Earth Excavation Checklist The following checklist should be used as a guide for better quality control over earth excavation. (1) Prior to the start of excavation operations, take photographs of the construction area, make sure that sufficient cross—sections are taken, and continue to take progress photographs during construction. (2) Review the log of borings to … Read more
Types of Backfill Materials Different types of backfill materials are used in construction industry. Backfill materials that are commonly used are described below with their engineering properties. 1. Coarse-grained soils Coarse-grained soils include gravelly and sandy soils and range from clayey sands (SC) through the well-graded gravels of gravel-sand mixtures (GW) with little or no … Read more
GEOPHYSICAL TEST METHODS Geophysical test is often used as part of the initial site exploration phase of a project and/or to provide supplementary information collected by widely-spaced observations (i.e., borings, test pits, outcrops etc.). Geophysical testing can be used for establishing stratification of subsurface materials, the profile of the top of bedrock, depth to groundwater, … Read more
Need for Soil Sampling A satisfactory design of a foundation depends upon the accuracy with which the various soil parameters required for the design are obtained. The accuracy of the soil parameters depends upon the accuracy with which representative soil samples are obtained from the field. Sampling is carried out in order that soil and … Read more
DESCRIPTION OF ROCK MASS CHARACTERISTICS Standardized geologic mapping and logging procedures should be used for describing rock mass characteristics. The types of information collected will depend on site access, extent of rock outcrops, and the criticality of the proposed structure to be constructed on or in the rock mass. A method proposed by the International … Read more
Core Recovery and RQD (Rock Quality Designation) The easiest way to characterize the amount of material recovered during rock coring is to calculate “core recovery” as the amount (i.e. length) of recovered material divided by the total length of the core run (presented as a percentage). Rock Quality Designation (RQD) is a modified core recovery … Read more
How to Select Soil & Rock Properties for Engineering Design? A rational approach for selecting soil & rock properties for engineering design can be summarized as a logical twelve-step procedure that covers the 3 primary stages i.e. Site Investigation and Field Testing, Laboratory Testing and Interpretation, and Engineering Design This step-by-step process is presented on … Read more
Depth of Soil Exploration The object of site exploration is to provide reliable, specific and detailed information about the soil and ground water condition of the site which may be required for a safe and economic design and execution of the engineering work. Dr. B.C. Punima Generally soil exploration should be advanced to a depth … Read more
Leaning Tower of Pisa The Leaning Tower of Pisa in Italy is perhaps the most famous tower structure in the world, thanks to its lean (nearly 5.50 out of plumb – Fig-1) which makes it a great international tourist attraction. When the lean started becoming progressive and excessive, threatening its very survival, a geotechnical engineering … Read more
In-situ Tests on Soil In situ testing is a division of field testing corresponding to the cases where the ground is tested in-place by instruments that are inserted in or penetrate the ground. In-situ tests are normally associated with tests for which a borehole either is unnecessary or is only an incidental part of the … Read more