Triaxial Shear Test

Introduction to Geotechnical Engineering Learning objectives of the presentation: Describe the boundary stress conditions for the unconfined compression test. Sketch the setup for a triaxial test showing applied loads and stresses. Draw a free body diagram of a soil specimen in a triaxial test. Given triaxial test data, plot both the total and effective Mohr-circles and determine the strength parameters.

The effect of water on soil strength

ExpeditionWorkshed Professor John Burland explains how important water pressure in the voids between soil particles is in determining the soil’s strength. John describes how major disasters can take place if geotechnical engineers don’t take into account water pressure in soils.

Trench soil collapse

SEMCTRTF This video was produced by the Operating Engineers Local 825 for the OSHA excavation training. Watch the spoil pile angle of repose, lack of set back and the lip on the left of the trench. This is why all trench & excavation rescue incidents should be treated as Class “C” soil and unstable until shored up properly.

Clay heave simulation

British Geological Survey During this video we can see the effect of a clay swelling due to water ingress and the subsequent damage to the house above. This hazard is known as heave and is associated with the shrinking and swelling properties of clays. This tends to be a problem in areas of dry climates subject to occasional heavy rain.

Quicksand simulation

British Geological Survey Here, our lifeguard is about to experience quicksand conditions. Water is pumped in from the bottom of the model to simulate a spring, artesian condition or incoming tide, that may result in sand grains floating and quicksand to develop locally; the effect can be transient and change location rapidly.

SPT test on the bed of river Brahmaputra

Udai Shankar Hazarika A creative method to perform a SPT test! The Brahmaputra, also called Tsangpo-Brahmaputra, is a trans-boundary river and one of the major rivers of Asia. It is the tenth largest river in the world by discharge, and the 29th longest. With its origin in the Angsi glacier, located on the northern side of the Himalayas in Burang County of Tibet as the Yarlung Tsangpo River, it flows across southern Tibet to break … Read more