In an earthquake (seismic waves), a frame with suitable properties and data can develop plastic hinges that will absorb energy and allow the frame to withstand actual displacements that are larger than calculated in an elastic-based design concepts. In modern moment frames, the ends of beams and columns, being the locations of max seismic moment, are designed to sustain inelastic behavior associated with plastic hinging over many cycles and load reversals. Frames that are designed and detailed for the ductile behavior are called “special” moment frames. Frames without special seismic detailing depend on the reserve strength inherent in the design of the members. The basis of this reserve strength is the load factors in the safety under working-stress design methods.
The study of behavior of RC beam column joints under seismic loading and endeavors for predicting the joint shear strength has started long back [Hanson and Connor, 1967 as reported by Park and Pauley, 1975], however, the collapse of many RC buildings in recent past earthquakes has been attributed to failure of beam-column joints. The prediction of accurate joint shear strength is difficult task since it depends on complex interactions of various parameters. Many researchers have proposed analytical models for predicting joint shear strength; however, theses analytical models are generally based on limited set of experimental results. From the literature, the crucial parameters affecting the joint shear strength have been identified as beam
Such a framework makes the skyscraper strong enough and yet flexible enough to withstand an earthquake. Earthquake-resistant homes, schools, and workplaces have heavy appliances, furniture, and other structures fastened down to prevent them from toppling when the building shakes. Gas and water lines must be specially reinforced with flexible joints to prevent breaking. 9.5 Building Drift 9.5.1 Building Drift Caused by Lateral
Nonetheless, if they are provided along only one direction, to resist strong earthquake effects in the vertical plane, a proper grid of beams and columns must be provided along the other direction. To reduce ill-effects of twist in buildings, shear wall must be symmetrically located in plan of the building. They could be placed symmetrically along one or both directions in plan. The most effective way of placing a shear wall is when it is located along exterior perimeter of the building – such a formation increases resistance of the building to twisting. A competent wall of this type is both stiff and strong.
For instance, in Imamura et al (2012), the authors produced hazard maps based on a single earthquake event — a sample less representational than one in which several historical earthquakes were included. Estimating a realistic evacuation clearance time depends not only on the results of a hazard analysis, but also on the results of vulnerability and behavioral analyses; both of these, together, provide details of the demographic variables that significantly affect evacuation clearance time (Charnkol and Tanaboriboon, 2006; Post et al,
Avoid superfluous presence of masses, such as excessive fillers on terraces, garden terraces, etc. It is desirable to solve the water supply systems which avoid the construction of a voluminous water reserve the highest level of the building. 188.8.131.52 Density structure in plant In old buildings, there is a large amount of walls with large structural function. It was also found that many of them have worked well for centuries in earthquakes zones taking the gravity and seismic loads to the ground by direct routes. When we have the largest presence of structure on the ground floor the building is better able to withstand the shear force on the ground floor, the upper floors accumulated and accumulated gravity loads.
Pull rod made of 30CrNiMo8 steel in the ATOX grinding mill are used to exert grinding pressure on the rollers. The grinding forces are transmitted vertically by the 3 pull rod which is placed at 1200C apart directly into the hydraulic cylinder. This paper describes the metallurgical investigation that was carried on a failed pull rod to understand the cause of failure. Fracture surface of the failed pull rod showed multiple ratchet mark indicated that the crack was initiated at multiple regions. Higher fatigue zone (55%) with low over load region (45%) indicated that the load was light, but there were high stress concentration zone on the pull rod.
Recent earthquakes in which many concrete structures have been severely damaged or collapsed. About 60% of the land area of our country is susceptible to damaging levels of seismic hazard. We can’t avoid future earthquakes The research concentrates on a computer based push-over analysis technique for performance-based design of reinforced concrete building and steel building works subjected to earthquake loading. In the investigation, nonlinear static analysis of analytical model of four story Reinforced concrete building and steel building is conducted for local seismic conditions. Pushover analysis is an advanced tool to carry out static nonlinear analysis of framed structures.
Seismic waves that originate from a point source are spherical in nature, and when incident on a plane reflector, they sweep through it by producing a succession of contact zones. Nonetheless, the limited planar area, which ‘effectively’ comes into contact at the interface and collectively contributes to produce a coherent reflection, is called the first Fresnel zone (Figure 2.16).The quality of a reflection depends not only on the area defined by Fresnel zone but also on the type of the reflecting surface. The lateral changes in reflectivity of planar widths less than a Fresnel zone tend to deteriorate the reflection quality. Modeling has demonstrated that interfaces having width less than λ/4 cannot be viewed clearly and thus defines the limit for spatial resolution (Niranjan,
Nonlinear static procedures are now widely used in engineering practice to predict seismic demands in building structures. The simplified versions of NSP based on lateral load capacity such as those recommended in ATC-40 and FEMA-356 have well-documented limitations in terms of their inability to account for higher mode effects and modal variation resulting from inelastic behaviour. Results from the analytical study indicate that peak response measures such as inter-story drift and component plastic rotations more consistently than the other NSP’s investigated in the