How to set up line and grade in sewer sanitary system construction

n order to place grade and line for developing the sanitary sewer system, four methods are mostly applied. One of these methods or combination thereby may be utilized in the construction. Given below, the detail information on these methods.

Methods of Setting Line and Grade in Construction of Sewer Sanitary System:

1. Stakes or crosses are set up on the surface on an offset from the centerline of sewer sanitary
2. Stakes are set in the bottom of the trench on the sanitary sewer line since the rough grade for the sanitary sewer is finished.
3. Elevations provided for the finished trench grade and sanitary sewer invert whereas sanitary sewer construction proceeds.
4. A laser beam of light set in the manhole or a particular height over sanitary sewer flow line.

1. Stakes or crosses set up on the surface on an offset from the centerline of sewer sanitary: In general, this method is very effective for small diameter sewer sanitary system. Substantially, crosses, stakes, or spikes are arranged at a consistent offset from sewer sanitary centerline.

The excavated soil material should remain at one side of the sewer sanitary trench and the stakes should be arranged at the other side.

If it is required to accomplish an accurate and reasonable job, there should be perfect sheet on which reference points of sanitary sewer stations, offset, and vertical distance from each reference point from projected sanitary sewer invert will have to be recorded.

Finally, the line and grade of sewer sanitary is transmitted to the bottom of the trench with tape and plumb bob unit or tape and level.

2. Stakes are set up in the bottom of the trench on the sanitary sewer line because the rough grade for the sanitary sewer is finished: This method is ideal for large diameter sanitary sewer as well as the sloped trench wall.

For the sloped trench wall, the top width of the trench should have been significantly wide, and the deployment of short offset would not be recommended.

Under this method, surface references are transmitted to the stakes which are arranged at the bottom of trench along sanitary sewer system.

When stakes are set up at the trench bottom, string line should have been drawn among at least three points. The string line should be examined by applying the same process for batter boards.

How to set up line and grade in sewer sanitary system construction

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Arka Roy


Benefits of raft foundation

Raft foundation stands for a type of foundation developed for the reinforced concrete slab having consistent thickness (150 mm to 300 mm) that expands over the large area particularly whole footprint of the building.

It provides support to the columns or walls and transmits the load from structure to large area of ground. Once it is built up, it seems mat of concrete extends over large area, as a result it is also known as mat foundation.

The slab bears the load of entire building and delivers it to ground, so it is assessed to float on ground similar way the raft floats on ground.

Raft Foundation is effective under the following situations :-

When the soil at site contains a low bearing strength, thus load required for being allocated over big area.

When it is ineffective to arrange individual or any other type of foundation. As for instance, when the strip foundation would encompass 50% or more area of building footprint, in such conditions raft foundation is very useful.

When there are chances for unnecessary settlement or differential settlement, when other type of foundation is arranged. In this way, settlement chances are minimized by setting up raft foundation.

When the soil situated below is unstable and might comprise of pockets of easily compressible soil, which may lead to individual footing failure. By arranging raft foundation, this risk is reduced.

If it is required to build up basement, raft foundation is necessary. It’s unreasonable and creates various issues if other types of foundation are arranged except for raft foundation at the time of providing basement. Raft foundation is very suitable for transmitting load and also functions as a floor for basement.

Why raft foundation is necessary if the bearing strength of soil is low?

Generally, it is found that if the soil contains low bearing strength, the raft foundation is arranged at site.

Benefits of raft foundation.

Raft foundation transmits the total load of the building to the soil below.

The deign of raft foundation is simple.
The total load on building (dead + live + other loads + self weight of building and foundation) is estimated.

This total load of building is divided with total area of foundation (i.e. footprint of building). It provides us stress on per sq.m of soil.

For raft foundation the load transfer area of footing is much more as compared to the other types of foundation, therefore, the stress on soil is much lesser, thus it can be avoided by soil having low bearing capacity. The risk of shear failure can also be resisted.

To get more information on raft foundation, go through the following link

Benefits of raft foundation

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Arka Roy

How to use kani’s method for making analysis of continuous beam

In this construction video tutorial, the renowned civil engineer, Mr. Parag Pal, has briefly explained how kanis method is used to continuous beam that contains fixed ends, to evaluate the beam and obtain the final moments.

The continuous beam comprises of the point load and the UDL load.

This method was developed by Dr. Gasper Kani of Germany in 1947.

The method provides a iterative scheme for employing slope deflection method. It is mostly recognized for frame analysis.

