UNIVERSITY OF COLORADO CEAE DEPARTMENT FACULTY MEETING ... · UNIVERSITY OF COLORADO CEAE DEPARTMENT ... $15 Billion in direct costs ... Thermal Shear Strength Geotechnical Engineering

1 | P a g e

UNIVERSITY OF COLORADO CEAE DEPARTMENT

FACULTY MEETING MINUTES

Date March 20, 2013 Time 12:00 PM – 1:00 PM

Facilitator Keith Molenaar Scribe Morris

Location ECCE 1B41

Subject Bi-Weekly Meeting

Attendees See Attached

Key Points discussed

No. Topic Highlights

1 2012-13 Faculty Search Updates

The department was searching for one environmental engineering candidate. Due to the excellence of the candidates and the growth of the undergraduate environmental program, the dean has approved two hires – the second being a college growth position. Two offers have been made. After 3/22/13, all candidates will be evaluated and our upcoming recommendations will be forwarded to Rob Davis.

2 CEAE Enrollments – Good News

Initial CEAE admissions offers are at 101% compared to end of season last year. The college as a whole is at 92% compared to end of season. CEAE is currently at 65% enrollment confirmations compared to last year’s final enrollment numbers and compared to the college at 47%. There are 98 admission offers for ArchE and 139 for CivE.

3 NSF Career Project Overview

John McCartney, Matt Hallowell and Abbie Liel gave presentations regarding their NSF Career Projects. Each presentation addressed the three objectives of the projects - teaching, research and outreach. See the attached presentations.

A Multi-‐Scale Methodology for Assessing the Reductions in

Seismic Risk Possible through Building Retrofit Design & Policy

from Buildings to Communities

NSF CAREER Award Abbie Liel March 20, 2013

Motivation

•  Older buildings contribute disproporBonately to losses and

fataliBes in earthquakes.

•  Few requirements that owners seismically retrofit and voluntary

rates of retrofit are low: only 1-‐8% of older buildings.

•  State and local policy mandaBng or incenBvizing retrofit is the

primary measure for overcoming barriers to retrofit, but the

impacts of these policies on safety of the built environment are

not well-‐understood.

Seismic Risk Assessment of Individual Buildings with and without Retrofit

Seismic Risk Assessment of Individual Buildings with and without Retrofit

Community-‐Scale Seismic Risk Assessments for Existing Buildings

Community-‐Scale Evaluations of Retrofit Effectiveness and Policy Alternatives

Proposed Service Learning Modules •  Intended to prepare today’s students to be leaders in designing,

building and maintaining hazard-‐resistant and sustainable

structures.

•  Service learning acBviBes will focus on energy retrofits, and

structural analysis challenges associated with implemenBng these

retrofits.

•  Modules evaluated through surveys of students and parBcipaBng

organizaBons, student exam responses and FCQs.

4/6/2013

1

Click to edit Master title style

Click to edit Master subtitle style

4/6/2013 1The University of Colorado at BoulderThe University of Colorado at Boulder

Predictive modeling of construction injuries in complex environments

Matthew Hallowell



4/6/2013 2The University of Colorado at Boulder

A Grand Opportunity

6 million US workers employed in construction

1,200 fatalities per year

460,00 disabling injuries each year

$15 Billion in direct costs

Hispanic workers are 18% more likely to be injured

30 % high school students in CO are Hispanic

Only 8% of undergrads and 3% of graduate students at CU are Hispanic

4/6/2013

2




Problem Statement

BIM, Sensing, Augmented Reality may be used to improve safety

Unlimited number of tasks and objects in construction environments.

No reliable and robust data

Research Objectives

Empirically identify fundamental causes of injuries

Reduce dataset to principal attributes

Relate principal attributes in probabilistic models




Framework

Genome projects

4/6/2013

3







4/6/2013

4




Research, Teaching, and Outreach Integration

Research output: probabilistic models of construction injuries based on robust attributes

Teaching: Attribute recognition, site optimization, and control during design and planning

Augmented Virtuality, Video Analysis

Outreach: An integrated approach to sharing new knowledge with students and industry members through combined andragogy and pedagogy.




New approach to integrating research, teaching, and outreach

4/6/2013

5




Targeted Impacts

Recruitment of Hispanic graduate and undergraduate students

Hispanic industry mentors and agents for dissemination

Integration of new attributes with augmented virtuality

Activities packaged for sharing with Skyline STEM, classes, and industry

Improved safety through proactive decisions




People who helped BIG TIME

Ross Corotis

Hari Rajaram

Amy Javernick-Will

John McCartney

Rich Regueiro

Mark Hernandez

Angie Bielefeldt

Balaji Rajagopalan

Paul Chinowsky

Steve Sheldon

4/6/2013

1

NSF CAREER Project Overview

John S. McCartney

University of Colorado Boulder

Presentation to CEAE Faculty

March 20, 2013

Geotechnical Engineering Group

NSF CAREER Project Scope


• Integrated research and education initiative

• Research: Understand issues involved with using spurious heat from buildings and industry to improve the performance of geotechnical systems involving unsaturated soils

• Education: Train student researchers to effectively disseminate research results to audiences with varying levels of technical expertise– Improve personal engagement in educational success

– Start successful careers as leaders in this new market sector

4/6/2013

2

Practical MotivationGeotechnical Engineering Group

• Backfill material selection options for earthen embankments and mechanically-stabilized earth (MSE) walls:• Freely-draining backfills (gravel, sand)

✗ Typically unavailable without hauling✗ Expensive Low influence of degree of saturation

on deformation response• Poorly-draining backfills (silt, low PI clay)

Often readily available Inexpensive✗ High influence of degree of saturation on

deformation response

• Most geotechnical design guides require use of freely-draining backfills (Sabatini et al. 1997)

