Recognizing Foundations as Sub Building Structure

Recognizing Foundations as Sub Building Structure

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Recognizing Foundations as Sub Building Structure

All building construction is designed to be built on the ground and must be supported by a foundation. the foundation is part of an engineering system that continues the load supported by the foundation and its own weight to and into the soil with rocks located below it. The resulting ground voltages except on the ground surface, are in addition to the burdens that already exist in the soil mass from the weight of the material itself and its geological history. The cumulative expenses of the floor and buildings above it (super structure) are received by the foundation (substructure) which deals directly with the land.

The function of the foundation is to safely forward a centralized reaction from the column and / or wall or lateral loads from the retaining wall, to the ground, without the occurrence of differential settlements in the structural system without the collapse of the soil. Conditioning structure buildings depends entirely on the local soil structure.

Land must be able to support and sustain the burden of any construction planned on the land without the occurrence of shear failure and the resulting deflection deflection can be surveyed for the construction. A foundation for building a structure must be sufficient so that the construction has satisfactory use and to be safely occupied. A foundation must be able to meet several stability requirements and deformation requirements such as:

1. The depth must be able to anticipate the expenditure or shift of material / soil in the lateral direction from the bottom of the foundation, especially for the palm and raft foundations.
2. Depth must be below the area of ​​seasonal volume changes caused by freezing, disbursement and project growth.
3. The system must be safe against reversal, rotation. pushing or broken ground (shear strength failure).
4. The system must be safe against corrosion or deterioration caused by hazardous materials found in the soil. This needs special attention when returning to stockpile with good landfill, especially for marine-related foundations.
5. The system must be sufficient to withstand some changes in place or geometric construction.
6. The foundation must be economical in the installation method.
7. The whole movement (generally deflections) and differential movements must be able to be traced to both the foundation elements and the elements of the building above the ground.
8. The foundation and construction must meet the standard requirements for environmental protection.

If the foundation is incorrectly designed, then there will be a part of the structure that has a greater decline than the surrounding area. Various structural elements that meet at the convergence point of the columns will experience more stress due to the unequal decline, which in the end will result in excessive deformation.

Additional bending and torsional moments that exceed the resistive capacity of structural elements can result in excessive cracking due to the melting of the reinforcement, and eventually lead to collapse.

If the entire structure experiences a uniform decrease, only a small or no excess voltage will occur. Such behavior can be studied on very rigid foundations and the soil is so soft that the above structure behaves like a floating object, which can change position without damage.

Examples of such structures can be seen, such as in Mexico City, whose buildings have shallow foundations and have experienced a few feet of decline over the years as a result of the land consolidation process.

Other examples of very slow declines, or also the consolidation process is not uniform, also the gradual loss of structural stability, as happened in the Pisa italy skewed tower, is an example of a non-uniform foundation reduction problem.

The layout plan of a structure is very diverse, as well as the soil conditions can differ in an area and in other areas far apart and nearby. As a result, the type of foundation chosen must be based on these factors, plus other factors, such as economic factors.

In summary, the structural planner must obtain complete land data as needed before determining the type and layout of the foundation of a planned structure. Therefore, it is highly recommended and recommended to have basic knowledge about soil mechanics and foundation techniques before planning a foundation.

To be able to determine the amount of bearing capacity for a particular area and determine the foundation system to be used, basic knowledge is needed regarding the determination of cohesive and non-cohesive soil resistance. Data needed to find out The carrying capacity of the soil is usually determined by drilling the soil or by investigating other land.

History and color meaning of Helmet Safety

History and color meaning of Helmet Safety

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History and color meaning of Helmet Safety

The use of safety helmets (Safety Helmet) starts from workers in a dock or shipyard. Before safety helmets or safety helmets are created they usually protect their heads using hardened dry asphalt which is dried in the sun. The purpose of this use is to cover and protect their heads from the threat of falling or falling objects on the deck of the ship they are building. Officially the first safety helmet was developed in 1912 at the Royal Worker’s Accident Insurance Institute in Bohemia.

In addition to the history of Safety helmets, the basic ingredients for making safety helmets also change along with the development of new and more effective material technologies. The following are the basic ingredients for making helmet safety from time to time:

1. Asphalt was dried before 1912
2. Thick canvas in 1919
3. Aluminum in 1938 (this material should not be used in electricity workers because it is dangerous and can be electrocuted)
4. Fiberglass in 1940
5. Thermoplastic in 1950
6. High Density Polyethylene or HDPE which is still used today.

Safety helmets are of two types, namely:

1. Safety helmet underground or tunnel mining workers. This helmet is in the shape of a wide edge and above is more prominent with a hanger or place for placing a flashlight.
2. Safety helmets used in mining areas or open industries. This helmet is just ordinary or more general.

