The Performance of Different Building Types During an Earthquake
The Performance of Different Building Types During an Earthquake During earthquakes, different types of structures sustain varying degrees of damage, which has been investigated here. Adobe and Mud Houses in the Event of an Earthquake Adobe construction is made of unburned sun-dried bricks set in mud mortar. Mud houses are the most traditional and acceptable building for the poor because to their inexpensive initial cost, easy availability, low level of construction expertise, and great insulation against heat and cold. In India, more than 100 million people live in these types of homes.There are numerous examples of complete collapse of such buildings in 1906 Assam, 1948 Ashkhabad, 1960 Agadir, 1966 Tashkent, 1967 Koyna, 1975 Kinnaur, 1979 Indo-Nepal, 1980 Jammu and Kashmir and 1982 Dhamar earthquakes.
It has poor shear, tension, and compression properties. Ground shaking makes it easy for walls to separate at corners and junctions. The cracks are caused by the deterioration of the joints. The entire home collapses when the walls break due to bending or shearing in combination with compressive pressures. During earthquakes, extensive damage has been reported, especially if they occur after rain (Krishna and Chandra, 1983). Mixing the mud with clay to offer the cohesive strength results in better performance. The tensile strength of straw is improved by combining it with it. Weather resistance is improved by coating the outer wall with a waterproof substance such as bitumen. Split bamboo or timber reinforcement can considerably increase the strength of mud walls. Horizontal timber runners or a timber frame.
Earthquake Damage to Masonry Structures
Brick and stone masonry constructions are superior in terms of durability, fire resistance, heat resistance, and formative effects. Masonry structures come in a variety of materials and sizes: (I) Large block (block size greater than 50 cm)-limestones, concrete blocks, or rock blocks (ii) solid and hollow concrete bricks Natural stone masonry (iii).This style of building is commonly employed due to its ease of availability, economic considerations, and the benefits described above. Buildings in the Himalayas are made out of stacks of random rock stones without the use of mortar. Mud mortar is used in the majority of new building, but cement mortar is used in a small percentage of cases. Failures of masonry structures are caused by the following factors: These structures are massive and attract a lot of inertia. Masonry walls that aren’t strengthened are flimsy.
Due to a lack of integrity, these structures have fallen apart and collapsed. Lack of ‘through’ stones, lack of bonding between cross walls, lack of diaphragm action of roofs, and lack of box light action could all contribute to the lack of structural integrity. Damage to masonry structures is common: All of them suffer serious damage, resulting in full collapse and pileup in a heap of stones. The roof or floor’s inertia forces are communicated to the tops of the walls, and if the roofing material is poorly secured to the wall, it will dislodge. The separation of the roof from the support is caused by a weak roof support connection, which leads to catastrophic collapse. The bottom chord of a roof truss may fail.
Buildings during Earthquake
If the roof/floor material is securely fastened to the top walls, it will shear diagonally in the direction of movement through the bedding joints. The cracks normally originate at the edges of the apertures. The combined effect of flexure and shear causes the pier to break. Wall separations are indicated by near vertical cracks around corner wall joints. The bending moment at the ends of motion perpendicular to the walls causes cracking and separation of the walls due to weak bonding. In most cases, the gable end wall collapses. The Wythe of masonry bulges outward or inward due to strong inertia forces acting on the walls.On the bulged side, half of the wall thickness can be seen sliding away.
Random rubble masonry has proved to perform marginally better than unreinforced dressed rubble masonry (DRM). Cracks in the walls are the most typical cause of damage. Masonry with a smaller unit mass and higher bond strength performs better. In seismic areas, unreinforced masonry should be avoided as much as possible as a construction material. Buildings with Reinforced Masonry During Earthquakes Reinforced masonry structures have fared well in earthquakes, sustaining minimal damage. A robust member capable of taking bending is proven to perform better during earthquakes for horizontal bending. Even more strength can be achieved by reinforcing the corner portions or aperture with steel bars. Even a dry-stacked stone masonry wall with a continuous lintel band over apertures and cross walls did not experience any movement.
Buildings with Brick-Reinforced Concrete Frames During an Earthquake
Buildings with Brick-Reinforced Concrete Frames During an Earthquake This sort of structure is made up of RC frame structures with infill bricks laid in cement mortar. In earthquake zones, this form of construction is appropriate.Failures of RC frame structures are caused by a lack of adequate design in the beams/columns, frame action, and foundation. Poor construction quality, with insufficient detailing or reinforcement in various components, especially at joints and in columns/beams for ductility. Roof and floor diaphragm action is insufficient. Inadequate masonry wall treatment. In RC frame structures, the following types of damage are common: The breakdown of infill or columns or beams is the most common cause of damage. Concrete in columns is splintering. Excessive bending causes cracking or buckling.
Shearing action causes a severe crack near the frame’s rigid joints, which can lead to full collapse. Excessive moments in the frame are also caused by differential settling, which can lead to failure. Because beam failure is less harmful than common failure, the frame should be designed so that the plastic hinge is confined to the beam only. Earthquake Damage to Wooden Structures This is also the most popular style of construction in seismically active areas. It’s also the best material for earthquake-resistant construction because of its light weight and shear strength across the grains, as evidenced by the earthquakes in Long Beach in 1933, Kern County in 1952, Skopje in 1963, and Anchorage in 1964. However, after the Tokachi earthquake in 1968, more than 4,000 wooden structures were either destroyed or damaged.
Reinforced Concrete Buildings during Earthquakes
In addition, because to the weakness of the ground, there were failures due to sliding and caving in. Its low stiffness joints, which act as a hinge, were the main cause of failure. The failure can also be attributed to the decay of wood over time. Without walls, wood frames are almost impervious to horizontal stresses. The diagonally braced wall has the maximum resistance. The performance of buildings with diagonal bracing in both the vertical and horizontal planes is significantly improved. During earthquakes, Assam’s traditional wood frame Ikra building and Nicobar houses built on wooden piles isolated from the ground have performed admirably. Up to two storeys, wood homes are often adequate.
Vibrational failure and tilting or uneven settlement are two types of damage to reinforced concrete structures. When a reinforced concrete building is built on relatively hard ground, it experiences vibratory failure, but on soft ground, it experiences tilting, uneven settlement, or sinking. The reasons of damage in cases of vibratory failure may vary, but in general, the seismic forces acting on a building during an earthquake exceeded the loads considered in the design, and the buildings lacked the necessary resistance and ductility to handle them. As seen in the earthquakes in Skopje (1963) and Kern Country (1952), these structures performed admirably.
Because shorter buildings are stiffer than taller ones, a three-story apartment house.
Some of the most susceptible structures to shaking damage are soft-story apartments and condominiums.
Ground vibrations during earthquakes cause inertia forces at locations of mass in the building.