Stress State in Unsaturated Soils


waa uuu '

Se

nn

wawaa a

uuuuu

11

1'

nn

ea

S

11

1van Genuchten (1980)

Soil-water retention curve

Lu et al. (2010)Effective-stress

parameter

Bishop (1959) Effective stress

Effective stress integrating SWRC

'tan'' Example of dependency of soil properties on effective stress

4/6/2013

3

Thermal Improvement of Unsaturated Soils


Goal: Maintain unsaturated conditions in backfill by inducing thermally driven water flow out of the backfill• Unsaturated conditions lead to greater shear strength and

stiffness of backfill• Include permeable reinforcements (nonwoven geotextiles) to

provide an intermediate drainage path between heat exchangers

• Backfill becomes a sink for sustained heat sources:• Cooling of buildings• Dry cooling for

industrial facilitiesHot

Cold

NSF CAREER Project Scope


Thermo-Hydro-Mechanical Properties of Unsaturated Soils

Thermo-Hydro-Mechanical

Soil-Geosynthetic Interaction

Soil-Geosynthetic Thermo-Hydro-

Mechanical Constitutive Model

Outcome: Dissemination of results to wide audience and recruiting of new students to

STEM fields

Outcome: Engagement of students in success of

interdisciplinary training

Lab TestingCentrifuge-Scale

Modeling

Atmosphere Interaction Model

for Heat/Water Flow in

Thermo-active Geotechnical

Systems

CommunicationTraining

Outcomes:Validated Design

and Analysis Tools;Wider Class of

Backfills Available for Construction;Energy Efficiency

External Presentations

4/6/2013

4

Interesting Phenomena to Study


• Thermally driven water flow in unsaturated soils

• Thermal volume change of unsaturated soils

• Impact of temperature on the water retention of unsaturated soils

• Impact of suction and temperature on the shear strength of unsaturated soils

• Impact of temperature on the shape of elasto-plastic yield surface (thermal softening)

• Impact of temperature on the deformation response of geosynthetic reinforcements

Project Personnel


• John McCartney, PI

• Nahed Alsherif (PhD candidate, post-comprehensive)– Impact of high suction and high temperatures on the shear

strength of unsaturated soils

• CJ Coccia (PhD student, pre-comprehensive)– Constitutive modeling considering mechanisms of thermal

volume change in unsaturated soils

– Thermally driven water flow in unsaturated soils

• Melissa Stewart (PhD student, pre-preliminary)– Impact of temperature on soil-geosynthetic interaction

4/6/2013

5

Thermally Driven Water Flow


Coccia and McCartney (2013)

Thermo‐Hydro‐Mechanical Triaxial Cell System

Components:‐ Suction control system‐ Temperature control

system‐ Mechanical loading

control system• Load control for heating• Displacement control for

shearing


Alsherif and McCartney (2013)

4/6/2013

6

Total stress failure envelope for unsaturated Bonny silt

at room temperature of 23 C

Principal stress difference versus axial strain

at room temperature of 23C

Room Temperature Constant Water Content Triaxial Test Results

0

500

1000

1500

2000

2500

3000

3500

4000

0 1 2 3 4 5 6 7Axial Strain εa, (%)

Prin

cipl

e st

ress

dif

fere

nce σ 1

-σ3,

(kPa

)

Pn=300 kPa

Pn=200 kPa

Pn=100 kPa


(σ1-σ3) = 6.068(σ3 - ua) + 1319.5R² = 0.98650

500

1000

1500

2000

2500

3000

3500

0 50 100 150 200 250 300 350Confining net stress σ3 - ua, (kPa)

Failure envelopeψ= 126 MPaψ= 290 MPa

Prin

cipl

e st

ress

dif

fere

nce σ 1

-σ3,

(kPa

)

Alsherif and McCartney (2013)

Thermal Volume Change


McCartney et al. (2013)

Saturated Soils Unsaturated Soils

4/6/2013

7

Thermal Shear Strength



Yield Stress Stress-Strain Curve

Confinement Effects on Geosynthetic Creep



4/6/2013

8

Communication for Geotechnical Engineers


• Although useful for all engineers, communication skills are essential for geotechnical engineers because of the challenges they face in practice

• Even though the geotechnical component of civil engineering systems involving soils is typically constructed first, the geotechnical engineer is often the last subcontractor to be hired

• The geotechnical component of these systems has a high potential to add inefficiency and risk to a project, as soils are inherently variable

Communication for Geotechnical Engineers


• Prescriptive designs cannot be applied to solve every problem in geotechnical engineering

• Opportunities to develop creative solutions that address site-specific problems in a cost-effective and sustainable manner

• When the geotechnical engineer is hired last, solutions must be conveyed to peers in the design office, owners, architects, structural engineers, contractors, regulators, and construction quality control supervisors

• As these individuals have diverse technical backgrounds, geotechnical engineers who can communicate technical information to audiences with varying levels of technical expertise will be in high demand in the workplace

4/6/2013

9

Educational Plan Objectives


• Developing a communication workshop for student researchers which incorporates lectures on effective communication skills, guided presentation planning using written case statements, and presentation practice with film feedback analysis

• Organizing presentations by student researchers to:– High school freshmen from Denver East High School

– Diverse student organizations housed within the CU BOLD center

– Industry stakeholders in the Geothermal Academy

– National engineering firms

• Assessing the program’s success by comparing audience feedback with students’ written case statements

Documents

UNIVERSITY OF COLORADO CEAE DEPARTMENT FACULTY MEETING ... · UNIVERSITY OF COLORADO CEAE DEPARTMENT ... $15 Billion in direct costs ... Thermal Shear Strength Geotechnical Engineering