-edge column-, and middle-edge column-removal scenarios. It is found that the vertical resistance for the corner column-removal scenario is reduced by approximately 10–20% compared to the other two scenarios. The 3D substructure resists progressive collapse via the flexural action (FA), the catenary action (CA), and the RC floor. Compared with the real boundary constraints, the fixed and hinged supports at the beam ends can overestimate the CA, and disregarding boundary constraints can overestimate deformation performance. Moreover, the concentrated vertical load (CVD) severely underestimates the robustness of 3D substructures. The floor number, RC floor, shear wall, and steel brace significantly influence the progressive collapse performance of 3D substructures.

Progressive collapse resistance and uncertainty analysis of post-tensioned steel frames

Post-tensioned (PT) steel frames with prestressed strands and replaceable energy dissipation angles demonstrate enhanced resilience during earthquakes compared to traditional steel frames. This study aimed to investigate the collapse resistance of PT steel frames in the different column removal scenarios. A macro model of a typical PT connection was developed using OpenSeesPy, a python library for the OpenSees finite element software framework. The model was validated by experimental results and applied to a six-story, four-bay office building. The collapse resistance mechanism of the building was analyzed in detail through a static pushdown nonlinear analysis, considering the edge column and middle column removal scenarios on the ground floor. A probabilistic analysis was conducted, incorporating uncertainty modeling and sensitivity analysis, to determine the effect of parameters on the collapse resistance of the structure. The collapse fragility functions corresponding to different structural performance levels were developed by the Latin hypercube sampling method with random pushdown analysis under the edge column removal and middle column removal scenarios, respectively. The uncertainty analysis results indicated that the PT steel frame investigated in this work has good collapse resistance.

Structural behaviour of 2D post-tensioned precast beam-column sub-assemblages subjected to column loss scenario

Many previous studies have investigated alternative load path (ALP) mechanisms of 2D reinforced concrete (RC) beam-column sub-assemblages under column removal scenarios. However, how precast and prestressed RC structures respond under a column loss scenario receives far less attention, as evident from a lack of published test data. Herein, five 2D post-tensioned precast RC sub-structures subjected to a middle column loss scenario were tested by multi-point quasi-static loading. In all the specimens, individual precast members such as beams and columns were joined together through wet connection. The study focused on investigating the combined effects of post-tensioned tendon (PT) and wet connection on load-resisting mechanisms and the influence of basic parameters such as unbonded and bonded PT, T-beam effect, and boundary conditions. The test results indicated that both unbonded and bonded parabolic-shaped PT significantly enhanced compressive arch action (CAA) and catenary action (CA) beyond basic flexural capacity, and also changed the plastic hinge mechanism in the precast beams. The specimen with unbonded PT could provide greater residual capacity than bonded PT, but the former was severely damaged by fracture of normal reinforcement and crushing of concrete rather than fracture of the tendon. In addition, the effects of T-beam and boundary conditions are discussed in detail. Finally, new design criteria for precast and post-tensioned concrete structures under column removal scenarios are proposed for structural engineers to take advantage of high-strength tendons and avoid failure at critical locations by precast joints.

Numerical Investigation of the Progressive Collapse of the Reinforced Concrete Wall-Frame Structures Considering the Soil–Structure Interaction

In this essay, the progressive collapse resistance of the reinforced concrete wall-frame structures was evaluated with and without considering the soil–structure interaction. The vulnerability of the frames against progressive collapse was investigated with the middle column removal scenario from the first story, based on the sensitivity index. To evaluate the effects of soil–structure interaction, the wall-frame structures along with the soil (hard soil) and foundation were simultaneously modeled in FLAC software and compared with the frames in Seismostruct software. The results showed that the sensitivity index decreased by considering the soil–structure interaction in the wall-frame structures. Afterward, a parametric study of the structures (foundation thickness) and substructures (soil types, soil densities, soil saturation conditions and soil layers) was performed. The results showed that with an increase in thickness of the foundation, the sensitivity index increased, and therefore, the condition of the structure would be more critical against progressive collapse. It was found that high groundwater levels in the subsoil can reduce its bearing capacity and lead to the damage to the structure. In addition, it was determined that by changing the substructure soil type from type 4 (Clay-MC) to type 1 (Rock), the use of layer 1 (SM) and layer 2 (SM-CL/ML (Very hard clay)-SM), and the soils with high density, the condition of the structures is better to prevent progressive collapse.

