The topic of structural damage caused by fires following an earthquake (FFE) has been discussed extensively by many researchers for over a decade in order to bring the two fields closer together in the context of performance based structural engineering. Edinburgh University, Heriot-Watt University, Indian Institute of Technology Roorkee (IIT Roorkee) and Indian Institute of Science initiated a collaboration to study this problem under a UK-India Engineering Research Initiative (UKIERI) funded project. The first construction of a single-storey reinforced concrete frame at IIT Roorkee was completed in summer 2011; this is known as the Roorkee Frame Test 1 throughout this thesis. This thesis presents the modelling of the Roorkee Frame Test 1 using the finite element method and assesses the capability of the numerical methodologies for analysing these two sequential events. Both two and three dimensional finite element models were developed. Beam and shell elements were chosen for the numerical modelling, which was carried out using the general purpose finite element package ABAQUS (version 6.8). The variation in material properties caused by these two types of loading, including strength and stiffness degradation, compressive hardening, tension stiffening, and thermal properties, is implemented in the numerical modelling. Constitutive material calculations are in accordance with EC4 Part 1.1, and all loading is according to IS 1893:2002 Part 1 (Indian Standard). The time-temperature curve used in the analysis is based on data from the test carried out. The behaviour of the Roorkee Frame Test 1 when subjected to monotonic, cyclic lateral loading followed by fire is presented. The capacity of the frame when subjected to lateral loading is examined using a static non-linear pushover method. Incremental lateral loading is applied in a displacement-controlled manner to induce simulated seismic damage in the frame. The capacity curve, hysteresis loops and residual displacements are presented, discussed and compared with the test results. The heat transfer analysis using three dimensional solid elements was also compared against temperature distributions recorded during the Roorkee frame fire test. Based on the smoke layer theory, two emissivity values were defined. In this study, the suitability of numerical modelling using ABAQUS to capture the behaviour of Roorkee frame test is examined. The results from this study show that the 3D ABAQUS model predicted more reliable hysteresis curves compared to the 2D ABAQUS model, but both models estimated the lateral load capacity well. However neither model was able to simulate the pinching effect clearly visible in the hysteresis curves from the test. This was due to noninclusion of the bond slip effect between reinforcing bars and concrete. The residual displacement obtained at the end of the cyclic lateral loading analysis from the 2D ABAQUS model is higher than that seen in the test. However, the result in the 3D ABAQUS model matched the trend obtained in the test. The both columns appear to stiffen under the heating and the residual displacement seems to recover slightly. Lateral displacements, obtained in the thermo-mechanical analysis of the numerical models, show that thermal expansion brings the frame back towards its initial position. Finally, correlation studies between analytical and experimental results are conducted with the objective to establish the validity of the proposed model and identify the significance of various effects on the local and global response of fire resistance earthquake damaged of reinforced concrete frames. These studies show that the effect of tension stiffening and bond-slip are very important and should always be included in finite element models of the response of reinforced concrete frame with the smeared crack model when subjected to lateral and thermal loading. The behaviour of reinforced concrete frames exposed to fire is usually described in terms of the concept of the fire resistance which defined in terms of displacement limit. This study shows the global displacement of the frame subjected to fire recover slightly due to the thermal expansion during the heating.

Recent research on jointed unbonded post-tensioned precast concrete frames has demonstrated their superior seismic resistance. Inelastic rotation generated during large earthquake motions is accommodated through gap opening and closing at the beam-to-column connections in the frame. By applying the principles of Damage Avoidance Design (DAD), a steel-steel armoured connection has been demonstrated to be effective in protecting the precast elements from damage. The re-centring ability of the unbonded prestressed post-tensioned system allows the building to return to its original undeformed position after the earthquake with negligible residual deformations. This research experimentally assesses the biaxial performance of the unbonded precast beam-to-column joint and simplifies the steel-steel armoured connection details in the joint. The experimental results of both quasi-static unidirectional lateral loading tests and biaxial lateral loading tests conducted on a 80% scaled unbonded jointed beam-to-column joint are presented. The performance of the proposed simplified steel-steel connection is assessed. A theoretical model is developed based primarily on rigid body kinematics and is validated using the test results. A formulation is also developed based on St Vennants' principle, to estimate the effective stiffness of the precast concrete beams under bidirectional rocking. Based on the experimental findings, improvements to the steel-steel armoured connection and joint details are proposed.

