Speaker: Christoph Goss, Senior Associate, Tunnels & Underground at Schnabel Engineering

Topic: Nelson Tunnel Horizontal Boring and Submarine Exploration

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner and non-alcoholic beverages provided.

Speakers:
Tony Monasterio with BGC and Todd Roberts with GZA

Topic: Instrumentation Data Acquisition, Transmission, Storage, Visualization, and Modeling

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner and non-alcoholic beverages provided.

Speakers:
Rachel Hunt, P.G., Associate Engineering Geologist, Landslide Technology, Boise, Idaho, and
Benjamin George, P.E., C.E.G., P.G., Senior Associate Engineer, Landslide Technology, Portland, Oregon

Topic: Rockfall Risk Reduction: Investigation, Design, and Construction across Oregon, Washington, Montana, and Alaska

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner and non-alcoholic beverages provided.

Speaker: AEG President Sarah Kalika

Topic: Challenges and Opportunities for Environmental & Engineering Geologists in Professional Practice

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner and non-alcoholic beverages provided.

Speaker: Jahns Distinguished Lecturer Cynthia Palomares

Topic: How Climate Change Impacts Infrastructure

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner and non-alcoholic beverages provided.

Student poster session and two or three 20-minute student talks. Presenters TBD

Dinner and non-alcoholic beverages included. Social hour begins at 5:30, announcements and introductions at about 6:45, talks will begin at about 7 pm.

Submit a Student Night sponsorship — thank you!

Speaker: Brian Collins, Senior Geotechnical Engineer with BGC Engineering

Topic: Pretty Rocks Landslide (Denali Park Road)

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner NOT provided this month —please bring your own dinner, or you can order from the food truck at New Terrain. La Baja Fish Tacos & Grill is on New Terrain’s food truck calendar for Feb 13.

Speaker: Spencer Logan, Science and Operations Officer with the Colorado Avalanche Information Center (CAIC)

Topic: Inside the CAIC’s Forecasting Process

Social hour begins at 5:30, announcements and introductions at about 6:45, talk will begin at about 7 pm.

We will be in the private Terminus Room at New Terrain Brewing. Dinner provided.

Please join us for a casual December social at Cheese Ranch on Thursday, December 14, starting at 6pm. Friends and family welcome. $45 per person. Optional: bring a bottle of wine to share!

Any money left over after we pay Cheese Ranch will go the the CSM Student Chapter.

Speaker: No speaker, just a casual get-together over fondue or raclette.
Topic: Cheese, Wine, and No Stress

Thursday, December 14, 2023
6 pm till Natalia kicks us out
Cheese Ranch
601 16th Street
Golden CO 80401

Our November speakers will be Ben Arndt (RJ Engineering), and Nicole Mapes (CDOT Geohazards)

Topic: Glenwood Canyon I-70 Forest Fires, Debris Flows, and Debris Flow Mitigation

Our October speaker will be Ana Vargo with the U.S. Dept. of Agriculture - Natural Resources Conservation Service, Colorado State Office, on Rehabilitation of Tibble Fork Dam, Utah County, Utah

Please note: if the government shuts down on October 1 and remains shut down on October 10, Ana will not be able to give her talk. We will still have our October chapter meeting; Amy and Jill will figure out an alternative talk or activity.

