Some useful tips for machine foundation design

Before starting the detailing work for foundations, the following general needs concerning machine foundations should be fulfilled and the results should be verified.

1. The foundation should have contained the capacity to bear the superimposed loads devoid of producing shear or crushing failure.

2. The settlements should have been inside the allowable limits.

3. The amalgamated centre of gravity of machine and foundation should have been maintained in the equivalent vertical line like the centre of gravity of the base plane.

4. There should have been no resonance, therefore the normal frequency of the foundation–soil system should have been either too big or too small with regard to the operating frequency of the machine. Toward low-speed machines, the natural frequency should have been high.

5. The amplitudes under service conditions should be maintained under allowable limits which are recommended by the machine manufacturers.

6. All rotational and correlating parts of a machine should be well-adjusted efficiently with the purpose of reducing the unbalanced forces or moments.

7. If necessary, the foundation should be planned in an efficient way with the intention of allowing a consequent adjustment of natural frequency by adjusting the base area or form of the foundation as may be essential afterward.

To read the complete article, go through the following link. theconstructor.org

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Published By

Rajib Dey

www.constructioncost.co

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How to create a prestressed concrete unit on a prestressing concrete plant

Go through the following construction video that shows how to develop a prestressed concrete unit (Double T) on a prestressing concrete plant.

Double T is a multipurpose prestressing unit usually applied in parking structures but also be utilized in various buildings together with office buildings, industrial buildings etc. The Double Ts contain the potentiality of supporting span extending to 60ft as well as upto 120ft.

Step 1:
The initial step is to set up the necessary forms (here double T) as soon as the cleaning is completed. Under this construction video, a bed is arranged for 5 double T units having length 60ft long. Self stressing form is ideal for prestressing which can deal with prestressing compression force as well as the eccentricity of the strands.

Step 2:
The crew members can arrange strands in the form and transit them through prestressing plate. Strands are placed constantly over 5 units and later on segregated with the space provided by the dividers.

Step 3:
Strands already set in 2nd step are then tensioned to about 2 to 5 kips on the basis of gauge pressure reading. Here a mark is given on strands once the preload is applied. The strands are then tensioned and noted through gauge pressure on hydraulic pump. Quality control Technician then verifies elongation of strands against theoretical elongation. It necessitates that force on gauge and elongation measured should be equal with 5% tolerance limit. If it fails then strand should have been detensioned and then tensioned again.

For more information visit this link.

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Published By

Rajib Dey

www.constructioncost.co

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How to use plastering machine for plastering and cement of a building

This construction video shows how to get rid of the manual process for plastering and cement of interior and exterior of a building by using a cement plastering machine.

The machine plastering is the modern technique to perform the plastering work quickly with a spray textured finish. It also provides more consistent and cleaner look as compared to manual plastering. The building contractor can find this machine plastering system useful to fulfill the tight deadline timely as well as maintain large projects on schedule.

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Published By

Rajib Dey

www.constructioncost.co

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Construction Equipments and their various usages

The site managers and construction planners should have clear ideas on the features of the leading construction equipments which are extensively utilized in various construction projects. The on-site productivity mainly depends on the amount of time needed and effort which can be significantly affected by the improper selection of type and size of construction equipments.

Excavation and Loading: One family of construction machines intended for excavation is generally categorized as a crane-shovel.

The crane-shovel consists of three most important components:

• A carrier or mounting which offers mobility and stability for the machine.

• A revolving deck or turntable which includes the power and control units.

• An attachment located forepart that provides the special functions in an operation.

The crawler mounting is specifically useful for crawling over comparatively rugged surfaces at a construction site. Other types of mounting range from truck mounting and wheel mounting offering superior mobility amid job sites, but superior surfaces are needed for functioning efficiently. The revolving deck contains a cab to accommodate the person responsible for operating the mounting and/or the revolving deck. Here in figure 2, the types of front end attachments might contain a crane with hook, claim shell, dragline, backhoe, shovel and piledriver.

Typical Machines in the Crane-Shovel Family: Here a tractor contains a crawler mounting and a non-revolving cab. If an earth moving blade is connected to the forepart of a tractor, the assembly is termed as a bulldozer. If a bucket is connected to its forepart, the assembly is called as a loader or bucket loader. There exist various types of loaders which caterer to most competently deal with materials containing diverse weights and moisture contents.

Scrapers refer to multiple-units of tractor-truck and blade-bucket groups with different combinations to allow the loading and hauling of earthwork. Most important types of scrapers consist of single engine two-axle or three axle scrapers, twin-engine all-wheel-drive scrapers, elevating scrapers, and push-pull scrapers. Every type contains dissimilar characteristics of rolling resistance, maneuverability stability, and speed in operation.

For more information visit, theconstructor.org

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Published By

Rajib Dey

www.quantity-takeoff.com

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