Variations among primary beam, secondary beam and tie beam

Primary Beam: Primary beam stands for a horizontal beam that joins columns (simply supported or shear connected) to transmits the load of a structure from secondary beam (when exist) to the columns right away.

Generally, primary beams are found in a regular building structure. The depth of the primary beams remains higher as compared to secondary beams. Primary beam functions as a medium among columns and secondary beams.

Secondary Beam: It belongs to a horizontal beam that joins primary beams (simply supported or shear connected) to transmit the loads of a structure to the primary beam. It is not directly attached to the columns.

The purpose of these beams is to support and minimize the deflection of beams and slabs.

Tie Beam: It belongs to a horizontal beam that joins two rafters in a roof or roof truss to transmit the load of the rafter to the column of the structure as well as tighten the entire building structure.

Normally, it is found in roof truss.

• Tie beam normally binds the columns and foundation at certain level
• Plinth beam at Plinth level
• Ground beam at Existing ground level

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Brief overview of Seismic Design

The mass of the building to be designed manages seismic design apart from the building stiffness, since earthquake produces inertia forces which are proportional to the building mass.

If the buildings are designed to function elastically throughout earthquakes devoid of any damage, the project becomes economically illogical.

Because of this, it is essential for the structure to endure damage and thus disperse the energy input to it throughout the earthquake. So, the conventional earthquake-resistant design philosophy needs that normal buildings should have the capacity to withstand earthquake.

Minor (and regular) shaking with no damage to structural and non-structural elements.

Moderate shaking with small damage to structural components, and some damage to non-structural elements.

Extreme (and unusual) shaking with damage to structural components, but with NO collapse (to save life and property inside/adjacent to the building.

SEISMIC DESIGN FACTORS: The following factors provide a great impact on the building design. Serious attentions should be given in the design phase.

Torsion: Objects and buildings contain a center of mass i.e. a point by which the object (building) is balanced devoid of rotation taking place. If the mass allotted consistently then the geometric center of the floor and the center of mass may meet.

If the mass is allotted unequally, the center of mass is placed outside of the geometric center and it leads to "torsion" producing stress concentrations. A specific amount of torsion is indispensable in each building design. If the masses are organized uniformly, it will lead to balanced stiffness against either direction and maintain torsion within a agreeable range.

Damping: Usually, the buildings are poor resonators to dynamic shock and disperse vibration by engrossing it. The natural vibration is consumed with damping.

Ductility: Ductility is the property of a material (like steel) to bend, flex, or move, but fails due to happening of significant deformation. Non-ductile materials (like weakly reinforced concrete) fail unexpectedly by crumbling. It is possible to attain superior ductility with carefully detailed joints.

Strength and Stiffness: Strength is a property of a material to defy and tolerate applied forces within a safe limit. Stiffness of a material refers to a degree of resistance to deflection or drift (drift being a horizontal story-to-story relative displacement).

Building Configuration: This term defines a building's size and shape, and structural and nonstructural components. Building configuration establishes the way seismic forces are circulated within the structure, their relative magnitude, and problematic design concerns.



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Concept of retaining wall designing

Retaining Wall: If it is required to provide support to an excavated area or a lower area of minimum 1 or 1.2 meters or more from a lifted section of the soil, a retaining wall should be set up there. This type of structure is suitable to withstand the lateral pressure resulting from the soil.

The retaining walls are generally constructed in the basement part of a building structure. While applying as integral to basement walls, they are frequently utilized as a support for floor diaphragm and a return wall that build them too rigid for active soil pressure to form necessary higher design loads and a dissimilar design approach.

The design of retaining wall is based on the following mode of failures:

Retaining Wall Mode of Failures

1. Overturning: The retaining wall under overturning failure easily collapses in bending.

2. Sliding: Retaining wall that collapses because of sliding often contain non-cohesive soils. The walls shift outer with a passive failure of soil ahead of foundation and active failure of soil back the wall. Many times a key is necessary under the foundation to stop sliding.

