The Arizona Department of Water Resources has an excellent program to monitor a somewhat unique geologic hazard – land subsidence. Caused by compaction of valley sediments in areas of declining groundwater table, it can create significant problems for infrastructure such as drainage facilities, flood control works, and gravity flow utilities such as sewer lines. It can also induce a secondary geologic hazard, earth fissures. The ADWR has been using InSAR data supplemented with GPS surveying and other data since 1997 to monitor a number of land subsidence areas in Arizona. This is the first of what I presume will be a series of comprehensive reports on their program. [Source: Read the PDF report from the ADWR. Image: ADWR Land Subsidence Page]
Related Articles
US 89 Bitter Springs Landslide near Page, Arizona
Changes in Geotechnical Engineering Practice in Arizona
[Editor] Note: NCS Consultants, LLC is Randy Post’s full time employer…ie. my day job! [/Editor]
There are some significant changes being made to the state of the practice in geotechnical engineering in Arizona. NCS Consultants, LLC has prepared three policy memoranda for the Arizona Department of Transportation or ADOT that have been issued to consultants all over the State. These memos are on the topics of bearing capacity and settlement of spread footings and retaining walls, the design of drilled shaft foundations in gravelly soils, and the preparation of drilled shaft axial capacity charts for use by bridge engineers.
Although primarily applicable to upcoming ADOT projects implementing the AASHTO 2007 LRFD code, the memos will have a ripple effect down through other local agencies within the state who frequently defer to ADOT guidelines for geotechnical engineering. Also, the memos and the ADOT/NCS approach to LRFD implementation in geotechnical engineering were presented by NCS at the 2008 TRB Conference in Washington D.C., and many other state DOTs and the FHWA were very excited about the memos. The approach used if not the exact content may become a model for other agencies. More info and links to download the policy memoranda are provided after the break.