The consulting firm Atkins has developed a tool to help constructers plan urban areas but the tool is lacking data about embodied carbon in Sweden. The embodied carbon is the total carbon dioxide equivalents that are emitted from the material used in constructing a residential building as well as the energy used at the construction site and during demolition. In this thesis, the embodied carbon for a concrete framed building and a wooden framed building is calculated and presented. The mapping of embodied carbon for the two different framed buildings is done with a life cycle assessment perspective. In order to structure the studied system, the life cycle of the buildings is divided into three stages. The first stage includes data and calculations about the extraction and manufacturing of the most common building materials as well as the transportation to construction site. Stage 2 presents information about theon-site construction which includes, among other things, use of machines for constructing a residential building. In the third stage, data regarding demolition and end of life management are presented and calculated. All these three stages are added and a value for total embodied carbon for concrete framed residential buildings and wooden framed ones is presented in the result. The final result shows that the studied concrete framed residential building contains more embodied carbon than the wooden framed one. Further, stage 1 represents the largest part of embodied carbon, 87% for the concrete frame and 84% for the wooden frame, and stage 2 represents a very small part for both types of buildings, 1% for the concrete frame and 2% for the wooden fame.

This thesis presents the results of a numerical investigation of the whole range, large deflection behaviour of axially and rotationally restrained RC beams and interactions between beams and columns in RC frame structures exposed to fire. The dynamic explicit time integration algorithm implemented in the general finite element package ABAQUS/Explicit solver was used so as to overcome various modelling challenges including temporary instability, local failure of materials, non-convergence and long simulation time. Either load factoring or mass scaling may be used to speed up the simulation process. Validity of the proposed simulation model was checked by comparison of simulation results against relevant test results of restrained RC beams at ambient temperature and in fire. The validated ABAQUS/Explicit model was then used to conduct a comprehensive study of the effects of different levels of axial and rotational restraints on the whole range behaviour of RC beams in fire, including combined bending and compression due to restrained thermal expansion, bending failure, transition from compression to tension when catenary action develops and complete fracture of reinforcement at ultimate failure. The numerical results show that different bending failure modes (middle span sagging failure, end hogging failure due to fracture of tensile reinforcement, end hogging failure due to concrete crushing) can occur under different levels of boundary restraints. Furthermore, release of a large amount of energy during the rapid transition phase from compression to tension in a beam prevents formation of a three hinge mechanism in the beam under bending. The numerical results have also revealed that reliable catenary action develops at large deflections following bending failure only if bending failure is governed by compressive failure of concrete at the end supports whereby a continuous tension path in the beam can develop in the top reinforcement. To allow fire engineering practice to take into consideration the complex restrained RC beam behaviour in fire, a simplified calculation method has been developed and validated against the numerical simulation results. The proposed method is based on sectional analysis and meets the requirements of strain compatibility and force equilibrium. The validation study results have shown that the simplified method can satisfactorily predict the various key quantities of restrained beam axial force and beam deflection-fire exposure time relationships, with the simplified method generally giving results on the safe side. The validated explicit finite element model in ABAQUS was also used to investigate structural interactions between beams and columns within an RC frame structure with different fire exposure scenarios. When fire exposure involves beams and columns located in edge bays of a frame, catenary action cannot develop. Also due to thermal expansion of the connected beam, additional bending moments can generate in the columns. Furthermore, very large hogging moments can be induced at the beam end connected to the internal bay. It is necessary to include these bending moments when designing beams and columns under such fire conditions. Catenary action can develop in interior beams of the frame when fire exposure is in interior bays where the beams have high degrees of axial restraint.

Structures in high seismic risk areas may be susceptible to severe damage in a major earthquake. Structures designed to meet older code requirements may be at even greater risk. When these structures are evaluated with respect to current code criteria, it is observed that they lack of lateral strength and/or ductility. Since safety and economic considerations are major problems, these structures become viable candidates for retrofit and seismic strengthening. For the variety of structures and possible deficiencies that arise, several retrofitting techniques can be considered. Diagonal bracing system is one of the retrofitting techniques and it provides an excellent approach for strengthening and stiffening existing building for lateral forces. Also, another potential advantage of this system is the comparatively small increase in mass associated with the retrofitting scheme since this is a great problem for several retrofitting techniques. In this study, the use of steel bracing for the strengthening of low, intermediate, and relatively high rise reinforced concrete frames are investigated analytically. The ultimate lateral load capacities of the strengthened frames are determined by a load controlled push-over analysis. The post-tensioning effect of preloading is also investigated.

Non-ductile reinforced concrete frame buildings constitute an important part of the vulnerable buildings in seismic regions of the world. Collapse of non-ductile multi story concrete buildings during strong earthquakes in the past resulted in severe casualties and economic losses. Their rehabilitation through retrofitting is a critical issue in reducing seismic risks worldwide. A displacement-based retrofitting approach is presented in this study for seismic retrofitting of medium height non-ductile concrete frames. A minimum amount of shear walls are added for maintaining the deformation levels below the critical level dictated by the existing columns in the critical story, which is usually at the ground story. Detailing of shear walls are based on conforming to the reduced deformation demands of the retrofitted frame/wall system. Member-end rotations are employed as the response parameters for performance evaluation. Initial results obtained from the proposed displacement based approach have revealed that jacketing of columns and confining the end regions of added shear walls are usually unnecessary compared to the conventional force-based approach, where excessive force and deformation capacities are provided regardless of the actual deformation demands.

