WHY IS SOIL TESTING A MUST FOR YOUR STRUCTURE

In a recent case, a site went down as the retaining wall collapsed two adjacent buildings. The event took place at the Kapalai Theatre building at Majestic Bangalore. For new construction they have gone up to 80ft soil excavation as a result there were visible cracks in the adjacent buildings.

But this type of incident is happening a lot, so what is the reason

The primary reason is the ignorance on the part of the contractor and builder of not taking the opinion of the Geotech Consultants. The soil composition varies so avoiding its testing and deep investigation further aggravates the situation. Being a recent incident, this should be an eye-opener for all the general public. A soil test with expert supervision is a must.

Soil testing, both for environmental constituents and engineering factors, is hugely important. It is also one of the most overlooked parts of the construction. Two sorts of testing must be done before doing any serious building on soil: (1) the geotechnical engineering tests that tell you whether your soil is fat clay or sandy, silty loam, for example; and, (2) what are the chemical constituents of the soil.

Does it contain something harmful, like volatile organic compounds that need special care or treatment prior to building or during construction

Soil testing is done for measuring the strength and the type of land upon which the building will be built. This is the first stage of building your home. The soil profiles and strength of soil differ from place to place. Some soil can support heavily loaded high rise structures while some cannot even hold a small hut. If the soil under your home is not stable, then the foundation of your building experience differential settlement might crack. Thus, the building might fall.

Performing soil testing can help you in the following cases:

1. Identifying suitable construction materials


2. Identifying the type of foundation needed


3. Helps avoid resting foundations on poor soil or inadequate depth


4. Helps avoid resting foundation on reclaimed soil


5. Helps identify corrosive soil


6. Identify soil liquefaction possibilities during an earthquake

Withstanding levels of soil is an important criterion……

The soil has to take the weight of the structures. The soil must be able to withstand the weight of the building otherwise the loss to property and life can occur. The soil investigations or analysis determines not only the bearing capacity of the soil but also the rate of settlement of the soil. This rate determines the rate of the structure stabilization on the soil. The selection of suitable construction techniques and knowing the possible foundation problems all are based on the results of the soil testing. The water table level of the soil can be known only from the soil testing. The level of the water table shows the likely problem to the foundation of the building and level of humidity within the foundation.

Geotechnical investigation of the soil helps to make better decisions leading to the success of the construction project. The height of the building and the use of materials are decided by the engineers on the basis of soil testing reports. The structure engineers can also decide whether there is a need to go for soil stabilization or increase the depth of the foundation for better stability of the building.

Different types of Soil Testing for building

There are primarily four types of soil testing done for the construction of the building.

• Gravity Test- It is done to get the ratio of unit weight of soil solids to that of the water. This test can be done with Density Bottle Method and Pycnometer Method.


• Moisture Test- In this method samples are collected from the site and weighed before it is put on the oven before drying.


• Atterberg Limits Test- This is done with fine-grained soil to find any critical component from water is present. These are evaluated as, Liquid Limit, Plastic Limit and Shrinkage Limit.


• Dry Density Test- This is done with the Core Cutter Method and Sand Replacement Method.

Soil testing should include an assessment of the behavior of soils under varying conditions of moisture, loading, stress, temperature, etc. so that the design can accommodate both current and potential future conditions.

Conclusion

The foundation is the soul of your building. If it is not perfectly analysed the results could be disastrous. You should always take precautions of testing the soil before planning anything. The surrounding atmosphere of the soil should also be taken into consideration. Be cautious in your approach- ‘prevention is better than cure’.