It is crucial to test the bearing capacity of the soil before designing and laying the foundation of the building, as Bhutan is believed to lie in seismic zone 4 and 5. This article is about the bearing capacity of soil in Thimphu, the capital city of Bhutan.
Soil Bearing Capacity
Soil bearing capacity or bearing capacity of soil is defined as the capacity of soil to resist external load applied to it. In simple terms, it is expressed as the capacity of soil to support the load without failure.
In other words, the SBC of the soil is defined as the maximum average coverage contact pressure between the foundation and the soil which should not reduce shear failure in the soil.
Test for SBC in Thimphu
The soil-bearing capacity was carried out at various schools located within Thimphu before the construction of the school building. These school buildings are designed by the School Planning and Building Division (SPBD) assuming a bearing capacity of 150kN/m2 and for the accommodation of 420 students.
Before constructing the building, it becomes crucial to check the bearing capacity of the soil. The SBC was checked at two different schools namely, Changangkha Middle Secondary School and Lungtenphu Lower Secondary School.
SBC Test Conducted by:
The contractor is required to conduct the bearing capacity test before the construction of the school building. Therefore, the bearing capacity was conducted in collaboration with Bhutan Standard Bureau (BSB). The test was conducted for two pits at the same location of construction for both schools. The practical test was conducted and the sample of the soil was collected for the laboratory test.
A standard penetration test was adopted for checking the bearing capacity at the construction site.
Report for SBC:
The readings are recorded by the technician of BSB and computed by the executive engineer of the same organization. The test report reading was 240 and 384kN/m2 which is greater than 150kN/m2 as adopted by SPBD for designing the school building foundation.
Soil Bearing capacity in Thimphu
The reading of the bearing capacity test report is greater than the prescribed or adopted bearing capacity (that is 150kN.m2) by the designer. Therefore, it is understandable that the local bearing capacity of soil in Thimphu is greater than 150kN/m2 and it ranges from 180kN/m2 to 300kN/m2. However, due to some condition in unfavourable soil conditions, it is always recommended to check the soil-bearing capacity of the soil before designing the foundation of the building and other structures.
Also, read: How to Prepare Structure Drawings
FAQs:
Q: What is the Soil Bearing Capacity in Thimphu?
Ans: The soil bearing capacity of Thimphu usually comes between 180kN/m2 to 300kN/m2 when tested for the pit depth of 1.5m. However, it may vary depending upon the types of soil and the site location. Therefore, it is always advisable to conduct the bearing capacity before designing and constructing the building.
Q: Which is the best engineering materials testing house in Thimphu?
Ans: There are only two testing houses in Thimphu and they are APECS and BSB (Bhutan Standard Bureau). BSB is a government standardisation and certification department. Whereas, APECS is a private-owned company for conducting engineering tests.