3. Bearing Check: Bearing check should be done because of the failure when the soil remains under the toe of the foundation and a forward rotation of the wall.

4. Overstress on any part of the Retaining Wall happens because of either bending or shear.

5. General Stability. It is a obstruction on slope failure, overall stability, and base stability.

Concept of forces in Retaining Walls: Exclusive of the self-weight, weight of soil and weight caused by the water it carries, the lateral soil pressure on the walls also requires to take into account.

The allocation of pressure P is similar to the area under the pressure distribution figure, and its line of action moves through the centroid of the pressure. While calculating earth pressure on walls, three common conditions of loading are usually taken into account.

2. Surcharge: A surcharge belongs to a Horizontal surface of fill that bears a uniformly distributed surplus load as a result of an adjoining neighbor or road traffic.

The pressure due to surcharge measured by transiting its load equivalent, an imaginary height of soil h’ over the top of the wall is stated as h=s/ɣ.

To get more detail, go through the following link thestructuralworld.com




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New technology in earthquake engineering to resist collapsing of the structures

It is the big challenge for the structural engineers to develop earthquake resistance structures.

An Earthquake resistant structure should have the capacity to resist abrupt ground shaking to reduce the damages to the structure.

Though the reinforced Concrete contains sound earthquake resistance capacity of buildings but owing to the substandard mix design of concrete and improper curing the reinforced concrete lost it’s desired compressive strength and it leads to collapsing of structure during an earthquakes.

Recently, a new innovation is launched in earthquake engineering where the curtain of cables is affixed to ground to significantly enhance the earthquake resistance strength of the building.

In these technology threads are used which are created with thermoplastic carbon fibre composite. These threads are fastened and knotted to produce a strong flexible rod which is 90% lighter as compared to reinforcement bars and contain the equivalent strength.

To resist earthquake successfully, these composite rods are fastened & secured from the roof to the ground and set up around the building. Rods are also set up inside the building to make the interior walls stronger.

These Composite threads are formed with textiles so that the rods can expand and pull the structure back in opposite direction to withstand shaking of the structure.

When an earthquake occurs, in case the building is pushed towards left side, the threads or rods located on right side pulls it back to retain the building in exact position and significantly reduces the structural damage and human death.

For online demonstration of this new technology, go through the following video tutorial.

Video Source: TomoNews US

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Details of design and construction process of Burj Khalifa

Excavation work began for Burj Khalifa is known as the tallest skyscraper in the world in and it’s excavation work was started in January 2004. It took 1325 days for the completion of the structure.

The superstructure is supported with over 165 stories. The final height of the building is 2,717 feet (828 meters). The 280,000 m2 (3,000,000 ft2) reinforced concrete is used for Dubai tower and employed for retail, a Giorgio Armani Hotel, residential and office.

Structural System Description: 3D Structural Analysis Model of Burj Dubai TowerBurj Khalifa contains "refuge floors" at 25 to 30 story intervals which have great fire resistance capacity as well as individual air supplies to cope up with any emergency situation. With the support of reinforced concrete structure, the building becomes stronger as compared to steel-frame skyscrapers.

Designers intentionally constructed the structural concrete in Burj Dubai as "Y" shaped in plan with the purpose of minimizing the effect of wind forces on the tower along with the intension to retain the structure simple and support constructability. The structural system is defined as a "buttressed" core.

Every section contains its own high performance concrete corridor walls and perimeter columns and supports the others through a six-sided central core, or hexagonal hub. So, a tower is built with enormously rigid lateral and torsion capacity. An inflexible geometry is utilized with the tower that organized all the common central core, wall, and column elements.

Each tier of the building sets back in a spiral stepping pattern up the building. The setbacks are arranged through the Tower's grid, so that the building stepping can be completed by positioning the columns over with walls beneath to set a smooth load path. It facilitates the construction to get rid of the issues resulting from column transfers.

