Eckert_Boise_River_-_Global_Analysis-UPDATED_-_ADDENDUM_TWO.pdf
PDF 118 KB Posted
- Attached to
- Eckert Road Bridges 2147 and 2148– Boise River and Ridenbaugh Canal, Eckert Road and Boise Avenue Roundabout
- Solicitation number
- CT227-01
- Issued by
- Ada County, Idaho
About this file
This addendum document is a geotechnical analysis supporting the Eckert Road Bridges 2147 and 2148 project for Ada County Highway District (ACHD) and related irrigation and municipal agencies in Idaho. The analysis provides slope stability calculations for various structural components of the bridge project, including two abutments and one modular soil-engineered (MSE) panel wall with moment slab. The document presents factor of safety (FS) calculations using Spencer and GLE/Morgenstern-Price analytical methods under both static and pseudo-static loading conditions. Key structural elements evaluated include Abutment 1 with static FS values of 1.50-1.51 and pseudo-static FS of 1.33, Abutment 2 with static FS of 1.50 and pseudo-static FS of 1.34, and the MSE Panel Wall with static FS of 1.73-1.74 and pseudo-static FS of 1.55. Geotechnical parameters specified include reinforced zone materials at 340 lbs/ft³ unit weight with infinite strength, retained soil at 360 lbs/ft³ with Mohr-Coulomb strength characteristics, and native gravel at 340 lbs/ft³. All calculations were reviewed by LM and created by CM on January 30, 2026, supporting the overall bridge design and construction planning for the project with a Notice to Proceed anticipated October 1, 2026, and substantial completion required by June 21, 2028.
The stability analysis demonstrates compliance with minimum acceptable factor of safety thresholds for the bridge foundation and retaining wall systems. The geotechnical conditions documented include fill materials overlying medium to very dense gravels with cobbles and interbedded sand and clay layers, with groundwater present at approximately 22 feet in some locations. Foundation design incorporates driven HP14x117 H-piles at bridge abutments and drilled shafts ranging from 4 to 6 feet in diameter at piers. The pseudo-static loading conditions with 0.06 ground acceleration factors represent seismic design requirements for the Idaho region. This technical analysis forms part of the comprehensive engineering documentation required for bid preparation and construction execution under the estimated $25 million contract value with performance bonds and insurance requirements specified by ACHD.
View the file
Other files
Show 40 more
Latest 50 of 52 listed here. See the rest on GovTribe.
On GovTribe
Work with this file
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
1.501.50
W
250.00 lbs/ft2
1.501.50 Phi
Cohesion (psf)
Strength Type
Unit Weight (lbs/ft3)ColorMaterial
Name Infinite
Strength140Reinforced Zone
340Mohr- Coulomb125Retained
Soil
360Mohr- Coulomb135Native
Gravel
Min FSMethod Name 1.50Spencer 1.51GLE / Morgenstern-Price
25.0
2.0
4.0
23.01
-80 -60 -40 -20 0 20 40 60 80
Abutment 1, Static Reviewed by: LM 1/30/2026Created by: CM
Project
Eckert Road Over Boise River
1.331.33
250.00 lbs/ft2
1.331.33
Phi
Cohesion (psf)
Strength Type
Unit Weight (lbs/ft3)ColorMaterial
Name Infinite
Strength140Reinforced Zone
340Mohr- Coulomb125Retained
Soil
360Mohr- Coulomb135Native
Gravel
Min FSMethod Name 1.33Spencer 1.33GLE / Morgenstern-Price
25.0
2.0
4.0
23.0
0.06
-80 -60 -40 -20 0 20 40 60 80
Abutment 1, Pseudo-static Reviewed by: LM 1/30/2026Created by: CM
1.731.73
250.00 lbs/ft21.731.73
Phi
Cohesion (psf)
Strength Type
Unit Weight (lbs/ ft3)ColorMaterial
Name Infinite
Strength140Reinforced Zone
340Mohr- Coulomb125Retained Soil
360Mohr- Coulomb135Native Gravel
Min FSMethod Name 1.73Spencer 1.74GLE / Morgenstern-Price
16.0
2.0
4.0
11.5
-50 -40 -30 -20 -10 0 10 20 30
MSE Panel Wall W/ Moment Slab, Static Reviewed by: LM 1/30/2026Created by: CM
1.551.55
250.00 lbs/ft2
1.551.55Phi
Cohesion (psf)
Strength Type
Unit Weight (lbs/ft3)ColorMaterial
Name Infinite
Strength140Reinforced Zone
340Mohr- Coulomb125Retained
Soil
360Mohr- Coulomb135Native
Gravel
Min FSMethod Name 1.55Spencer 1.55GLE / Morgenstern-Price
16.0
2.0
11.5
4.0
0.06
-50 -40 -30 -20 -10 0 10 20 30
MSE Panel Wall W/ Moment Slab, Pseudo-static Reviewed by: LM 1/30/2026Created by: CM
1.501.50
250.00 lbs/ft21.501.50
Phi
Cohesion (psf)
Strength Type
Unit Weight (lbs/ft3)ColorMaterial
Name Infinite
Strength140Reinforced Zone
340Mohr- Coulomb125Retained
Soil
360Mohr- Coulomb135Native
Gravel
Min FSMethod Name 1.50Spencer 1.50GLE / Morgenstern-Price
27.0
2.0
4.0
20.5
-80 -60 -40 -20 0 20 40 60 80
Abutment 2, Static Reviewed by: LM 1/30/2026Created by: CM
1.341.34
250.00 lbs/ft2
1.341.34
Min FSMethod Name 1.34Spencer 1.34GLE / Morgenstern-Price
Phi
Cohesion (psf)Strength TypeUnit Weight (lbs/ ft3)ColorMaterial Name
Infinite Strength140Reinforced
Zone
340Mohr- Coulomb125Retained Soil
360Mohr- Coulomb135Native Gravel
27.0
2.0
20.5
4.0
0.06
-80 -60 -40 -20 0 20 40 60 80
Abutment 2, Pseudo-static Reviewed by: LM 1/30/2026Created by: CM
File details come from the government source that posted it. Updated .