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?"

[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 (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 hasn’t 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.

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.

[Editor's Note] In this timeless article crafted specifically for GeoPrac, Ed Nowatzki, PE, PhD of NCS Consultants, LLC recounts his experiences working on the geotechnical engineering aspects of the Apollo 11 Lunar Excursion Module (LM or LEM) while working at Grumman in the late 1960's. As most people know, Apollo 11 was the NASA mission where man first set foot on the Moon. But before they set foot on it, they had to set the landing pads of the LM there! How did Ed and his associate, Dr. Leslie Karafiath, come up with geotechnical soil parameters for the design of the LM's footpads? How did they determine a bearing capacity of lunar soil? Click through for this facinating article that I hope you will share with your colleagues. A PDF version of this article is available at NCS' website. (NASA Image) [/Editor's Note]

[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.

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.