The Meaning and Purpose of Helmet Safety Colors

The colors on the safety helmet are very striking and bright like yellow, white, orange, green, blue, red etc. The main purpose of the color of the safety helmet is that workers who use this safety helmet will be more easily seen if there are vehicles or heavy equipment that will pass so they are not hit.

But now safety helmets have their own color meaning. The following are some colors of safety helmets that reflect a person's position or position.

1. White safety helmets are usually used by managers, supervisors, engineers, and foremen.
2. Blue safety helmets are usually used by site supervisors, electrical, contractors or temporary supervisors.
3. Yellow safety helmet is usually used by sub contractors or general workers.
4. Green safety helmets are usually used by environmental inspectors.
5. Pink safety helmets are usually worn by new workers or interns.
6. Orange safety helmets are usually worn by company guests.
7. Red safety helmet is usually used by the safety officer who is responsible for checking the safety system that has been installed and functioning in accordance with the standards set.

Actually this safety helmet color difference classification is not yet clear. Maybe this applies after many people interpret and define it so that it becomes a tradition.

Usually the safety helmet color classification is different or not applicable in every country even on every site or project. For example, workers in oil mining, people who use yellow safety helmets are the Operation Department division which is considered the most important unit and consists of skilled Engineers. So for them, yellow hats are the highest status or class, while in yellow construction hats, the lowest class is general workers including cleaner.

Main Functions of Helmet Safety

1. The main function of using a safety helmet is to protect the head to avoid falling goods and others.
2. In using safety helmets there are several things that must be considered including:
3. Before being used, examine that the helmet is in good condition to use, fit and comfortable in the head (not loose and not too narrow), not damaged and deformed.
4. Use a safety helmet in the head properly (not tilted, not looking up, or looking down so that it covers the view or upside down).
5. If you are in a high place and windy conditions, chain strips or chin straps should be used to avoid flying safety helmets due to high winds.

The use of a safety helmet usually has a usage limit, the average age of use of a safety helmet is five years, but this is very dependent on the material used to make the helmet. If the use of a safety helmet is damaged such as being hit by a falling object or being hit by a collision, the helmet must be replaced as soon as possible with a new one. Do not use a safety helmet that has been damaged or damaged.

Every manufacturer of a safety helmet will state the maximum usage limit for the helmet. Check carefully. It should also be noted that the helmet that is finished is cleaned every day. This is done to avoid damage to the material due to sticking dirt. Because it could be dirt is a chemical or oil that can trigger damage to the base material on the safety helmet.

Who is the founder of the Chicken Claw Building Foundation - Prof. Dr. (HC) Ir. R. M. Sedyatmo

Who is the founder of the Chicken Claw Building Foundation - Prof. Dr. (HC) Ir. R. M. Sedyatmo

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Who is the founder of the Chicken Claw Building Foundation - Prof. Dr. (HC) Ir. R. M. Sedyatmo

Prof. Dr. (HC) Ir. R. M. Sedyatmo is one of the leaders of Indonesian Civil Engineers, scholars, practitioners, scientists and professors of the Bandung Institute of Technology. He was born in Karanganyar, Central Java in 1909. He went through basic education at HIS Solo (1916-1923), continued to MULO Solo (1923-1927), and AMS B in Yogyakarta (1927-1930). Sedyatmo is often nicknamed "The Kancil" because it is famous for its many intellect. He studied at the Bandoeng Te Technicche Hoogeschool (THS) now ITB Bandung (1930-1934). After graduating from THS in 1934 with a four-year study period, Sedyatmo worked as a planning engineer in various government agencies.

Career

His career in the academic world began on October 1, 1950 with his appointment as an extraordinary lecturer for vak Waterkracht (the field of hydropower) in the Civil Engineering Faculty of Engineering, University of Indonesia Bandung (ITB). On August 1, 1951 he was officially appointed as extraordinary professor in the field of hydropower. He is the second native professor in ITB's civil department after Prof. Ir. Roosseno. At the third Lustrum (15th Anniversary) Bandung Institute of Technology on March 2, 1974 Sedyatmo received an honor in the form of Doctor Honoris Causa in Engineering from the ITB Senate, on the basis of an assessment of his services as an engineer, with promoter Prof. Ir. Soetedjo.

History

Prof. Dr. Ir. Sedyatmo in 1961 when PLN officials had to establish seven high voltage power towers in the Ancol swamp area of ​​Jakarta. With difficulty, the two towers were successfully established with a conventional foundation system, while the remaining five towers were still abandoned. The tower delivers electricity and an electric power center at Tanjung Priok to the Senayan Sports Center where the 1962 Asian Games sports party will be held.