Experimental and Analytical Study on the Compressive Arch Action of Precast Concrete Assemblies with Monolithic Connections to Resist Progressive Collapse

Although the first progressive collapse event occurred in precast concrete (PC) buildings due to gas explosions, the behavior of PC buildings resisting progressive collapse is still unclear because related tests are few, and the types of PC connections vary. To study the progressive collapse resistance of monolithic PC beam-column assemblies under a middle column removal scenario, an experimental program including four PC assemblies and one reinforced concrete (RC) assembly is conducted. These PC assemblies contain different types of beam-column connections, including connections of lap-splice, 90° hook anchorage, U-shaped bar, and combined U-shaped bar and 30° hook anchorage. The test results demonstrate that flexural action, compressive arch action (CAA), and catenary action were mobilized in sequence in the beams of RC and PC assemblies. Thus, in general, the development of load resisting mechanisms of PC assemblies is similar to that of RC assemblies, although different types of connections may affect the magnitude of each mechanism. The PC assemblies with 90° hook anchorage and U-shaped bar connections attained a CAA capacity similar to that of the RC assembly, whereas the PC assembly with the combined connections had a greater CAA capacity because of plastic hinge relocation at the beam ends near the middle column. The PC assembly with lap-splice connections achieved the lowest CAA capacity due to the anchorage failure of the beam bottom rebar. However, this PC assembly attained the greatest catenary action capacity, because the beam bottom rebar did not fracture and could still develop tension. Subsequently, an analytical model is proposed to reveal the nature of CAA and to better understand the influence of critical parameters.

Axial–Flexural Interaction in Axially Restrained Beams in Progressive Collapse Column-Removal Scenarios

Progressive collapse alternate path scenarios are often characterized by restrained beam configurations that provide resistance to structural collapse after column removal. While various methods have been presented to model the behavior of restrained beams, opportunities exist for mechanics-based estimation of the complete static and dynamic load-deflection curves. This paper presents an axially restrained beam (ARB) model that incorporates axial–flexural interaction throughout the entire static load-deflection curve including the elastic material range, the plastic flexural dominant range, the range beyond plastic flexure with increasing catenary effect, and the full catenary range. Energy methods are applied to static load-deflection curves to determine dynamic load-deflection relationships. A parametric study was conducted to assess the accuracy of the ARB method compared to nonlinear, dynamic time history finite-element (FE) analyses. The model compares favorably to results of FE models with average estimates of dynamic deflection within 2.1% for ideal moment connections and 7.7% for configurations combining simple and moment resisting connections.

Experimental and Numerical Investigations of RC Frame Stability Failure under a Corner Column Removal Scenario

In recent decades, interest in the resistance of buildings and structures to progressive collapse has been increasingly sparked in research communities. Although several experimental, numerical, and analytical research projects on the robustness of building frames under a column removal scenario have been implemented, some aspects of this problem remain understudied. These aspects encompass failure mechanisms of reinforced concrete frames with slender columns, as well as criteria used to evaluate such failures. This paper focuses on experimental and numerical investigations of the structural behavior and failure of a scale reinforced concrete frame with slender columns under a sudden corner column removal scenario. In addition, we analyze the stability failure mechanism of a reinforced concrete frame with slender columns and the tangent stiffness criterion, which allow for evaluation of the ultimate state of a structure subjected to an accidental impact. A scale physical model of a reinforced concrete frame of a multistory building was designed and tested using the theory of functional similarity. For numerical study purposes, a finite element model was made that exactly the same as the test frame. We validated the findings by comparing simulation results and experimental data. The studies on the behavior of a reinforced concrete frame subjected to quasistatic loading with unequal concentrated loads identified the load transfer between columns through beams. Although these effects were minor in the frame under consideration, they can become more significant in cases of long-term loading. Numerical simulation and physical modeling of an accidental impact allowed for identification of the mechanism of load capacity exhaustion triggered by stability failure. Such failure was fragile. The moment of stability failure of the column of the experimental frame corresponded to the extremum on the force–displacement curve, indicating that zero tangent stiffness was reached. Hence, a criterion of tangent stiffness can be proposed for evaluation of the ultimate state of a structure subjected to an accidental impact.

