The inherent vulnerability of beam-column joints to seismic loading and steel congestion are two major research problems connected with beam-column joints of moment-resisting frames. The experimental ...study presented herein addresses these research questions and seeks to solve them by using Polyvinyl Alcohol based Engineered Cementitious Composite (PVA-ECC) in beam-column joints without transverse shear reinforcement. The study included the manufacture and shake table testing of two 1:3 reduced scale one bay two-story moment-resisting frame models using simulated earthquake motions. To evaluate the performance of ECC beam-column joints without shear reinforcement, two frame models, one with and the other without shear reinforcement in the beam-column joints, were prepared and tested. The acceleration time history record of the 1994 Northridge Earthquake USA was used for the excitation of specimens at different levels to produce progressive damage up to the near collapse state. The observed damage mechanism of tested models was recorded, and the response parameters, including floor displacement and acceleration, were measured. The measured data was processed to develop a lateral force-displacement envelope curve for the supposed prototype frames and calculate their seismic design factors (ductility, overstrength, and response modification). Comparison of the seismic performance parameters of the two prototype frames reveal that the ECC beam/column joint without shear ties performed marginally inferior to the ECC beam-column joints having shear ties but it still achieved a 75% larger R-factor compared with the code specified value.
•A new component strength deterioration model for stiffened infill plate.•Collapse performance of stiffened steel plate shear wall using FEMA P695 methodology.•Incremental dynamic analysis of ...stiffened steel plate shear walls.•Estimation of seismic response modification factors for stiffened steel plate shear wall.
Unlike unstiffened steel plate shear walls (SPSWs), very little research has been conducted to assess the seismic performance of stiffened SPSWs. This paper presents a new component strength deterioration model for stiffened infill plate to evaluate the seismic performance of stiffened SPSWs using FEMA P695 procedure. The newly developed component strength deterioration model is first validated against the available experimental results. A total of three multi-storey (7-, 10-, and 13-storey) stiffened SPSWs with panel aspect ratio of 1.39 are then analysed using the proposed component strength deterioration model. Static pushover and incremental dynamic analyses using a suite of 44 ground motions compatible to Western Canada are conducted for all archetypes. Adjusted collapse margin ratios obtained for stiffened SPSWs designed with similar response parameters of those for unstiffened SPSWs are compared with allowable limits given in FEMA P695. The results indicate that currently recommended seismic response modification factor, ductility related force modification factor and overstrength related force modification factor, for unstiffened SPSW can be used for design of stiffened SPSW. In addition, seismic response parameters such as variation of maximum interstorey drift and shear demand in different components of stiffened SPSW, boundary columns and infill plates, are estimated in all stories for all designed archetypes during incremental dynamic analysis. Furthermore, seismic response sensitivity of stiffened SPSWs to the variation of post-yielding parameters (i.e., ductility capacity and post-cap stiffness ratio) in infill plate is investigated. Sensitivity analysis shows that the capacity of stiffened SPSW is more sensitive to ductility capacity changes, while the variation of post-cap stiffness has a lesser effect on overall performance of the system.
In this study, the distributions of seismic response parameters and engineering site classes were quantified using a large database of borehole and standard penetration test (SPT) data for the North ...Gyeongsang Province, Korea. Empirical shear wave velocity (VS) profiles were constructed for 17,180 boreholes by applying a series of development methodologies based on combining the SPT–N value (blow count) and the boring log. N–VS relationship for each stratum was used and representative VS values were assigned for the lower rock layer without N value. If necessary, extrapolation and estimation were additionally applied to obtain the mean VS up to a depth of 30 m (VS,30). Seismic response parameters, such as VS,30 and the mean VS of soils above the engineering bedrock (VS,Soil), were derived and analyzed based on the empirical VS profile. Engineering site classification was performed using international and Korean seismic design codes. The validity of the empirical VS acquisition methodology and the related engineering bedrock depth determination were examined by comparing the derived bedrock depth to the appearance ratio and depth of the rock layer in the boring log. The effects of limiting the maximum converted N value, which is applied to the N–VS relationship, and of defining the engineering bedrock as a stratum with VS > 760 m/s were analyzed. Finally, the spatial bias of the borehole locations was reviewed by analyzing the distribution characteristics of the borehole elevations using a digital elevation model. The results may be used as basic data to assess the adequacy of site classification systems, to derive randomized input parameters, and as reference data for international geospatial zonation verification.