Because the time is very urgent, while the conventional foundation system is very difficult to implement in the swamps, a new system is sought. The idea of ​​Ir. Sedyatmo to erect a tower on a foundation consisting of concrete plates supported by concrete pipes below it. The pipes and plates are monolithically attached, and gripping the ground softly.

By sedyatmo, the findings were named chicken paw foundation systems. The tower can be completed on time, and remains firmly established in the Ancol area which is now an industrial area. For areas with soft soil, chicken claw foundations are not only suitable for building buildings, but also for making roads and runways. One more advantage, this system does not require a drainage system and receding connections.

Structure

The foundation of chicken claws consists of relatively thin reinforced concrete plates supported by buis-buis reinforced concrete mounted vertically and monolithically combined with concrete plates at a distance of 200-250 cm. The thickness of the concrete plate ranges from 10-20 cm, while reinforced concrete pipes are 120 cm in diameter, 8 cm thick and range from 150-250 cm. Buis - buis concrete is useful for plate stiffeners. In supporting the building load, buis-concrete plate and confined soil in the foundation work together, thus creating a composite system which in its overall way of operation will be identical to the foundation raft foundation.

The mechanism of the chicken claw foundation system in carrying the burden of the observations is as follows:

If above the plate the point load works, the load makes the plate fade. This deflection causes buis - buis rotating chicken claws. Observations on the model show the rotation of the chicken claw mobilizing lateral soil pressure behind the chicken's claw and is a moment against plate deflection. Thus, how to reduce deflection, the greater the moment against the chicken's claw to fight deflection, the greater the deflection reduction. The opposing claw moment is affected by claw dimensions and soil density conditions (shear strength) around the claw, ie the longer and also the width of the claw, the greater the opponent's moment against the plate deflection that can be obtained.

Many buildings have used Prof.'s chicken claw foundation system. Sedyatmo, including hundreds of high voltage PLN towers, aircraft hangars with a stretch of 64 m in Jakarta and Surabaya, between runway and taxi way and apron at Soekarno Hatta Airport in Jakarta, Pluit access road - Cengkareng, fertilizer factories in Surabaya, swimming pools and tribune in Samarinda, Palembang - Indralaya toll road, and hundreds of high-rise buildings in various cities.

The chicken claw foundation system has also been widely known in various countries, and has even received international patent recognition in 40 countries, namely: Indonesia, Malaysia, Singapore, Thailand, Philippines, Vietnam, India, China, Japan, South Korea, Mexico, Saudi Arabia, Bahrain , Sri Lanka, Brazil, Qatar, Soviet Union, Burma, Egypt, South Africa, Portugal, Spain, Argentina, Chile, Australia, Brunei Darussalam, New Zealand, Morocco, West Germany, East Germany, England, Italy, Belgium, Canada, America United, Netherlands and Denmark.

4 Factors affecting the strength of concrete

4 Factors affecting the strength of concrete

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In construction, concrete is a composite building material made from a combination of aggregate and cement binder. The most common form of concrete is Portland cement concrete, which consists of mineral aggregates (usually gravel and sand), cement and water. In the world of construction, concrete has a vital role. Concrete construction is the building structure of a building. The strength of concrete construction is the backbone of the building or not. Then what are the concrete compilers themselves and what factors affect their strength?

The following is an explanation of the factors that influence the strength of a concrete structure.

1. Cement content

The more cement material you will use, the stronger and better reinforced concrete construction will be produced. The use of cement is directly proportional to the strength of concrete construction.

2. Water Content

The more water you use, the worse the construction of the concrete. Although in the construction of lightweight concrete construction, if water is used a lot, the construction of concrete is easier to do and the work becomes lighter. The key is to use as little water as possible, just so that a mixture of concrete construction can be done (can be transported, casted, compacted and finished).

3. Water Mixture and Cement Material or Cement Air Fakor

The higher the ratio of the mixture of water and cement materials, the concrete construction will be even worse. To improve the quality of concrete construction, the house must reduce the ratio of water and cement materials.

The water and cement material is the ratio between the weight of water compared to the weight of cement material. If we symbolize water with W, and we symbolize the cement material with C then the formula is FAS = W / C, where the density of water is 1 kg / liter, and the density of cement material is 3150 kg / m3 (required American Standard Testing and Material).

4. Aggregate (Sand and coral)

A mixture that is too much sand even though it will make the concrete smooth but its strength is slightly reduced, when compared to a normal mixture. The strength of the concrete will decrease if the mixing uses molen for too long. Conversely, if concrete consists of a lot of coral, concrete construction will be rough but its strength becomes better when compared to concrete that uses more sand.