How to make an estimate: Without losing money

A guide to reliable project estimating - Without losing money 

What is a budget? How is it prepared? 

If you are, or are about to become, involved in the construction industry, electro-mechanical assemblies or other similar activities, we recommend that you watch these videos which detail the steps and precautions to be taken to ensure that your quote is reliable. 

We cover the following topics in this video 

Direct material cost estimation for a job. 

Direct labour hour estimation. 

Cost of machinery and equipment that will be in use. 

How to make an estimate: Without losing money. 

When making a quotation, it is essential to be sure that the price you quote is sufficient to complete the work without any setbacks and to make an economic profit. 

Otherwise, you will not win a job. You will win a problem. 

You can gain new knowledge or refresh existing knowledge about how to prepare an accurate budget in this series of short videos.

Guide to Reliable Estimating

Guide to reliable estimating: A guide for project estimators

Here you will find expert advice for accurate project estimating.

If you are involved in construction, electro-mechanical installation or other similar activities, or if you are just starting out, we recommend that you watch these videos. They detail the steps and precautions you need to take to ensure that your estimates are reliable.

When you bid for a job, it is important to make sure that the price you quote will easily cover all the costs of the job and allow you to make a profit. Otherwise, you are not going to win, you are going to win PROBLEM.

The perfect opportunity to learn or refresh your existing knowledge, this video series is for you. Browse this guide for estimating.

Earthworks

Bulk earthworks

Bulk earthworks refer to the process of moving, excavating, transporting and redistributing large quantities of earth or rock at a construction site.

These operations are usually carried out to prepare the ground for various construction projects, such as building foundations, roads, dams, or landscaping.

Key components of bulk earthworks include:

Excavation

1. Excavation: Excavating and removing soil or rock from the ground using heavy machinery such as excavators, bulldozers, or backhoes.

Excavation is a critical phase of construction projects and requires careful planning, adherence to safety protocols, and compliance with regulations to ensure a successful and safe outcome.

 Cut and fill

2. Cut and fill: This involves cutting higher areas of the land and using that excavated material to fill lower areas, creating a level surface suitable for construction.

Professional surveying, engineering experience, and regulatory compliance are crucial to executing cut and fill operations effectively, while considering the structural, environmental, and safety requirements for the specific project.

Grading

3. Grading: Shaping and leveling land to required elevations and contours in accordance with engineering designs or site plans.

Grading plays an important role in various construction and development projects, including:

Building Foundations: Provide a level, stable foundation for construction.

Road Construction: Establishment of slopes and contours necessary for roads.

Landscaping: Shaping the land for gardens, parks and recreational areas.

Drainage Systems: Ensure adequate water flow away from structures to prevent flooding or water damage.

Hauling and Transportation

4. Hauling and Transportation: Moving excavated materials to designated areas within the construction site or transporting surplus materials off site.

Compaction

5. Compaction: Compact the soil or materials to ensure stability and load capacity, which is relevant to support the structures built on the prepared ground.

The benefits of proper compaction include:

Greater stability and load capacity of the soil.

Minimization of settlements and subsidence, ensuring the longevity of the structures.

Improved resistance to water penetration, reducing the risk of erosion.

Erosion control

6. Erosion control: Erosion control involves the implementation of various techniques and measures to prevent or minimize soil erosion and sediment loss caused by wind, water, or other environmental factors.

It is a critical aspect of construction, land development, agriculture and environmental conservation, which aims to protect soil integrity and prevent detrimental effects on surrounding landscapes, waterways, and ecosystems.

Implement measures to prevent soil erosion, such as installing retaining walls, erosion control mats, or planting vegetation.

Bulk earthworks are essential in various construction projects, as they lay the foundation for the successful implementation of subsequent construction phases.

Proper planning, surveying, and engineering are essential to ensure the efficient and safe execution of bulk earthworks, while meeting environmental regulations and minimizing ecological impact.

The next post discusses the steps to follow to prepare the construction site.

Embankment:

Embankment 

 Steps to make an Embankment:

1. Site Preparation: Assess the area and clear it of vegetation, debris, and topsoil.

  

2. Foundation: Establish a solid foundation by compacting the soil or placing a layer of suitable material to support the embankment's weight. Geotextiles or geogrids may be used to enhance stability.

