Blog Archives

July Dinner Meeting – 2019

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July Dinner Meeting – 2019

Tuesday July 30, 2019 5:30 PM

Speaker: Scott D. Neely, P.E., G.E.

Topic: Identification and Mitigation of an Earth Fissure


There are two projects for which identification and mitigation of known and suspected earth fissures was required.  The first project was the alignment of the 4th segment of Arizona State Route 303L (SR 303L) between Glendale and Peoria Avenues, within the Phoenix metropolitan area.  The second is Northern Parkway between Dysart Road and El Mirage Road, again located within the Phoenix metropolitan area.   In addition to the known earth fissures crossing these major roadways, there are several earth fissures that have been mapped by the Arizona Geological Survey as unconfirmed earth fissures and others that have been identified by Terracon Consultants, Inc. during site reconnaissance of each project area.  A methodical approach consisting of numerous steps was performed for each project to determine which earth fissures could be positively identified, and which ones should be removed from further consideration on the unconfirmed earth fissure list.

The investigative information considered in our analyses included:

  1. literature review,
    1. geology maps showing subsurface stratigraphy
    2. earth fissure maps
    3. lineament analyses of historical aerial photographs
  2. historical survey information showing subsidence in the area
  3. site reconnaissance,
  4. seismic p-wave and ReMi field investigation and analyses,
  5. earth fissure trench field investigation,
  6. discussions with ADOT personnel and MCDOT personnel to decide upon the level of risk each entity was willing to accept in design and construction of their respective roadways.

Based on the information obtained from the foregoing efforts, those unconfirmed fissures not showing any substantial evidence for their existence were eliminated from the list of unconfirmed earth fissures.  For earth fissures for which positive identification or substantial evidence for their possible existence was obtained, measures to mitigate their potential effects to the roadways were modeled by finite element analyses.  Fortunately, none of the earth fissures cross any bridge structures, and therefore, only potential effects to roadway embankments were considered for design and construction and determination of mitigation measures.

The results of the finite element analyses indicated that a high modulus material is needed to distribute the strain caused by the potential differential movement that could impact the roadway embankments constructed across the location of the earth fissure.  A five foot high zone of material having a Young’s modulus of at least 10,000 psi constructed below the embankments will spread 6-inches of potential differential movement occurring over 7 feet beneath the embankment at the fissure locations, to over 30 feet at the pavement surface.  This governed the design of the mitigative measures developed for the project.


Mr. Neely, located in Terracon’s Phoenix office, provides geotechnical and structural engineering consulting for multiple solar developers and contractors nationwide.  He is a member of Terracon’s solar industry technical team of resources providing innovative solutions for a variety of solar clients across the country.  Mr. Neely also provides geotechnical engineering services for multiple other industries including highway transportation (pavement, bridges and slope stability), pipelines, transmission lines, conventional power plants, thermal solar plants, high-rise buildings and airports.  His 30 years of experience includes delivering pile design services for contractors in the solar industry as well as performing geotechnical exploration and design of micro-pile foundations for transmission line towers, anchor tie-back walls, cantilever tie-back walls, cantilever walls, rock slope stabilization, soil nail walls, and mechanically stabilized earth retaining walls. 

RSVP deadline is past


2019 ASU Geosciences Career Night

Join the Phoenix Chapters of the Association of Environmental and Engineering Geologists (AEG) and Geo-Institute (G-I) at the 13th annual student night on April 16th, 2019 from 6-9pm. This is an opportunity for students to learn how diverse the geologic field is and what types of positions are available as a professional. We will pair students and professionals for mock-interviews for the students and lightening talks by professionals. This is also a night for professionals to meet students and learn what they are studying and what they hope to do once they graduate. Don’t miss out on this terrific networking opportunity!                                

The event will be held at the Ventana Room of the ASU Tempe Student Memorial Union (301 E. Orange Mall, Tempe, AZ 85281). For directions, please refer to the map of the ASU Campus and Student Memorial Union, or visit

Cost is 40 dollars for non-members, 30 dollars for AEG or G-I members, and free for all students. A buffet dinner will be provided. For companies wishing to sponsor a table at the event, the cost is $100 per table and will include admission for two representatives. Companies represented with a table will also have sponsorship recognition in a slideshow. There is a limited number of tables and speaker slots available. Please contact Daniel Rosenbalm with G-I at 480-659–4101 with questions, or email

RSVP (including table and speaker reservations) at:

Hosted By: AEG, G-I

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March Dinner Meeting – 2019

March Dinner Meeting – 2019

Posted in Meetings

March Dinner Meeting – 2019

Wednesday March 27, 2019 5:30 PM

Join Us for our quarterly dinner meeting at McFate Brewery next week! Wednesday, March 27, we will have the pleasure of hearing Dr Steve Semken’s presentation “A Brisk Jog on the Trail of Time: Two Billion Years of Grand Canyon Geologic History from the Rim”. You may find Semken’s bio and abstract here. He will be bringing rocks, maps and other visual aids for those in attendance to look at. Don’t miss out on this opportunity to hear from one of the premier geologists studying the Grand Canyon!

We are thankful for HDR for sponsoring this meeting! If you are interested in sponsoring a future AEG meeting, please reach out to Ashley Shirer,

March 2019 Dinner Meeting

Wednesday, March 27, 2019 at McFate Brewery, Scottsdale

5:30 PM Mingling and Drinks 6:30 pm Dinner and 7:00 pm Presentation



Steve Semken, Ph.D of Arizona State University will be presenting: “A Brisk Jog on the Trail of Time:

Two Billion Years of Grand Canyon Geologic History from the Rim”

Steve Semken Bio/Abstract

RSVP deadline is past


Mapping Grand Canyon Conference

Join us February 28 through March 1, 2019 at the Mapping Grand Canyon conference at ASU!

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AEG Holiday Social – 2018

RSVP – Click here

Join us December 3, 2018 for our Holiday Social.

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AEG Holiday Social – 2018

Monday December 3, 2018 5:30 PM

McFate Brewing Company
1312 N. Scottsdale Rd.
Scottsdale, Arizona  (Map)
Come join us December 3, 2018 at McFate Brewing Company for our Holiday Social.

This is a social event and there will not be a speaker.

RSVP deadline is past


September Dinner Meeting 2018 – Joint Meeting with GI


Geotechnical Special Presentation

Arizona Chapters for the Geo-Institute and Association of Engineering and Environmental Geologists Presents:


Speaker: Julian Tao, Ph.D,
Associate Professor at Arizona State University

Date: Wednesday, September 19, 2018 — 5:30 p.m – 8:00 p.m.

Location: McFate Brewing Company 1312 North Scottsdale Road Scottsdale, Arizona 85257

$30.00 Members and Non-Members; $15.00 Government Employees and retirees; $10.00 Students Please RSVP by Monday, September 17, 2018


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2018 ASU Geoscience Career Networking Event


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