B01_DDIR-ERFO_MP10.21.pdf

FEDERAL HIGHWAY ADMINISTRATION TITLE 23 EMERGENCY RELIEF PROGRAM

FEDERAL LANDS HIGHWAY

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 1 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

Applicant: Forest Service Sub-Applicant: Stanislaus N.F. Region District: Pacific Southwest Region

County:Tuolumne (109) Congressional District: 19 FLH Office: CFL NFLTFI/ NTTFI: Yes

Facility Name: Lumsden Road Facility #: 1N10 Mile Post: 10.21

Federal Project # ER: Financial #:

Federal Project # PR:

Facility Data Facility Type: Road Travel Way Width: 12' Surface Type: Gravel Thickness: 4" ADT: <400 Shoulder Width: 3' Shoulder type: Gravel Thickness: 4" Bridge Type: Bridge ID: Maintenance level: 3

DDIR Cost Summary

Repeat Repair Site: No Concurrent Repair: No Delivery Agency: FS Resiliency Items Included: Yes Non-Competitively Bid: Project Status: Not Started Betterment Included: Yes AOP Required: No Explanations & Justifications:

Due to the large culvert headwalls, we would not be able to replace the culvert with a larger size.

For the larger fill slope failure, due to the geometry of the failed slope and the extent of the damage, we cannot repair the slope in-kind by placing gravel or riprap (rock buttress embankment) because there is not a sufficient catchpoint downslope. After our initial geotechnical analysis and running slope stability models, the least cost repair would consist of installing a retaining wall (soldier pile, sheet pile, MSE or gabion wall). The most suitable design would be determined from additional geotechnical investigations of the remaining fill slope. See attached slope evaluation.

Approvals Step Name Date Status Approver Comments Sub-applicant Supervisor Review

01/04/2024 Approved Douglass Anderson

Slope evaluation preformed on rock buttress option and catching slope option.

FHWA Regional Coordinator Review

01/04/2024 Pending Lorell Duteil

Approval Request Submitted

12/19/2023 Submitted James Duckett

DDIR revised and resubmitted for approval New documents attached: Soldier wall repair justification report from geotechnical engineer; new cost comparisons for wall versus recommended rock embankment; slide models.

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 2 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

Damage Details Inspection Date:05/01/2023

Description and Cause of Damage:

Due to a series of heavy atmospheric river storms and extreme runoff, this site sustained very heavy soil saturation and above normal rain runoff. An undersized culvert at this site plugged up causing the drainage to flow over and along the road surface for 200', which caused heavy rutting in the road surface. It continued to a point where it eventually started running off the fill slope causing a large fill slope failure.

Scope of work:

There are two fill slope failures. One at the culvert pipe outlet end, and another approximately 200' down the road. The failure at the outlet end of the culvert would be repaired by placing riprap along the washed out fill slope failure, replacing the lost road base and surfacing material. Due to the large culvert headwalls, we would not be able to replace the culvert with a larger size.

For the larger fill slope failure, due to the geometry of the failed slope and the extent of the damage, we cannot repair the slope in-kind by placing gravel or riprap (rock buttress embankment) because there is not a sufficient catchpoint downslope. After our initial geotechnical analysis and running slope stability models, the least cost repair would consist of installing a retaining wall (soldier pile, sheet pile, MSE or gabion wall). The most suitable design would be determined from additional geotechnical investigations of the remaining fill slope. The road repairs would need to have new base and surfacing material placed and shaped and compacted.

Comments:

We have determined that a rock buttress embankment would not be appropriate in this location due to the severity of the slide and the geometry of the slope. See attached justification and slope stability models. The next least cost option would be to install a retaining wall with back fill to support the road surface. A more extensive geotechnical investigation needs to be completed to determine the best wall design option for this site.

Damage Type(s) Embankment Collapse – Partial;Drainage - Other;Surfacing Loss/Damage;Roadway Damage Primary Damage Feature: Embankment Primary Damage Feature Condition: Failure/ Collapsed

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 3 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

Repair Costs Details

Location Coordinates

Name Coordinate Type Description Latitude Longitude 2022 CA Dec FS Atmospheric Rivers Default 36.170000000 -119.746200000

01N10_1_MP10.21 Primary 37.832051 -120.096585

Supporting Information

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 4 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

File Name Coordinate Type Description Site 1N10_1 Lumsden Road sketch

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 5 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

20230501_093857

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 6 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

20230501_093930

EMERGENCY RELIEF FOR FEDERALLY OWNED ROADS (ERFO)

DETAILED DAMAGE INSPECTION REPORT (DDIR)

Disaster No: CA2023-1-FS Sheet: 7 of 7

Report Name:

01N10_1_MP10.21

Status: Pending Version No: 3

06/07/2023Version Date:

File Name Coordinate Type Description 20230501_094021

File Name Coordinate Type Description 20230501_093624

File Name Coordinate Type Description 20230501_093356

File Name Coordinate Type Description 20230501_093859

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Notes and Attachments

Title Description Created Date Modified Date 12/19/2023 12/19/2023

01N10_Slope Write Up 12/19/2023 12/19/2023

Model Figures 12-15-23 12/19/2023 12/19/2023

06/29/2023 06/29/2023

Site 1N10_1 Lumsden Road sketch 06/15/2023 06/15/2023

20230501_093857 06/09/2023 06/09/2023

20230501_093930 06/09/2023 06/09/2023

20230501_094021 06/09/2023 06/09/2023

20230501_093624 06/09/2023 06/09/2023

20230501_093356 06/09/2023 06/09/2023

20230501_093859 06/09/2023 06/09/2023