It comprises allotting the unidentified fixed end moments of structural members to adjoining joints, with the purpose of meeting the conditions of continuity of slopes and displacements.


1. Kani’s method circulates the total joint moment at any phase of iteration.

2. The more crucial feature of Kani’s method is that it is self reformative. If any fault occurs at any phase of iteration, amendment is made in consequent steps.

Framed structures are seldom symmetric and dependent on side sway, therefore Kani’s method is considered as greatest and much easier as compared to other methods like moment distribution method and slope displacement method.

To get more information on kani’s method, go through the following video tutorial.

How to use kani’s method for making analysis of continuous beam

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Arka Roy


Different types of beam section in RCC structures

In this construction video tutorial, you will gather information on different types of beam section in RCC structures. Usually, there are three types of beam sections which range from balanced beam section , under reinforced beam section and over reinforced beam section.

It is known that a beam comprises of two components i.e. reinforcement and concrete.

Balanced Beam Section: If the ratio of steel to concrete in a section prevails in such a manner that the strain in steel and strain in concrete attain their maximum values all at once, the section is identified as a balanced or critical section and the percentage of steel in this section is defined as critical steel percentage.

Under-Reinforced Beam Section: Under-reinforced section: A section that contains steel percentage below the critical percentage is called as under-reinforced section. As steel lacks to adjust compression in concrete, the tensile strain in steel attains yield value whereas the highest compressive strain in concrete is under its ultimate crushing value.

The section undertakes large rotational deformations from the preliminary phase of yielding of steel to the final stage of crushing of concrete, providing adequate warning of impending failure.

Given below, an extensive lists of different types of basic geometry formulas :-

Yielding of steel in under-reinforced beam section does not signify that the structure has failed, because if steel yields, extreme deflection and cracking in beam will happen prior to failure which provides sufficient time to occupants to escape ahead of the section fails.

The failure in under-reinforced beam section occurs as the concrete attains its ultimate failure strain of 0.0035 prior to steel attains its failure strain which is greater than 0.20 to 0.25.

Over-Reinforced Beam Sections: Reinforced concrete beam sections, in which the failure strain in concrete is attained sooner than the yield strain of steel is obtained, are known as over-reinforced beam sections.

If over-reinforced beam is designed and loaded to complete strength then the steel in tension zone will not yield much prior to the concrete attains its ultimate strain of 0.0035. It happens because of little yielding of steel, the deflection and cracking of beam does not happen and provide enough warning prior to failure.

Failures in over-reinforced sections happen suddenly. This type of design is not approved in practice of beam design.

To get more in-depth information, go through the following video tutorial.

 Different types of beam section in RCC structures
Published By
Arka Roy

Estimating Integration

How estimation done: Costs are generally estimated with the help of some methods that are found in Time Management idea such as one-point estimating, analogous estimating, parametric estimating and three-point or PERT estimating; besides all of this there is a different kind of estimation named method of estimation.

Bottom-up estimation is involved in the final distribution time of a project where it adds estimation of costs at each activity or work package, turning it up into control units and then finally works on whole project estimate. So the estimated created by following steps:

• Project management software: There is various kind of software that increases calculation speed needed to estimate costs and the calculations included direct, indirect, overhead and fixed cost calculations for many activities.
• Deciding resource cost rates: resources can be various kinds like human resources, vendors, consultants, suppliers, external technicians etc. and the project managers are aware about the involved rate for the resource cost.
• Reserve analysis: It gathers identification of activities with significant risks and resolution of all efforts needs to manage the occurred risks.
• Cost of quality: The quality efforts are divided as Cost of Quality.

In the time working with integration, often it is asked about estimation of interfaces that follows below kind of scenarios:

• In the New implementation of Sap, the project manager has to execute lots of interfaces to join with the previous systems
• In the B2B integration, a lot of new pattern and messages will come
• Movement from one integration broker to another.

When any of the scenarios will come interfaces are estimated by following the steps and the development is shown there:

1. Identification
2. System interactions with supported adapters
3. Specification
4. Development
5. Testing and fixing
6. Transport and configuration
7. Document
8. Going live
9. Support.

All of the steps take extra time that will expand the initial time. The 80/20 principle was invented a long ago that states that spend less time to do more work and if more time spends in the beginning of the estimation then the whole process might take longer time to end. To avoid this scenario, it is important to study about the process and understands it properly then starts the work and as there are more variations of the interfaces that look similar then it will be easy to arrange them as per order.

