Testing Site Conditions- Part 1

How do you test site conditions at a proposed construction site?

Introduction

This Article explains how to test the conditions at your planned construction site. ?These conditions will influence where buildings can be placed on the site. ?They will also influence your storm-water management plan.?

you will need to understand the purpose behind each test and how to make the math calculations.?

Settling

A big concern when testing soil is whether the soil will be stable enough to hold your building. ?Every soil has some quantity of air between the soil particles. ?The weight of your building will slowly compact the soil, driving out these air pockets. ?This is called soil compaction and will result in settling, or sinking into the ground, of your buildings.

Measuring Slope in the Field

Now you're ready to start testing the proposed construction site. ?The first step is to determine the slope of the land. ?To do so, you will need a ruler and a level.

Slope is defined as the rise divided by the run:

?in order to measure the slope of a piece of ground, you place a level against the ground at the uphill edge of the slope and hold the level horizontally (as shown below). ?At the downhill edge of the level, you measure the distance between the bottom of the level and the ground. ?This distance, divided by the length of the level, gives you the slope:

Soil Permeability

The next step is to measure soil permeability, the ability of the soil to be penetrated by water. ?Permeability is tested using the steps shown below:

The perk value, a measure of permeability, is then calculated as follows:

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So, if the water in the hole above was initially filled to a depth of 18 inches and, after thirty minutes, sunk down to 16 inches, the perk value would be:

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Perk values between 10 and 100 indicate good permeability. ?This type of soil is good for septic tanks but poor for stability of large buildings. ? Impermeable soils, with values greater than 100, are good for another type of sewer system and usually have good stability. ?