Geotechnical Engineering and Earth’s Materials and Processes

Geotechnical Engineering and Earth’s Materials and Processes — page 3
MINERALS AND ROCKS Geotechnical engineers study minerals rocks and soil so they can design strong safe foundations Minerals are the main substances in rock and soil For example sandy soil and rock called granite often contain the mineral quartz Minerals rocks and soil are the materials that make up Earth’s outer layer called the crust The crust covers the mantle a dense layer of minerals and rocks Where these layers meet heavy rocks push against each other and intense pressure builds The extreme heat and pressure slowly change solid minerals and rocks trapped in this boundary into liquid magma Look at the rock cycle diagram opposite Can you see why heat pressure and magma are important to rock formation Core samples Geotechnical engineers study and test the rocks and bedrock found at new and existing building sites Bedrock is the solid layer that lies beneath the soil It may be shallow or very deep Engineers drill into the rock with hollow tubes that pull out core samples The samples give them a lot of information such as the minerals the bedrock contains Knowing what the bedrock is made up of helps with planning foundations and structures Engineers also test core samples for strength Labs have technologies and equipment that put increasing amounts of pressure on solid rock samples until they break This shows what forces the rock can bear which is important to know before starting the design process 6 These tubes contain core samples of rock that will go to a lab for testing