We are equally aware of how a series of earthquakes that occurred this past influence our lives. Casualties, buildings collapsed, the wheels of government disrupted, economies slowed and many other effects. But if we are wise enough to take lessons from this incident? This paper will review lessons learned from building damage due to failure to apply the concept of earthquake-safe buildings.
Previously, we often hear about the earthquake resistant buildings. Later, the term was changed to a safe house or a home friendly quake quake. In fact, there is no earthquake-resistant houses. The possibility of damage still exists, at least minor damage. However, it is still safe for the occupants, so-called safe houses earthquake.
Earthquake safe buildings built according to minimum standards set by the experts and set forth in the regulations of the earthquake (SNI-2002). If there is a small earthquake, earthquake safe buildings will not be damaged at all, both non-structural components (architectural components) such as walls, ceilings, roofs, doors and windows, as well as structural components (component supporting buildings) such as foundations, pillars, beams, sloof , and the horses.
In the event of an earthquake with a medium-size, the building can be damaged, but only non-structural components only, while the components of the structure is still safe. Meanwhile, when the big quake, buildings may be damaged both non-structural and structural, but should not collapse because it can kill the occupants. For that, the pole or column must be stronger than the beam (in layman’s terms is called Sloof) so that the seismic energy will be absorbed by the first beam damage and is expected after the earthquake ended its pillar is intact or not broken.
This concept will work if the following three things be fulfilled, namely: 1) the size of the building components according to minimum requirements, 2) all building elements are connected properly, and 3) development carried out with strict quality control.
Size of building components is very important because it is associated with the ability to bear the burden of the earthquake that occurred. Size is obtained after analyzing the structure of the principle to equate the burden of working with building components capability to bear. For a simple one-story brick house, the minimum requirements a few components are as follows: pole size 12×12 cm, beam / Sloof 12×20 cm, the size iron at least 4 pieces lengthwise diameter of 10 mm, and iron binding (begol) 8mm diameter with a distance of 15 cm with the tip bent 135o.
The size of the foundation is determined by soil conditions. The more ugly the ground (as in swampy areas or heap), then increasingly in the foundation. The average for a simple one-story house, the depth of the foundation stone of approximately 80 cm. As for wood houses, timber size of the primary structure of the average 8/12cm and 6 / 12 cm, adjusted to the distance of exposition. Meanwhile, for multistory buildings, the size of the building must be calculated by the expert structure in order to have the appropriate size.
In addition, the joints between the building component is also important. In buildings that were damaged or collapsed, often seen the release of relationships between components, such as between the foundation with a pole, the pole with the beams, pillars with walls, pillars with horses, and others. For that, the connection must be interconnected so that if there are earthquakes are not easily separated. There should be cutting or anchor-anchor of iron as a hook between components, such as between the foundation pile, pile with walls, beams with a wall, or pole with the horses. For connection with the beam or column switching between iron, overlapping or overalls should be made so that there is a smooth load distribution. For simple building society house, iron length distribution of at least 40 d (d = diameter of reinforcement) or 40 cm to 10 mm diameter reinforcement. Meanwhile, for timber construction, distribution is done by adding scores on each connection.
The quality of building earthquake-safe is also determined by the quality of material used. For the house walls, quality of materials that must be controlled is the mixing of concrete, steel, brick, mortar (plaster), and wood. Concrete mixture is good for simple home is a ratio of 1 cement, 2 sand, and 3 gravels. Then stir until cook with enough water (1 / 2 part). Water is to determine the strength of concrete. The more water, the lower the quality of concrete. Iron is used also should be a standard SNI (Indonesian National Standard) because it was following the quality test. Do not use iron without SNI.
Bricks need to be tested simply by trample brick placed on two runways. If not broken, then the quality is good. Once the importance of the test, until there is a joke in circulation, there is an endurance test by brick struck the forehead. According to joke that, if broken bricks, it means quality is not good, otherwise if a bloody forehead, good quality.
Before installed, the brick should be soaked in water beforehand. For mortar, the quality is good is 1 cement and 4 sand. As for the wood, use dry wood and the wood is not much currency. Use a preservative, for durable wood.
All three of the above if done right, God willing, the building will be safe tergadap earthquake. Indeed the cost of this earthquake safe buildings more expensive for about 30% of the ordinary buildings, but the value does not mean anything compared to the value of our comfort during inhabit the building.
Tags: building concept, earthquake safe