Safety, health in excavation

12.JAN.07

The way in which the land is prepared for construction will be one of the areas that the Physical Planning Division will pay attention to when the Building Code is enacted.

In particular, the three areas of focus will be “loads, excavation, and foundation”.

LOADS

There are two broad types of “loads” in the engineering jargon – a “live load” and a “dead load”.{{more}}

A “dead load” refers to the weight of a building on the land and the question will be whether the land can safely accommodate the size of the structure or whether other measures need to be put in place to accommodate the building.

The “live load” refers to things which can move and can be transferred through the structure. Another load to be taken into consideration during the design is a “seismic load”. There is also “wind load” which results from the impact of wind storms, such as hurricanes and tropical storms, on a structure.

When an application is made for the construction of a home or small building, the Physical Planning Division will examine the detailed drawings and plans submitted to ensure that it can handle both the dead and live loads adequately.

EXCAVATION

Safety and health is the primary focus during excavation. The Building Code provides guidelines on how excavations should be secured to avoid the sides collapsing and causing injury or death to workers. It also provides guidelines on how to secure open excavations outside of working hours to prevent death or injury to people on the site as well as to prevent the collection of rain water and breeding of mosquitoes.

The surroundings are also of concern. The code refers to excavation within one foot of the “plane of the natural slope of the soil under any existing foundation”. If the excavation is less than one foot away from the footing of an existing building then precautionary measures need to be put in place to prevent erosion and settlement to existing footing.

FOUNDATIONS

The foundation is another aspect to which the Physical Planning Division will pay careful attention. Of concern is the type of soil on which the buildings will be constructed. On certain types of soils and in certain locations in St Vincent and the Grenadines, soil liquefaction may become an issue. During an earthquake certain types of soil lose shear strength and behave like a liquid, rather than a solid which could result in mass landslides.

There are tests which can be done to determine the risk of the particular soil.

Assuming that all is well with the soil, the Physical Planning Division will determine whether the foundation is appropriately designed for the determined soil capacity. This is even more important when constructing on a slope.

The Guidelines to the Building Code provide information on the types and strength of cement that should be used as well as steel and other building materials.

The Building Code is written in technical jargon designed for professionals such as engineers and architects while the Guidelines to the Building Code is written in a simpler language and is filled with illustrations to explain the requirements.

Further information on the Building Code and Guidelines can be obtained from the Physical Planning Division.