Abstract: Tibble Fork Dam rehabilitation design included a 15-foot raise in the dam height, cutoff wall, grout curtain, new dam alignment, new downstream berm, additional construction material required for dam raise, and new spillway location on the left abutment. Review of existing data indicated that the site is located in a geologically complex area, that included the potential for liquefiable soils. During the rehabilitation process (2010 to 2016), 28 boreholes were drilled, and 86 test pits were dug. Eight cross sections were generated to demonstrate the complexity of the geology below the dam and berm and help determine the excavation and replacement of liquefiable foundation soils. The stream has cut into a conglomerate, tuff, and Tertiary deposits creating a complex relationship. Youngest alluvium from the current stream was deposited on the tuff, additionally, in a few boreholes, unconsolidated alluvium occurs below the tuff. This alluvium was deposited prior to the volcanic action which formed the tuff. Previously mapped Tertiary volcanics (tuff) deposited in a graben are actually part of the Tibble Formation; therefore, the left abutment fault does not exist as shown on existing maps. However, the possibility of pre-Quaternary age faulting or interfingering of the Tertiary Volcanic rocks of the East Traverse Mountains is possible. The tuff is known to cause landslides. The tuff has characteristics of lean clay (CL), clayey sand (SC), clayey gravel (GC), fat clay (CH), and elastic silt (MH). Much of the dam embankment is founded on relatively pervious alluvium and colluvium requiring a cutoff wall to inhibit seepage beneath the dam. Additionally, the Wasatch Fault occurs about 5.2 miles (8.4 km) west requiring the new downstream berm to enhance embankment stability. The construction of the dam was completed in 2017.

Kristi Ainslie, AECOM:
Determining Treatment Requirements for High-Permeability Faults in a Dam Raise Foundation

Kyle Kittle, Stantec:
Chimney Hollow Dam Foundation Grouting Program, Larimer County, Colorado

Abstracts:

Kristi Ainslie, AECOM Technical Services, Doug Yadon, AECOM; Felipe Garcia, Stantec; Paulo Virreira, Denver Water
Determining Treatment Requirements for High-Permeability Faults in a Dam Raise Foundation
Denver Water is expanding Gross Reservoir by raising the curved gravity dam by 131 feet. The raise will result in Gross Dam becoming the highest RCC dam raise in the world. During original dam construction in the 1950s, geologic mapping of the Precambrian granitic foundation (led by engineering geologist Ernie Wahlstrom) revealed a series of what became known as the “alphabet faults”. Among these faults the parallel “C” and “D” couplet form a 10- to 15-foot-wide zone of highly weathered and sheared rock with increased permeability in the mid right abutment. The faults were treated in the original foundation with additional excavation up to 25 feet. Higher grout takes and tighter hole spacing through the fault zone combined to achieve closure in the original grout curtain. Foundation investigations for the Gross Reservoir Expansion project (GRE) identified the “C”-“D” fault couplet as one of the high-priority targets in the right abutment. In addition to reconnaissance geologic mapping and an inclined 312-foot-long HQ3 core hole, existing foundation drains were televiewed and seismic refraction tomography (SRT) profiles crossing these features were scrutinized. Since GRE construction began in 2022, detailed mapping of the dam raise foundation has located these faults. Treatment of these features at the foundation surface has included additional excavation and replacement with treatment concrete. Televiewing and packer testing of existing foundation drains was performed as the basis for an ongoing assessment of the need for stitch grouting of the “C”- ”D” couplet to supplement the original grout curtain in this area.

Kyle Kittle, Stantec, and Don Riley, Stantec
Chimney Hollow Dam Foundation Grouting Program, Larimer County, Colorado
The Chimney Hollow Reservoir Project is located approximately 8 miles southwest of the city of Loveland in Larimer County, Colorado. The project is a component of the Windy Gap Firming Project, operated by the Municipal Subdistrict of the Northern Colorado Water Conservancy District. When completed the reservoir will impound 90,000 ac-ft of water and will help ensure a reliable water supply for over 800,000 people in Northern Colorado. The main dam will be a rockfill asphalt core dam with an embankment height of 355 ft and a crest length of about 3,674 ft. Construction began in August of 2021 and filling of the reservoir is planned to begin in 2025. Construction cost is estimated to be $510 million.

The project is located in a north-south trending valley along the Front Range of the Rocky Mountains. Foundation bedrock along the main dam alignment consists of a Paleozoic sedimentary unit (Fountain Formation) that is underlain by Precambrian metamorphic and igneous rock (gneiss, amphibolite, and pegmatite). The grouting program for the main dam is using the split-spacing procedure to install multiple blanket rows and a double-row grout curtain. Drilling and grouting are performed from a concrete plinth that is located along dam centerline. Rotary and percussion drilling methods are used for grout hole drilling and stable grout mixes are utilized for injection of all stages.

