Soil Bearing Capacity in Thimphu

Introduction

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 lies in the seismic zone of 4 and 5. This article is about the bearing capacity of soil in Thimphu, 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 express as the capacity of soil to support the load without failure.

In other words,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 school located within Thimphu before construction of school building. These school building are design by School Planning and Building Division (SPBD) assuming the bearing capacity of 150kN/m² and for 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 school 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 school building. Therefore, in collaboration with Bhutan Standard Bureau (BSB) the bearing capacity was conducted. The test was conducted for two pit at the same location of construction for both the school. The practical test was conducted and the sample of the soil was collected for the laboratory test.

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 prescribe 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 condition it is always recommended to check the soil bearing capacity of soil before designing the foundation of the building and other structure.  

Frequently Asked Questions