Prediction of progressive collapse resistance of RC frames using deep and cross network model

Compressive membrane/arch action at small deformations and resistance evolution path at large deformations are two key factors in determining whether an RC frame structure can resist progressive collapse. In this study, two deep learning models based on deep and cross network (DCN) are developed to predict the progressive collapse resistance of RC frames. DCN model I is constructed to predict the compressive membrane/arch action resistance, while DCN model II is developed to predict the resistance displacement curve considering the dynamic effect. 464 records regarding structural collapse were collected through extensive literature review and stringent data filtering. They were randomly divided into 80% and 20% for training and testing the two models, to which the column removal scenario, with or without slab, boundary condition, beam net span, beam section, beam reinforcement ratio, and material property were selected as input features. Moreover, Shapley additive explanations (SHAP) method was introduced to interpret the proposed DCN model. The results indicated that the performance of DCN model I in predicting the compressive membrane/arch action resistance was satisfactory with an MAPE value of 10.66% and an R2 value of 0.9799, respectively, while being more accurate than the existing yield line theory and Park’s compressive arch calculation model. The proposed DCN model II can further capture the evolution of the dynamic resistance of RC frames accurately. The two DCN models have been deployed online to public for application.

Progressive collapse resistance of steel frame with beam to column transfer structure under a middle column-removal scenario

The application of Beam to Column Transfer Structure (BCTS) in practical engineering is more frequent to satisfy the requirement of space and economy of modern structure. However, the structure is unavoidable to increase the burden of the column in the lower floor, which will enlarge the risk of the structure subjected to progressive collapse. Hence, in order to explore the performance of the steel frame with BCTS on anti-progressive collapse, a numerical model is established by using Abaqus and it is validated by the test result. Based on that, a parametric analysis is carried out to discuss the effects of the Span to Depth Ratio (SDR) of the beams, and the Axial Compression Ratio (ACR) of the BCTS. The result indicates that the model with larger ACR leads to smaller load bearing capacity and Ultimate Deformation Capacity (UDC). Meanwhile, the model with larger SDR leads to smaller load bearing capacity but larger UDC. Moreover, it is found that it is inadvisable for unduly increasing the SDR to improve the contribution of the Catenary Action (CA) but decrease the contribution of the Flexural Action (FA). In addition, the better performances on progressive collapse can be observed as long as the models with the ACR is not greater than 0.06 in the RDS range from 11 to 19. Thus, the ACR of 0.06 is recommended as the limited value in structure design.

Performance of RC beam-column assemblies during and after elevated temperature to resist progressive collapse

In practice, fire is one of the accidental loads that can result in the progressive collapse of buildings but the commonly used alternate load path (ALP) approach often ignores the impact of fire. Therefore, numerical models based on the finite element software ABAQUS are employed to investigate the performance of reinforced concrete (RC) beam-column assemblies during and after high temperature to resist progressive collapse. The thermal–mechanical sequential coupling method is used for analysis. The effects of fire durations, boundary conditions (middle or penultimate column removal) and side column subject to fire are studied. Previous test results demonstrated that compressive arch action (CAA) and catenary action (CA) are developed in sequence to prevent progressive collapse for the assemblies at ambient temperature. However, the numerical results show that the in-fire assemblies could not develop CA owing to severe degradation of rebar elongation and thus, the load resistance of in-fire assemblies controlled by CAA capacity. Further increasing fire duration to 90 mins, the CAA capacity of the assemblies decreases over 70% compared with that at ambient temperature. Since the rebar can recover most of its mechanical properties after cooling down, the assembly after fire (i.e., exposed to fire then cooled down) can also successively develop flexural action (FA), compressive arch action (CAA) and catenary action (CA) to resist progressive collapse, which is similar to that of intact RC frame at ambient temperature. Under the penultimate column removal scenario, the exterior side column of the post-fire specimen suffers large eccentric compression failure, which causes the highest collapse risk.