Speakers: Ian Johnson and/or Brendan McGarity (tentative) with FHWA

Topic: US Highway 50 Improvements Project: Little Blue Creek Canyon, Colorado

Abstract: Reconstruction of U.S. Highway 50 through the Little Blue Creek Canyon (halfway between Montrose and Gunnison) is currently underway. The project is being delivered by the Central Federal Lands Highway Division of the Federal Highway Administration in partnership with the Colorado DOT as part of the Federal Lands Access Program. This program provides Federal dollars and engineering expertise to help states and local agencies improve roadways that access Federal lands, including National Parks, Forests, Recreation Areas, and Wildlife Refuges. This project includes numerous rock cuts and retaining walls to provide improvements to roadway width and geometry. Portions of the rock cuts are in complex geological terrain. Fill side retaining walls are constructed as Geosynthetic Reinforced Earth walls to reduce the wall footprint and shoring needs. This presentation summarizes the design and construction progress to date on the project.

Format will be a poster session and two or three student talks. Presenters TBD

Dinner and non-alcoholic beverages included. Social hour begins at 5:30, announcements and introductions at about 6:45, talks will begin at about 7 pm.

Submit a Student Night sponsorship — thank you!

Speaker: 2022-2023 Jahns Distinguished Lecturer Vince Cronin

Moving Experiences with Landslides: “This topic focuses on landslides (in the broadest sense of the term), including some general background about landslides, landslides I have worked on, and maybe a few others I have studied. With Jim Slosson, I worked on several expensive landslides in Malibu (Big Rock Mesa, Rambla Pacifico, Castellamare, etc.), the Abalone Cove landslide, the Thistle landslide in Utah, and the debris flows I talked about at AEG. I was also caught in a debris flow on a mountain road in the Karakoram-Himalaya in Baltistan, Pakistan. (I lived.)”

Many thanks to BGC Engineering, Schnabel Engineering, and one anonymous donor for their very generous March 2023 Jahns meeting sponsorships!

Speakers: Matt Monteith with CTL|Thompson, and Kanaan Hanna

Topic: Historic Coal Mine Subsidence Hazard Mitigation in the Steeply Upturned Bedrock Area North of Golden

Speaker: Ryan Marsters, Lithos Engineering

Topic: The Spiro Mine Tunnel Water Supply System Rehabilitation

The Spiro Mine Tunnel was constructed from 1916 to 1924 to drain water levels for a honeycomb complex of mines near Park City, Utah. Historical usage has transitioned from mining support to a skier subway, laboratory, and now as a key water supply component. Early construction relied on drill and blast techniques to excavate layered sedimentary rocks. Early support used timber lagging, which subsequently failed and required periodic replacement with steel sets, split sets, chain link, and more timber. To secure long-term water supply, a multi-faceted approach was taken to rehabilitate the failing initial 400 LF of tunnel with modern support techniques and retain the architectural flavor of the area. Not only was the tunnel support rehabilitated, but the water delivery system beneath the tunnel was replaced as well. This presentation will discuss the design elements, construction issues, and ongoing work.

Speakers: Speakers: Todd Roberts and Nate McGee with Bentley Systems / sensemetrics

Topic: Modern IoT (Internet of Things) Applications and Digital Twins

Modern advances in monitoring techniques have blazed the path for innovation towards real time IoT applications that connect us to high risk, remote, and/or critical assets in ways that were not scalable or possible 5 to 10 years ago. Yet today, this single digital connection point to the real world is embraced by a relatively small community of tech savvy engineers and geologists and somewhat isolated from other workflows. In order to maximize the value of this information, we need elevate this information to other stakeholders which requires changes to how we deliver projects. For example, what is the value of this information to a broader and diverse audience? What is a Digital Twin and how can IoT breathe life into a digital representation of a real-world asset for geotechnical and civil infrastructure projects? Join us to learn how to engage in the digital transformation and include it in practice.