This article presents experimental study performed on a first-of-its-kind frame fabricated using crumb rubber concrete, that is, concrete with waste rubbers (crumb) as a partial replacement of fine ...aggregate (sand). A 20% volume of sand was replaced by rubber crumb. Free vibration and shake-table tests were performed on 1:3 reduced scale frame models, both conventional reinforced concrete frame and crumb rubber concrete frame. The dynamic properties (i.e. frequency/time period, elastic viscous damping, and floor acceleration amplification) and seismic response parameters (i.e. ductility and response modification factors) were obtained. In addition, lateral displacement demand was correlated with peak base acceleration to derive seismic response curves. The seismic performance of crumb rubber concrete frame was compared with the conventional reinforced concrete frame in order to assess the feasibility of rubberized concrete for building constructions in areas of active seismicity. The following were concluded on the basis of experimental study: the elastic damping reduced by 12%, the initial time period increased by 6%, specific weight of concrete reduced by 6%, maximum lateral load reduced by 20%, lateral maximum story drift capacity increased by 30%, displacement ductility ratio increased by 2%, response modification factor reduced by 24%, maximum peak base acceleration resistance corresponding the incipient collapse state increased by 40%.
Applying analysis techniques developed for naturally occurring earthquakes to mine seismicity is common practice; however, these methodologies rarely consider the influence of blasting on the dynamic ...rock mass failure processes observed in mines. Due to the complex nature of bulk orebody extraction at depth, quantifying discrete seismic responses to mining can be challenging. This paper identifies seismic responses to mining by pairing single-link clustering with finite temporal windows bound by mine blasting practices. A methodology is presented to quantify the space−time characteristics of these responses using four seismic response parameters (SRPs): distance to blast, distance to centroid, time after blast, and time between events. Using SRPs, seismic responses to mining can be quantitatively classified as induced, complex, or triggered (with respect to discrete mine blasting). Because these response parameters do not require an extensive and (or) triaxial dense sensor array, they are applicable to a variety of underground mining operations. In this work, SRPs are applied to 189 discrete seismic responses occurring over 2 months of active mining, and a 2 week shutdown period, at Agnico Eagle’s LaRonde Mine.
A modified version of a seismic risk assessment method is presented that generalises original risk analytical processes, constructs interrelationships among hazard variables in pre-assign ...weight-based formats, and establishes priorities to address potentially vulnerable dams. The concerned parameter values contained in each component are labelled based on adjusted grading standards, respecting the regional difference in hydraulic structure attributes and safety acceptability ranges. The cascade dams in Dadu River, China, are selected to test the applicability of the proposed method. We systematically investigate potential seismic hazards to demonstrate the implications of earthquake on dam safety. The results indicate that the adapted parameter ranges correspond with the physical aspects of the dams and potential social-economic consequences in seismic-prone regions. Correspondingly, the hazard recognition levels accommodate their local near-source earthquake conditions. Moreover, the investigation guides local emergency services with warnings of potential dam damages and ensuing floods when encountering critical earthquake shaking.
Abstract
Now, every day tall constructing structures constructed around the goal of residential and industrial cause etc. Layout of tall buildings both earthquake as well as wind loads got to be take ...into considered. An irregular structure, failure of structure starts at a point of its weakness and those weaknesses comesups withs separation of mass, stiffness and geometry of that models. The structures having this kinds of discontinuity are called Irregular structures. (H, J, & darshan, 2017) 2. For example,Structures with the soft storey were the foremost remarkable fallen structures. Therefore, the impact of vertical alignment within the seismic structure of buildings is very significant. The changes in durability and size provide powerful features of those structures that are completely different from the standard structure. For this present evaluation ‘ETABS’ software package is employed. All Reinforced Concrete structural elements are follows as per ‘IS 456:2000 (Plane and Reinforce Concrete-Code of Practice, Bureau of Indian Standard)’. Seismic load follows with respect to IS 1893:2016 along with self-weight of modelles for analysis of the structure. Here 2 kinds of buildings of (G+15) were created one is regular structure and alternative one Mass irregular. To observe, Effect of lateral in both buildings using Seismic load and to check the results,most of maximum displacement for various models and various parameters.
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