Analysis of progressive collapse process of RC structures based on hybrid framework of FEM-physics engine

High-fidelity collapse process and reasonable debris accumulation and distribution after collapse are very critical to carry out post-disaster investigations and show why collapse happens. Moreover, previous researches on progressive collapse is more concerned with structural behavior in resisting collapse and pays little attention to the dynamic response after collapse criterion is reached. Therefore, a hybrid numerical framework is developed through combining the advantages of the finite element method (FEM) and the physics engine (PE), which provides new ideas for studying the full collapse process of structures. In this paper, based on previous work, such hybrid framework is further developed with efforts on element merging technique in the model mapping process from a FE model to a PE model and determination of connection constraints in the PE model. Then, a new Python-based interface program is developed to integrate the FE model using LS-DYNA and the PE model using Blender 3D. The accuracy of FEM-PE framework is verified by a collapse test of a flat plate structure, and an RC frame structure is designed for studying full process of progressive collapse. Results show that FEM-PE simulation can achieve accurate nonlinear structure behavior at small deformation and high-fidelity collapse at large deformation. To obtain reasonable debris accumulation, a single beam, column and slab should be meshed with the element number no more than 3, 2 and 3 × 3 in PE models, respectively. For a seismically designed RC frame structure, a single column removal scenario cannot initiate the collapse, but the simultaneous removal of a corner and a neighouring penultimate column generates the propagated collapse mode.

Analytical Model for Progressive Collapse of RC Frame Beam-Column Substructures Using Multi-Gene Genetic Programming

Establishing a concise and accurate analytical model is the key to developing a feasible progressive collapse design for engineering practice. However, existing models either focused on an individual force mechanism or required complicated computer programming. Among existing machine learning (ML) techniques, multi-gene genetic programming (MGGP) can be trained to obtain explicit formulas for engineering problems. In this study, a comprehensive database was established by data collection, Latin hypercube sampling and structural design, and was used to train the mathematical model for quantifying progressive collapse resistance of reinforced concrete (RC) beam-column substructures under middle column removal scenarios. Further, an energy-based error index was proposed to validate the accuracy of the MGGP model among others. The research outcomes can provide references for the development of simplified analytical models for calculating the progressive collapse progress of RC frame structures, and promote the development of the practical design method.

Analytical approach and design method for evaluation of compressive arch action of precast concrete beams

This paper proposes an analytical approach to predict compressive arch action (CAA) of precast reinforced concrete (PC) beams subjected to middle column removal scenario (MCRS). A beam-column joint with non-seismic detailing is employed in the prototype PC structures, which is a typical joint widely applied in low seismic-risk countries. However, under MCRS, a weaker sagging moment resistance of the precast interface near the removed middle column casts doubts on its structural performance. Based on particular details of the PC beams, the analytical approach is proposed to consider the influences of a potential plastic hinge at the PC interface, various precast interface locations, special precast reinforcing details and horizontal restraint conditions on the mobilisation of CAA. Furthermore, an easy-to-apply design method is developed by assuming linear relationships between bending moment, neutral axis depth and compression force of the PC beam. Reliability of the analytical approach and the design method is verified through comparisons between predictions and FEM simulations of typical two-span PC sub-assemblages with various design details. The comparison study suggests that both the analytical approach and design method can accurately predict the CAA capacity and corresponding displacement, as well as the maximum compression force and bending moment at PC beam ends. Finally, a parametric study is carried out to shed light on the effects of different precast interface locations and various common design details on CAA peak resistance. It is found that when the distance (L3) between the precast interface and the beam end interface does not exceed a threshold value (L3_c), increasing L3 can significantly enhance CAA capacity. However, when L3 exceeds L3_c, CAA cannot be further enhanced due to transformation of CAA mechanism. It also finds that the threshold value L3_c is highly influenced by reinforcement details, span-over-depth ratio and horizontal stiffness of the beam.