The setbacks are arranged in such way that the Tower's width alters at each setback. The benefit of the stepping and shaping is to "confuse the wind'1. The wind vortices don’t get structured as at each new tier the wind experiences a dissimilar building shape.

Structural Analysis and Design Facts: The center hexagonal reinforced concrete core walls set the torsional resistance of the structure same as a closed tube or axle. The center hexagonal walls are supported with the wing walls and hammer head walls which operate as the webs and flanges of a beam to withstand the wind shears and moments.

Outriggers at the mechanical floors facilitate the columns to contribute to the lateral load resistance of the structure; so, all of the vertical concrete is applied to support both gravity and lateral loads. The wall concrete designated strengths vary from C80 to C60 cube strength and employ Portland cement and fly ash.

To get more information on construction details, go through the following article aboutcivil.org




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Brief overview of Moving Buildings

If the structures are shifted from its original position to new site, the process is known as moving buildings.

Moving buildings is based on the following factors:

• Motivations to move buildings
• Groundwork of structure
• Moving building method
• Types of moving buildings
• Safety measures required for moving of the structure successfully

Motivations to Move Buildings: Due to several reasons, it becomes necessary to shift buildings from its original positions to new locations. As for instance – resist demolishing of historical structures and retain them when their locations are essential for industrial purposes or as a result of increasing in population density, new residential buildings should be developed.

Another reason is that building is not built up as per exact plans and arrangements. Therefore, buildings should have been shifted to make necessary arrangements.

The process for moving building to the new position will be cost-effective as compared to demolish it and then develop new buildings.

In some cases, the residential areas are greatly affected by recurring catastrophic natural events like flooding, so, under this circumstance moving buildings will be the only alternative.

Historical houses are frequently moved and collected to build up a historical village.

Underpinning of Structure: Building underpinning plays an important role in the process of moving buildings and several methods are available through which underpinning of structure is carried out.

The Underpinning methods applied for moving buildings range from underpinning by continuous strip foundation, underpinning with piers or bases, underpinning by piles, pretest methods of underpinning, underpinning by injections, and freezing and thawing underpinning.

Moving Building Process: Generally, underpinning is the most effective method in the process of moving building. But sound knowledge and experience are required to execute such vital operation.

Usually, moving building is accomplished on the basis of sufficient surveying of the structure and calculation of loads properly as well as in-depth investigation and analysis of soils at new site of the building and at tracks on which the building is shifted, and exact jacking along with equalizing measuring strain equipment.

Moving building method comprises of the provision of a system of beams on which the building weight is retained, and these beams are arranged on a roller or wheel carriage that is set on rail track. The rail track is arranged on the ground as per the preferred direction.

To get more details, click on the following link theconstructor.org

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How to make analysis of a 5 storied building with ETABS

This construction video focuses on how to use ETABS for making analysis of a 5 story industrial building.

ETABS provides integrated analysis, design and drafting of building systems. The most updated version is ETABS 2015.This newest ETABS contains supreme 3D object based modeling and visualization tools, brilliantly rapid linear and nonlinear analytical power, elegant and extensive design aptitude for diversified materials, and discerning graphic displays, reports, and schematic drawings etc. With all these features, the users will be able to instantly and smoothly resolve and learn analysis and design results.

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How to estimate the quantity of reinforcement

In order to figure out the accurate cost of the structure, the proper idea on the quantities of the materials together with the reinforcement should be considered. One can estimate the proper quantities concerning the concrete and brickwork out of the layout drawings. In case the working drawings and schedules for the reinforcement are unavailable, the estimation should be made on the basis of the predictable quantities. The quantities are generally spcified consistent with the conditions of the Standard method of measurement concerning the building works.

