Latest Articles - GeoPrac.net

Geotechnical Construction for a Rail Spur at a Rock Quarry

Thu, 04 Sep 2008 09:44:08 +0100

Hello GeoPrac.net readers! I am Robert Thompson, a geotechnical engineer (P.E.) living in Alabama and working all over the U.S. as a partner in Dan Brown and Associates. My first contribution to this site (besides this post!) is an article on a project that I started working on at my previous employer, TTL, Inc., but completed after I joined DBA. Randy has added the article to the downloads area. Read on for a brief summary and the download link.

Geotagging Images for Geoengineers

Thu, 10 Jul 2008 00:47:00 +0100

Geotagging is the process of adding geographic metadata (ie. latitude, longitude and sometimes elevation and bearing) to digital photos or other media. In this article, I will examine the equipment needed, the software to help with the process and what you can do with your geotagged photos. This technology is of great value to geoengineers to present photographic data of a project site either for internal use or for use by clients or others. Despite the title, this article is relevant to anyone wishing to learn how to geotag their photos.

Transient Stability Analyses with SLOPE/W 2007

Wed, 28 May 2008 11:49:49 +0100

Nate Hekman has been a software developer with GEO-SLOPE International since the days when only two developers worked on the user interface of what is now branded GeoStudio 2007. His passion is to make the software so easy to use you dont even think about it, but until that day comes, hes happy to share insider tips and tricks on his blog, Grokking GeoStudio (and the occasional article on GeoPrac.net!).

[Editor] In geotechnical engineering practice we most commonly look at a single set of conditions to anlalyze for a slope stability analysis. In many cases, this is an acceptable approximation of reality. But there are certain times where changing pore water pressures or stress states may warrant a more detailed analysis, a time-dependent stability analysis or transient analysis. In this article, Nate discusses transient stability analyses with SLOPE/W 2007. At the end of the article, he refers the reader to a downloadable example problem for a rapid drawdown condition in both PDF and GSZ (GeoStudio 2007) format. We look forward to more GeoPrac.net contributions from Nate in the future! [/Editor]

VBA and Excel for Engineers and Scientists Part 2

Tue, 20 May 2008 18:29:34 +0100

Microsoft Excel and Visual Basic for Applications or VBA make a powerful combination and a useful tool for scientists and engineers. In the first article in this series, I attempted to give you a basic understanding of VBA and an introduction to the Visual Basic Editor or VBE environment. We also produced our first code (the obligatory "Hello World"). In this long awaited second article in the series, I will dive into the meat of the VBA programming language, including code containers, data types, variables, math operators, built-in functions, flow control, and even debugging.. In the end, you should be able to code some fairly complex things including custom worksheet functions that you can use in your spreadsheet just like a regular formula. Also in this article I give you a sample spreadsheet with some useful utilities that you can use right away. One that is particularly useful is a general interpolate/extrapolate function. Enjoy!

Embankment Dams in Earth Fissure Risk Zones-a Regulator's Dilemma

Thu, 27 Sep 2007 15:32:31 +0100

Earth fissures are a significant threat to various types of infrastructure in the Southwestern United States and elsewhere in the world. They are caused by differing subsidence rates and magnitudes associated with groundwater pumping in alluvial basins. In this article, Ravi Murthy and his co-author Jon Benoist, both with the Arizona Department of Water Resources, examine the impact that earth fissuring has on embankment dams used for flood control. One of their main dilemmas as regulators is: "Is it possible to safely rehabilitate dams in fissure risk zones to continue to provide economical flood protection to the public, or does the risk of dam failure due to an undetected fissure present too great a threat to the public?"

Highway Cut Slopes in Rock: Specialized Excavation and Enhancement Techniques

Tue, 28 Aug 2007 01:08:09 +0100

[Editor's Note] Robert (Bob) Cummings, P.E. of Saguaro GeoServices, Inc. of Tucson, AZ has considerable experience in geotechnical engineering for transportation, heavy construction, and mining. Mr. Cummings has provided geological engineering and geotechnical engineering services to federal, state and local transprtation athorities on both urban freeway and rural highway development projects, involving materials testing, geotechnical exploration in rock and soil, pavement design, retaining walls, drilled shafts, and heavy earthwork in rock and soil, the last including development of rock blasting procedures in sensitive scenic and infrastructure settings. It is this last topic that is the subject of this article, aesthetic blasting and rock excavation. [/Editor's Note]

gINT Professional Software Explained

Mon, 25 Jun 2007 02:30:47 +0100

gINT Professional Software (gINT) is a data management tool for geotechnical, geological and geoenvironmental professionals. But many people only know it as a tool for creating boring logs. The purpose of this article is not so much to train you how to use gINT, but to show you what it can do, and to understand how it treats the data and the reports you make with it and what the implications are to your data and your end products. I will also cover some tips or best practices for successfully implementing gINT. This article was written based on gINT version 7, version 8 has been released but my company hasnt upgraded yet. However, based on a cursory review of changes in Version 8, the content in this article should still be valid for the later version as well.

LRFD for Bridge Substructure Design, Note 2

Thu, 21 Jun 2007 02:26:18 +0100

Naresh C. Samtani, PE, PhD has contributed his second in a series of articles on LRFD for geotechnical engineering titled "LRFD for Substructures - Concept of Failure and Reliability Index". The first aricle was entitled "LRFD for Bridge Substructure Design - A Note on Limit States and Interaction between Structural and Geotechnical Specialists". Click through to read this interesting article.

LRFD for Bridge Substructure Design, Note 1

Mon, 23 Apr 2007 16:01:40 +0100

[Editor May 22, 2007] The author has made changes to this article. It was updated May 8, 2007 on his website, NCS Consultants, LLC. My apologies for not publishing these changes sooner. [/Editor]

GeoPrac.net is very pleased to present this article on Load Resistance Factor Design (LRFD) for Bridge Substructure Design by Naresh C. Samtani, PE, PhD. This will hopefully be the first in a series of technical notes by Naresh on this topic. Through his firm, NCS Consultants, LLC, he is heavily involved in assisting the Arizona Department of Transportation in the implementation of the latest AASHTO code and with developing additional guidelines related to the specific soil conditions encountered in Arizona. He is also the lead instructor for the Ryan R. Berg and Associates, Inc. team of instructors for the LRFD Course for design of substructures offered through the FHWA's National Highway Institute (NHI). Don't miss this great geotechnical article.

VBA and Excel for Engineers and Scientists

Thu, 05 Apr 2007 03:22:52 +0100

Visual Basic for Applications or VBA used in conjunction with Microsoft Excel is a tool that many scientists and engineers have yet to take full advantage of. This article is the first in a series designed to provide you with the basic understanding of how to use VBA and Excel in your practice.