3. Material Selection: Use appropriate materials like soil, rocks, gravel, or engineered materials to build up the embankment. The material should be compacted in layers to ensure stability.

4. Layering and Compaction: Add layers of material incrementally, compacting each layer thoroughly to minimize settling and enhance stability. Compaction can be done using heavy machinery like rollers or compactors.

5. Sloping and Grading: Shape the embankment to the desired slope and profile, ensuring it meets engineering and safety standards.

6. Drainage: Incorporate drainage systems such as culverts or channels to redirect water away from the embankment, preventing erosion and maintaining stability.

8. Regular Inspection and Maintenance: Inspect the embankment periodically for signs of erosion, settling, or other issues. Regular maintenance, such as repairing drainage systems or adding additional material, is essential to preserve the embankment's integrity.

Factors to Consider:

- Engineering Design: Follow engineering plans and specifications to ensure the embankment meets required standards for load-bearing capacity, stability, and safety.

  

- Environmental Impact: Consider environmental regulations and minimize the impact on surrounding ecosystems during construction and afterward.

- Safety Measures: Implement safety measures during construction to prevent accidents and ensure worker safety.

- Quality Control: Monitor material quality, compaction, and construction processes to maintain the embankment's structural integrity.

In all cases, the filling will be layered with a thickness as to provide adequate compaction. The materials used must have characteristics of granulometry, plasticity, and strength as required by the project

Specifications usually set the minimum required density as a percentage of the maximum density at optimum moisture. This minimum must be achieved everywhere. 

Prior to placing the first layer, the seating surface of the embankment will receive scarification of 30 cm and are compaction until a minimum density of 85%.

The compaction is done in layers of maximum width 30 cm, except for upper layers that do not exceed 15 cm. The Compaction equipment will be appropriate depending on soil type and must use the required pressure for optimum densities.

They pass a test area to determine the number of a minimum of passes of the compaction equipment to perform the sought density.

Operational areas, will be on the natural high ground at least of 0.30 m.

Role of Construction Manager's

Verify the removal of topsoil,

Check that the soil type always provided complies with the indicated by the Soil Study

Constantly monitor the behavior of the bank when one’s move the construction equipment and/or compaction to identify weak areas that are marked or move

If one’s recognize these weak areas or areas that do not meet the specification requirements, shall replace and re-compacted to provide consistent support of the embankment

Check the width of the layers of compaction (remember that if one’s need a compacted thickness of 30 cm, the layer of loose soil is 30% higher or 39 cm)

Run the test described below1.4 Testing

Moisture tests - density are usually performed laboratory personnel at the plant installed.

To evaluate the results of tests of moisture - density field should be determined in the laboratory using the methods established in the AASHTO (American Association of State Highway Officials), the maximum density and optimum moisture content of different soils and materials used in the work.

The density field is determined by digging a hole and carefully extracting the material removed. This material is weighed and taken out of this representative sample to determine the percentage of moisture. One’s can then calculate the dry weight of material removed.

The volume of the sand pit can be measured by weighing known. Subtracting the known weight, the weight of sand remaining after the hole was filled, and dividing that difference by the predetermined unit weight of sand, is the volume of the hole. 

Another method is to measure the volume of water needed to fill a rubber balloon, stretched to determine the shape of the cavity. Detailed descriptions of the equipment and methodology used in the various methods are readily available.

The calculation to determine the percentage of maximum density reached is as following:

V = G1/D1

D2 = G2 / V

D = D2 / (1 + W)

GC = D/Dmx100%

Where:

V = volume of test hole.

G1 = weight of sand needed to replace the soil removed.

D1 = unit weight of sand.

D2 = weight per cubic meter of moist soil.

G2 = weight of moist soil taken from the test hole.

D = weight per cubic meter of dry (no stone larger than ¾ ")

W = moisture content of the sample based on the weight of dry soil (determined by drying a small amount representative of soil removed from the test hole).

Dm = dry weight per cubic meter of soil compacted to maximum density and optimum moisture content (determined in the laboratory).

GC = degree of compaction percentage.

Another way to determine the dry density of soil is through the nuclear density gauge

The Construction Manager must be informed fully and rapid test results.

Besides carrying out tests of moisture — density, verify that the material meets the required fineness. In the uniformity of the filler, it is necessary to avoid changes that are beyond the limits permitted by the specifications.