It must keep in mind that performing estimation is not an easy task as there will be many unknown details about development that can be seem unclear before started; so just go through them and make a detailed report.

Estimating Integration

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Arka Roy


How to calculate volume and area of various complicated geometric shapes

In this construction video tutorial, you will be familiar with various formulas which are essential to measure the area and volume of various complicated geometric shapes.

These complicated shapes range from Trapezoidal pyramid, Right circular cone, Rumbas, Trapezium, Polygon, Circle, Rectangle, Square etc.

Geometry belongs to a section of mathematics that takes care of shape, size, relative position of figures, and the properties of space. It provides a practical means of managing lengths, area and volumes efficiently.

Geometry is segregated into two dissimilar types: Plane Geometry and Solid Geometry. The Plane Geometry is suitable for various shapes like circles, triangles, rectangles, square and more. On the other hand, solid geometry is associated with working out the length, perimeter, area and volume of different geometric figures and shapes. Besides, they are utilized to measure the arc length and radius etc.

Geometry Formula is useful for making calculation of the length, perimeter, area and volume of different geometric shapes and figures. There exist several geometric formulas, which are associated with height, width, length, radius, perimeter, area, surface area or volume and much more.

Given below, an extensive lists of different types of basic geometry formulas :-

Perimeter of a Square=P=4a
Here, a denotes length of the sides of a square

Perimeter of a Rectangle = P = 2(l+b)
Here, l denotes Length and b denotes Breadth

Area of a Square=A=a2
Here, a denotes length of the sides of a square

Area of a Rectangle=A=l×b
Here, l denotes Length and b denotes Breadth

Area of a Triangle=A=b×h2
Here, b denotes base of the triangle and h denotes height of the triangle

Area of a Trapezoid=A=(b1+b2)h2
Where, b1 & b2 belong to the bases of the Trapezoid ; h = height of the Trapezoid

Area of a Circle=A=π×r2
Circumference of a Circle=A=2πr
Here, r denotes Radius of the Circle

Surface Area of a Cube=S=6a2
Here, a denotes length of the sides of a Cube

Surface Area of a Cylinder=S=2πrh
Volume of a Cylinder=V=πr2h
Here, r denotes Radius of the base of the Cylinder and h denotes Height of the Cylinder

To learn the detail calculation process, go through the following construction video tutorial.

How to calculate volume and area of various complicated geometric shapes

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Arka Roy


The process of concrete by weight and volume

atching is defined as the method for computing & combining the various components (cement, fine aggregate, coarse aggregate and water) for the formation of concrete prior to mixing following the mix design.

If this calculation is accomplished based on the volume, it is known as volume batching. Batching is categorized as follow :-

1) Volume batching
2) Weigh batching

Volume batching: In volume batching, the mass of each component is not calculated before batching, rather than there are some fabricated boxes(generally wooden) which are calculated in volume to retain the concrete components.

• This method is normally suitable for small jobs.
• Gauge boxes are applied for estimating the fine and coarse aggregate.
• The volume of gauge box has the similarity with the volume of one bag of cement.
• Gauge bow are also titled as FARMAS.
• They are formed with timbers or steel.
• Normally, they are created as deep and narrow.
• Normally, bottomless gauge boxes are not recommended for application.
• At the time of filling the gauge boxes the material should be filled loosely, no compaction is permissible.

Weigh batching: Weigh batching is the proper and most recognized method of estimating concrete ingredients. Weigh batching is performed in very vital modern concrete batching and mixing plants.

• Batching by weight is better than volume batching in terms of perfectness. Besides, it offers more consistent proportioning. It is always recommended professionally.

• It does not contain uncertainties related to bulking.
• Its equipment’s are divided into 3 general categories.
• Manual
• Semi-automatic
• Fully automatic.
• If batching is done by hand all weighing and batching of concrete are performed by hand. It is suitably for small jobs.

• For semi-automatic batching the aggregate bin gates are opened by operating switches with hand and gates are closed automatically when the material is delivered. This system also comprises of interlock that resists charging and discharging.

The process of concrete by weight and volume

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Arka Roy


A position is vacant for Quantity Surveyor / Estimator

Introduction: A leading medium size business situated in Benoni and engaged with the manufacturing, and installation of Prefabricated Modular Buildings, together with structures and related services, like basic reticulation and civils, is inviting application for a young +- 30 years old Quantity Surveyor who possesses a degree of BSc or BTech (QS).

The candidate should contain at least 5 years experience and onsite experience with contracts with regard to residential housing / Offices / Warehouse construction.