Todd Roberts, P.G. | Senior Director, Business Development | Infrastructure IoT
Nate McGee | Director, Business Development | Infrastructure IoT

2022 Rocky Mountain Geo-Conference

Geotechnical and Geological Projects and Case Studies in the Rocky Mountain Region

Speakers: Matt Morgan and Jonathan Lovekin, Colorado Geological Survey

Topic: Meet the New Colorado State Geologist, and CGS Land Use Review Case Histories and Success Stories

Speakers: Christoph Goss, PhD, PE, and Morley Beckman, PE, Deere & Ault / Schnabel Engineering, Longmont, CO

Topic: Finding, Opening, and Stabilizing the Terry Tunnel

The Terry Tunnel served as the primary drainage and haulage tunnel for the Sunnyside Mine from 1907 until 1960 and secondary access until the mine closure in 1991. In 1994, the first bulkhead of the Sunnyside mine was installed in Terry Tunnel, and in 2000, the second bulkhead was installed. Subsequently, the portal was collapsed, backfilled, and revegetated. Prior to the completion of this project, mine water was still draining from the collapsed mine, and the exact location of the buried portal was unknown. Schnabel Engineering (formerly Deere & Ault Consultants) worked with Tetra Tech and the US EPA to perform a fluid hazard analysis for the site. By utilizing historical mine maps and converting them into the state plane coordinate system, Schnabel created planning documents to intercept and drain the mine water from behind the collapsed portal. Even with Schnabel’s coordination between geophysical subcontractors and land surveyors, it took three attempts to successfully intercept the Terry Tunnel.

Schnabel oversaw the borehole sonar and video survey, the downhole methods used to establish the conditions within the adit, the location of the portal and the location of the bulkhead. In the borehole, a temporary well and pump were installed to dewater the adit, collecting the mine water in a nearby retention pond. After dewatering was completed, Schnabel oversaw the excavation of the portal and developed plans and specifications to rehabilitate the 300 feet of adit to reach the bulkhead. Schnabel performed construction management during the rehabilitation, including new steel sets, portal structure, rock bolting, scaling and mucking within the adit. Schnabel performed a bulkhead inspection once the ground stabilization in the adit was completed.

2022 Student Night! We will have a small, casual Student Night at Trailhead on Tuesday, April 19 with two student presenters from the Colorado School of Mines:

Adam Malsam, Evidence for a Repeated Annual Rockfall Cycle at Floyd Hill, a Rock Cut-Slope West of Denver, Colorado

and

John Pultorak, Correlating Seismicity with Geology in an Underground Mine

Speaker: Lynne Carpenter, Geologic Hazards Program Lead, US Forest Service National Headquarters, Lakewood, CO

Topic: The 2021 National Landslide Preparedness Act

Speaker: 2021-2022 Jahns Distinguished Lecturer Rick Wooten

The Building and Upkeep of a Landslide Hazards Program: The Confluence [Collision?] of Science, History, Politics, and Public Opinion – A Blue Ridge Perspective on a National Challenge

Many thanks to Deere & Ault and RJH Consultants for their very generous February Jahns meeting $500 sponsorships!

Meeting cancelled due to high COVID levels and low attendance. Talk postponed to October 2022

Eric Bilderback, PhD, LG - Geomorphologist with the National Park Service, Geologic Resources Division

NPS’s Unstable Slope Management Program (USMP) and Continuing Vibrating Wire Rockfall Monitoring

Speaker: Del Shannon, P.E., Principal / Senior Vice President, Schnabel Engineering

Topic: Beer is for Drinking...Water is for Fighting! An Overview of Front Range Water

Approximately 5 million – or roughly 85% – of Colorado’s population lives along the Front Range; however, the area only receives about 15 inches of precipitation annually. The water needed to support these communities must be captured, stored and transported to the Front Range from areas where precipitation is more abundant. This presentation describes some of the elaborate and complex systems that provide water to Colorado’s Front Range, and also discusses some of the future projects that are being undertaken to continue to deliver water to this area.

