Backfill for Figure 3.1:

Conversion factors between cubic metres and green tonnes

Wood Density: Density is the amount of space a mass of firewood occupies, the denser the wood the less space a given mass takes up, or the greater a particular volume of firewood weighs. For example sugar gum weighs approximately 1070kg, while a cubic metre of pine weighs only about 512kg.

approximately 900kg

roughly 24.7 cubic feet

1. Backfill volume = excavation volume – footing volume – wall volume.
2. (Note that only the portion of the wall that is in the trench is deducted, so the height of wall in the trench is the average trench depth minus 2′-0” for the footing: 6′-0” – 2′-0” is 4′-0”)
3. Backfill volume = 207.4 cubic yards.

Calculating the percentage change in height from the wet soil to the dry will give you a measure of the swell factor of the soil. For example, if the dry soil was 1 inch high and the wet soil is 1.54 inches high, divide 1 by 1.54 and multiply by 100 to get a 65 percent swell factor.

Multiply the width of the board (in inches) by the annual change in MC (highest annual MC minus lowest). Then multiply the result by the number from the chart. Because few boards are entirely F/S or Q/S, calculate both numbers and shoot for something between.

Swell: The percentage of original volume that a material increases when it is removed from its bank state and becomes “loose.” When excavated, the material breaks up into different size particles that do not fit together, creating voids that reduce the weight per volume.

The shrink swell test is a simple test that is routinely employed in Australian geotechnical engineering practice to assess quantita- tively the expansive potential of undisturbed or remolded clay soils, and to guide design of footings on these soils.

i. The pressure that heated and softened coal exerts when it is obstructed from free swelling. ii. The pressure exerted by a contained clay when absorbing water in a confined space.

This part IS : 2720 ( Part XLI ) deals with the method of test for determination of swelling pressure of soils. The main purpose of swelling pressure test is to determine the intrinsic swelling pressure of the expansive soil tested.

The shrink–swell index of clay refers to the extent certain clay minerals will expand when wet and retract when dry. Soil with a high shrink–swell capacity is problematic and is known as shrink–swell soil, or expansive soil.

Shrink swell soil is the movement caused by the amount of water in the soil. A lot of rain or a very dry season can change how your soil acts around your foundation. On the opposite end is soil swell. When your area experiences a lot of rain, the soil will swell and expand.

Shrink/swell potential is the relative change in volume to be expected with changes in moisture content, that is, the extent to which the soil shrinks as it dries out or swells when it gets wet. Shrinking and swelling of soils causes much damage to building foundations, roads and other structures.

(Entry 1 of 2) intransitive verb. 1 : to contract or curl up the body or part of it : huddle, cower. 2a : to contract to less extent or compass.

Water in between the layers causes the clay structure to expand, causing the whole soil to expand. When the soil dries, the water trapped between the clay mineral layers is released, causing the whole soil to “shrink.” shrink and swell according to soil moisture.

A type of damage in which formation permeability is reduced because of the alteration of clay equilibrium. Clay swelling occurs when water-base filtrates from drilling, completion, workover or stimulation fluids enter the formation. Clay swelling can be caused by ion exchange or changes in salinity.

Physical and Chemical Properties of Clays Clay minerals all have a great affinity for water. Some swell easily and may double in thickness when wet. Most have the ability to soak up ions (electrically charged atoms and molecules) from a solution and release the ions later when conditions change.

Illite

All clays are susceptible to some shrinkage and swelling due to changes in moisture content. Those with a higher proportion of expansive clay minerals, such as smectite, are even more prone.

Saturated clay soils hold so much water the oxygen is excluded. Clay soil has a high shrink-swell capacity. As the particles shrink they separate and cause cracks, from whisper thin to an inch or more.

In general, those soil classifications that contain the symbol CL (lean clay), CH (fat clay), or SC (clayey sand) indicate the presence of materials that have expansive properties.

Kaolinite has a 1:1 layer structure, and a small base exchange capacity (3.3 meq/100 g for kaolinite). It is non-swelling clay but can easily disperse and migrate [46].