To deal with the reinforcement quantities the followings are required :

1. Bar reinforcement is explained separately with steel type (e.g. Gentle or high-yield steel), diameter and weight and seqregated as per the following : (a) Element of structure, e.g. foundations, slabs, walls, columns, etc., and (b) Bar ‘shape’, e.g. straight, bent or hooked; curved; links, stirrups and spacers.

2. Fabric (mesh) reinforcement is defined separately with steel type, fabric type and area, segregated as per (a) and 1(b) mentioned above.

In order to estimate the reinforcement quantities, various techniques are used and amid them the followings three techniques are most recognized :-

Method-1 for Reinforcement Estimation: This method is easy to use and it is created on the basis of the type of structure and the volume of the reinforced concrete elements. As for instance, common values are :-

• Warehouses and identically loaded and proportioned structures: 1 tonne of reinforcement per 105m3

• Offices, shops, hotels: 1 tonne per 13.5m3

• Residential, schools: 1 tonne per 15.05m3

Although this method is used to examine the total estimated quantity, but it may not be completely correct. Besides, lots of expertize are required to break the tonnage down to Standard Method of Measurement requirements.

Method-2 for Reinforcement Estimation: The other useful technique is to apply factors for transforming the steel areas captured from the preliminary design calculations to weights, e.g. kg/M2 or kg/m as suitable to the element.

If the weights are divided into practical, This technique offers a logically perfect judgement if the weights are segregated into functional bar diameters and shapes. Though the factors strongly accept a degree of standardization both of structural form and detailing.

This method is treated as relatively adaptable and accurate in practice, since it is formed with reinforcement requirements established by the preliminary design calculations.

Method-3 for Reinforcement Estimation: Under this technique sketches are created toward the ‘typical’ cases of elements and then weighted.

This method offers the following benefits :

• The sketches denotes the existing structure

• The sketches consist of the intended form of detailing and distribution of primary and secondary reinforcement

• An allocation of supplimentary steel for variations and holes are created through inspection.

This method is also suitable for calculating or analyzing the factors narrrated in method 2 as it consider the individual detailing methods.

In order to make the reinforcement estimate, the importance should be given on the following items :

• Laps and starter bars: A rational allowance concerning normal laps in both primary and distribution bars and for starter bars should be allowed. It should also be verified wheather special lapping arrangements can be applied.

• Architectural features: The drawings should be analyzed properly and plentiful allowance made for the reinforcement is necessary for such ‘non-structural’ features.

• Contingency: A contingency ranging from 10% and 15% is to be included considering some modifications and probable errors.

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5 QUESTIONS TO INQUIRE BEFORE YOU CHOOSE A ROOF

One should not always speed up while come to the final opinion on repairing the perfect roof. It can be a newest purchase or just a substitution of the existing one, no matter what the situation is, one ought to think vigorously before making a buy. To select the perfect roof for your use, you first must learn about what purpose it will serve; sooner or later, it will help you to make a decision. Even after you are at confusion of what must be the basic reason to choose the perfect piece, go through our suggestion for a pertinent solution.

Building construction

An important feature to look for while deciding on the roof is the structure of the building. The plan or layout of a particular construction for which you are looking for a roof might give you a fine idea about what really should be the thing to invest in.

Another thing to keep in mind about the building is its maintenance. If it is used as office with a workforce operating 24/7 the maintenance costs might be a little higher, although when it is more of a branded house the maintenance cost might be less. So make sure you study the usage beforehand.

Roof according to locality

It is an important thing to consider before choosing the roof. For different climates manufacturers have made different types of roof made out of various materials that will serve best for various climate types. For hotter places white roofs will be a good choice whereas a place having leakage problems slanted roofs are stated ideal.

Location of building

The exact location of your building that needs roofing is also an important point to keep in mind. The directions towards which the house is facing, the direction of winds, and all these factors matter a lot to ensure longevity of the roofs. Different materials works differently at given climate conditions, choose the best for hot places, and look for the ones that gives better safety during the rains.