Objective of the job:

• The candidate has to price all the submitted tenders which should contain the following:
• Rate all project costs along with P&Gs, project cash flows, project programmes.
• The candidate should also take responsibility to monitor to commercial prospects of alloted projects and carry out closeout reports.

Duties and liabilities:

• Costings and budgets formation for the allotted projects.
• Tender and contract documents formation together with the bills of materials for procurement.
• Advocating on the procurement policy.
• Accomplishing monthly valuations of work progress, along with forecasting of final costs.
• Estimate, value, submit and negotiate contract variations.
• Control and generate perfect formal reports with reference to the project timelines.
• Recognizing, analysing and developing responses to commercial risks.
• Providing support to general manager with a range of other duties as essential from time to time.

Skill Requirements:

• Technical qualification with a degree in B.Sc (QS) University Degree or B-Tech Degree.
• At least 5 years experience with quantity surveying in South Africa.
• Should contain sound practical organisation skills, planning of resources and programme scheduling.
• Should be capable of providing both summarised and detailed reports on current activities.
• Good knowledge in computer and have the capability to apply Microsoft Office and Microsoft Projects.

• Comprehensible experience in arranging tenders respecting construction.
• Personal Attributes:
• Motivated and determined individual.
• Good speaking power in English.
• Eagerness to travel.
• Good team player and effective communicator.

• Negotiable based on experience

To apply online, go through the following link

A position is vacant for Quantity Surveyor / Estimator

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Arka Roy


SSC Junior Engineer (Civil, Mechanical, Electrical and Quantity Surveying & Contract) Recruitment 2017

Staff Selection Commission is going to arrange an open competitive Computer Based Examination for appointing Junior Engineers Group-„B‟ (Non-Gazetted) posts, in Level-6 (Rs.35400-112400/-) of pay matrix of 7th CPC w.e.f. 5th January 2018 to 08th January 2018.

The last date of submitting application is 17-11-2017.

The written examination through computer will be held on 05-01-2018 to 08-01-2018.

Detail of Posts: Only the male candidates are allowed to apply for the posts of Junior Engineers in Director General. Border

Roads Organisation (BRO), Ministry of Defence.

Reservation: Reservation for SC/ ST/ OBC/ ExS/ PH etc. categories is available as stated by extant Govt. Orders and as announced by the departments reporting vacancies.

The posts are recognized as appropriate for the persons who are suffering from disabilities of forty percent 40%) and above of One Arm (OA), One Leg (OL), Hearing Handicapped (HH) as stated by the Ministry of Social Justice and Empowerment.

To get more information on the vacancies, go through the following link Apply Now

SSC Junior Engineer (Civil, Mechanical, Electrical and Quantity Surveying & Contract) Recruitment 2017

Published By
Rajib Dey


Brief discussion on lap length of bars

Development length and lap length are two vital parts of reinforcement. But there are some basic differences among development length and lap length.

While going to arrange the steel in RC structure, if the necessary length of a bar is unavailable to produce a design length then lapping is essential. Lapping occurs because of overlapping of two bars alongside to attain desired design length.

As for instance, if it is required to construct a 100 feet tall column, but 100 ft long bar will not be available in practical and caging can’t be done in this situation. So, it is necessary to cut the bars frequently to transmit the tension forces from one bar to the other at the position of suspension of bar. So, it is essential to arrange the second bar adjacent to the first bar that is suspended and overlapping should be performed. The amount of overlapping among two bars is called lap length.

For the RCC structure, if the length of reinforcement bars has to be expanded, splicing is conducted to attach two reinforcement bars for transmitting the forces to the joined bar.


The lap length along with anchorage value of hooks should have been as follow :-

1. For flexural tension – Ld or 30d either is larger.
2. For direct tension – 2Ld or 30d either is larger.

The straight length of lapping should not be under 15d or 20 cm.

LAP LENGTH IN COMPRESSION: The lap length in compression should have similarity with the development length in compression calculated but not below 24d.

FOR DIFFERENT DIAMETER BARS: In case of bars with dissimilar diameter should have been spliced, the lap length is computed based on the smaller diameter bar.

LAP SPLICES: Lap splices should not be employed for the bars with greater dia than 36 mm. In this situation, welding is needed. But, in case, welding is not possible then lapping is allowed for the bars greater than 36 mm dia. supplementary spirals should have been around the lapped bars.

For more information, click on the following link

Brief discussion on lap length of bars

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Arka Roy