Many intra-tectonic plate regions are considered to have low to moderate seismic risk. However, devastating earthquakes can occur in these regions and result in high consequences in terms of casualties and damage. Non-ductile detailing practice employed in these structures make them prone to potential damage and failure during an earthquake. Furthermore, the use of infill walls is a divisive issue as on positive side dual wall-frame systems have beneficial effects related to strength, stiffness, and ductility. However, if not designed properly infill wall can also lead to undesirable structural failures of complete wall frame system. Although, there has been significant amount of international research in this area, it is worth noting that very little research exists for Australian frames. This thesis presents the experimental and analytical research conducted at The University of Adelaide to gain some insight into the behaviour of typically detailed Australian reinforced concrete frames subjected to ground motions. The main objectives of this research were (1) to investigate the behaviour of non-seismically designed reinforced concrete frames under a 500-YRP earthquake; (2) to determine the different magnitudes of earthquake (YRP) that are likely to cause excessive drifts in or collapse of gravity-load-designed reinforced concrete frames and (3) to investigate the effect of infill walls on the moment-resisting frames subjected to seismic loads. The experimental program consisted of earthquake simulation tests on a 1/5 scale model of a 3-storey reinforced concrete frame and four ½-scale reinforced concrete brick infilled frame specimens subjected to quasi-static cyclic loading. The analytical study included static pushover and non-linear dynamic analyses of the 3-, 5- and 12-storey reinforced concrete frames. From the overall performance of gravity-load-designed bare reinforced concrete frames considered in this study, it was concluded that the non-seismically designed frames appear to be capable of resisting a “design magnitude earthquake” (i.e., 500- YRP) in low earthquake hazard regions. However, their behaviour under more severe earthquakes (e.g. a 2500-YRP earthquake) is questionable. Perhaps the earthquake design requirements should consider as an alternative the ‘collapse prevention’ limit state for longer return period earthquakes, of the order of 2000–2500-YRP. The experimental research on reinforced concrete infilled frame indicated that the infill wall does not adversely effect the in plane ultimate strength, stiffness, and ductility of the bare reinforced concrete frame. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1372229 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2009

Seismic isolation systems are widely used to protect reinforced concrete (RC) structures against the effects of strong ground motions. After a magnitude 6.6 earthquake, the outpatient building of Lushan People’s hospital in China remained in good condition due to the seismic isolation technology, while the non-isolated older outpatient building nearby experienced major damage. The building provides a good opportunity to study and assess the contribution of isolation systems to seismic performance of RC structures. In the current research project, the isolated outpatient building was modelled and analyzed using computer software SAP2000. The post-yield behaviour of the structure was modelled by assigning multi-linear plastic links to frame objects. The rubber isolators were represented by rubber isolator link elements, assigned as a single joint element between the ground and the superstructure. The isolated structure was subjected to four earthquake records with increasing intensity. The performances of the isolated structure were compared with those of the fixed-base structures in terms of lateral inter-storey drifts, peak absolute floor accelerations, and residual drifts. The laminated rubber bearings, the high damping isolation devices, composed of rubber bearings and viscous dampers, and the hybrid isolation system of rubber bearings and friction pendulum bearings were analysed. The effectiveness of the three base isolation systems considered in enhancing structural performance was investigated. The results show the level of improvement attained in seismic response by each system. They also illustrate that the rubber bearings coupled with friction pendulum bearings produce the best drift control without causing excessive horizontal displacements at the base level and without adversely affecting floor accelerations.

The aim of this work is a static analysis of the reinforced concrete frame structure loaded by the effects of seismic loading. The work deals with the solution of multi-storey reinforced concrete structure designed for common loading conditions and further for possibilities of strengthening of the structure on effect of seismic loading. In the first phase of the work, the static analysis and the design of the main load-bearing elements of the frame structure (columns and main girder) were carried out for the ultimate limit state for the standard design load. In the second phase, the static analysis of the structure for the effects of accidental actions from low and high seismicity was performed and it was assessed whether the main load-bearing elements of the structure would continue to comply. Given that the structure did not satisfy the accidental actions of seismic loading, various ways of structure strengthening were designed and analyzed for their impact on the global and local behaviour of the structure. Also the designing of additional steps for structural reliability were performed. Static analyzes were performed in Scia Engineering and RFEM Dlubal software.

This diploma thesis is processed in the form of design documentation for implementation of building. Solved building is a library in Veselí nad Moravou, cadastre unit Veselí-Předměstí. Building includes three above-ground floors and one underground floor. Floor plan is in shape of rectangular. Beside regular departments of library, study rooms, conference room and office parts, there is also a cafe and a bookstore. The structural system of a building is designed from cast-in-place concrete frame with filling from ceramic blocks Porotherm 30 Profi. Horizontal structural system is from cast-in-place reinforced concrete point-supported slabs. Part of facade is from glass and part is with contact thermal insulation system with mineral wool insulation. Roof construction is designed as flat green roof.