Choosing the membrane

Membrane roofing can make leave people in utter confusion. If you are not well aware of the consequences or advantages of membrane roofing, it’s better to get an overall idea from the contractors. Get a clear idea of thermosets will be useful or you should invest in bitumens.

Budgeting

An important aspect is obviously the cost of the product. Who doesn’t want to make the roof look beautiful, but one must find out ways to find the best roofing option without investing an enormous amount. Do proper research on the height and thickness and the material the contractors are using, get the market rate and do some negotiations to settle in a pocket friendly rate.

Image Courtesy: onartc.wordpress.com

Reference:- seekyt.com

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www.costestimationjournal.quantity-takeoff.com

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Brief overview of Reinforced concrete and its various advantages

Reinforced concrete alias RCC is recognized as the most useful construction materials amid AEC sectors. It contains steel at its base and is enclosed by concrete. By combining these two materials, it becomes very strong and durable.

Now-a-days most of the buildingstructures are constructed withreinforced concrete.

Why RCC is different as compared to other construction materials:-

• The strength & longevity of RCC is very good as it is formed with both steel and concrete.
• RCC is extremely fire resistant as compared to other building materials and it is superior in tension.
• RCC can be easily casted into any required shape by keeping the structural strength and stability intact.
• The yield strength of RCC surpasses 100 times as compared to its tensile strength that results in yielding yield rigid members by least deflection.
• A reinforced concrete structure with walls, dams, piers and footings can be managed easily.

A RCC building structure consists of reinforced concrete slab design, Reinforced Concrete Beam design as well as design of several other components like columns, frames, andfooting and RCC walls.

How reinforced concrete facilitates structural design: Once the architectural design is completed, a structural engineer starts his work for finding out the best fitting structural system to build up the structure on the basis of architectural design. After the erection of the building and setting up of other structural arrangements, there may exist various design issues which should be resolved through structural design capabilities.

Modeling and Detailing of Reinforced Concrete Structures: Some diversified toolset are applied for modeling and structural detailing of reinforced concrete. Various structural components are modeled which range from precast concrete, cast in place concrete and other special construction elements. By applying these tools, civil engineers and structural engineers get the ability to produce models with superior structural detailing and labeling.

The 3D models generated from structural detailing plans may involve interactive sections, smart symbols and marking as well as associative and dynamic dimension lines. As detailed information is embedded in the model, the engineers can test out clashes across the structural discipline inside and identify interdisciplinary clashes too.

Ref: archinect.com

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Interpreting blueprint and floor plan

This is actually a learning process about how to interpret floor plans. A floor plan in the architecture and building engineering is a diagram which is used for scalling rooms, vacant spaces and features at the structures.

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A position is vacant for Estimating Assistance

An USA based manufacturing company is looking for an Estimating Assistance having expertise in math and computer.

Job Role:

• Work in tandem with estimating team and carry out quantity-takeoffs.

• Generate and keep up company database encompassing pricing & cost analysis.

• Perform estimates regarding planning, organizing, bids preparation, determination of most cost effective bid proposals.

Eligibility:

• Capability for reading, evaluating and interpreting blue prints, technical procedures, and project specifications.

• Ability to provide information efficiently as well as solve the queries submitted by groups of managers, clients or customers.

• Ability to handle mathematical concepts like fractions, percentages, ratios, and proportions in practical situations.

• Deal with practical problems as well as diversified concrete variables effectively.

• Proficient with computer skill and applying MS Excel (creating formulas, pivot tables, etc.)

An Associates or Bachelor's degree is required.

The candidates who just completed their graduation, can also apply.

The working hours will be from 8am - 5pm and the pay-scale will range from $14-$15/HR.

APPLY ONLINE

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Increase the tenure of your building construction with ‘PURe'

Make your construction process smarter with 'PURe'. It is a strong & hard polyurethane based product having timberless body structure.

The product is water resistant and improves the longibility of the building structure to a great extent.

Watch the live demonstration.

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