Ed Friend, USCAE: 20 Years of Lessons Learned - Looking Back on a Dam Rewarding Career
Tom Terry, USACE Risk Management Center: ALARP Design Considerations for Dams and Levees

Abstracts:

Ed Friend, USACE
20 Years of Lessons Learned - Looking Back on a Dam Rewarding Career
Geological and geotechnical engineering are rooted in observing processes and identifying trends in data. Terzaghi was a master at this concept and sadly many of his lessons have been forgotten or not learned. As a profession we need to share not only our successes, but also our failures, near misses, and stressful situations, because it is from these events where we truly learn. This presentation will depict several lessons learned from the presenter’s personal experience and lessons he has identified as key case histories that helped him throughout his career in dam geological engineering. Lessons learned will deal with differing subsurface site conditions, dewatering of problematic materials, trench stability with slurry supported excavations, stability of clay shales, the value of investigation and construction experience, and others

Thomas A. Terry, P.E., P.G., US Army Corps of Engineers, Risk Management Center, and John Kendall, US Army Corp of Engineers, Jacksonville District
ALARP Design Considerations for Dams and Levees
The presentation will begin with a short definition of what ALARP (As Low As Reasonable Practicable) is relative to life safety risk and how it applies to the design of new dam and levee facilities. The presentation will present various examples of how the authors have provided ALARP related recommendations to planning and design teams for projects based on qualitative risk assessments preformed at the planning (conceptual) stage of project development. The findings of these projects allowed life safety risk to inform the conceptual design of the projects, prior to seeking authority, and helped tailor the project such that they met the intent of risk ALARP as they enter the next phases of design and eventually construction.

Rocky Mountain Geo-Conference
Friday, April 16, 2021 (rescheduled from April 16, 2020)

DoubleTree by Hilton
8773 Yates Drive, Westminster, Colorado 80031

Zoom Student Night
Tuesday, April 6, 2021

6:30 - 7 pm Open forum for socializing and catching up
7 - 9 pm Student presentations with Q&A
Break-out rooms for connecting employers and students

Unless you're a student presenter, there's no need to RSVP.
Technical program and Zoom link will be provided via email the week of March 29

Students: Consider presenting your project as a screenshare over Zoom. Depending on how many presenters we get, you'll have roughly 15-20 minutes total for your presentation and Q&A. If you would like to present, please submit your abstract to aeg.milehigh [at] gmail.com by 5 pm on Friday, March 26. Late abstracts will not be accepted. Once we know how many presenters to expect, we'll create a technical program with schedule. Each presenter will receive a nice gift bag. 

Everyone else: Please plan to join us to support our students and re-connect with the chapter and region. Since we did not have Student Night last year, we are carrying over Student Night sponsorships from 2020. If you would like to submit a new sponsorship, or add to last year's sponsorship, please start here. Instead of individual student presentation awards (it was too difficult to get judges), we are still planning to divide sponsorship contributions evenly among the Mile High Chapter, the CSM and SDSMT Student Chapters, and the AEG Foundation. Thank you to our 2020 and 2021 sponsors!

Employers: If you would like a breakout room during Student Night to meet with or interview prospective employees, please let us know at aeg.milehigh [at] gmail.com. We will publicize your interest in meeting with prospective hires in email reminders between now and Student Night, and will set up set up breakout rooms in Zoom during Student Night.

Since travel to Golden for Student Night this year will be a non-issue, we'd like to include more colleges and universities. If you know of specific professors in geology or earth science departments at schools in the Rocky Mountain-Prairie region who we could reach out to, please email us at aeg.milehigh [at] gmail.com. Thanks