Y25-780_GEC_Report_Eval_Lakeside_Drive_Pipe.pdf

September 11, 2024

Singhofen Halff 11723 Orpington Street, Suite 100 Orlando, FL 32817

Attention: Mr. Dan Metz, P.E.

Subject: Report of Geotechnical Engineering Evaluation

LAKESIDE DRIVE PIPE CULVERT REPAIR

Orange County, Florida GEC Project No. 5587G

Dear Dan:

Geotechnical and Environmental Consultants, Inc. (GEC) has provided geotechnical engineering services for evaluation of the pipe culvert at Lakeside Drive. This report was prepared in accordance with Proposal No. 11820G dated May 13, 2024. The purpose of this study was to conduct Ground Penetrating Radar (GPR) explorations and evaluate the extent of any voids or raveled soils along the culvert pipe. This report describes our methodology, documents our field investigation and presents our GPR and manual probe findings.

GEC appreciates the opportunity to be of service to you on this project. If you have any questions concerning the contents of this report, or if we may be of further assistance, please contact us.

Sincerely, GEOTECHNICAL AND ENVIRONMENTAL CONSULTANTS, INC.

Ryan J. Petersen, E.I. Daniel C. Stanfill, P.E.

Engineering Intern Senior Vice President Florida License No. 42763

This Report has been digitally signed and sealed by Daniel C. Stanfill, P.E. on the date adjacent to the seal. Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

GEC Project No. 5587G 2 Report of Ground Penetrating Radar Evaluation Lakeside Drive Pipe Culvert Repair

Site Location and Description

The site is located at the Lakeside Drive culvert crossing for the canal, connecting Lake Sue to the north and Lake Rowena to the south in Orange County, Florida as shown on Figure 1. The culvert is approximately 80 feet in length and has residential lots adjacent to it. The mitered end sections at the culvert terminations to the north and south have gabion mattress protecting the slopes. Lakeside Drive does have a patch with an approximate 6-foot by 6-foot dimensions above the pipe culvert from an previous repair, possibly from raveled/migrated soils. Please refer to the attached Figures 1 to 12 and Photographs 1 to 22.

GEC understands that project plans will include installing a pipe liner to stop the deterioration of the pipe culvert, stop soil migration and extend the longevity of the structure while maintaining traffic on Lakeside Drive and vessel traffic through the canal.

Subsurface Evaluation

The purpose of the subsurface evaluation was (1) to evaluate the subsurface horizontal limits of any potential voids/migrated soils using Ground Penetrating Radar (GPR) and (2) to perform manual probes within the pipe culvert through the deteriorated pipe to assess the size of any raveled soil/void areas.

GPR Methodology and Findings

GEC conducted surveys with one antenna: 270 MHz. The maximum penetration depth of the radar signal was approximately 10 feet. GPR linescans were conducted across the top of the culvert with parallel to Lakeside Drive as shown on Figure 2.

The GPR linescans resulted in the following conditions being noted:

• Potential GPR anomalies typically associated with soil migration/raveling were noted in a few of the northern and southern scans that were conducted nearest to the ends of the pipe culvert(Figures 3 to 5 and 12).

• GPR anomalies were also noted beneath the existing patch in the pavement in Lakeside Drive. These anomalies are typically associated with soil migration/raveling and disturbed soils. These anomalies are consistent with what we would expect to see if soil migration/raveling caused a depression in Lakeside Drive and it was repaired (Figures 8 to 10).

GEC Project No. 5587G 3 Report of Ground Penetrating Radar Evaluation

Manual Probing

GEC conducted manual probing within the pipe culvert. Manual probing was conducted in approximately 2-foot intervals beginning at a 1-foot offset from the southern end of the pipe culvert. At each probing interval a slender metal probing rod was moved along the bottom of the culvert to identify if any hole in the culvert existed and, if so, the approximate depth of any raveled soils/voids. This process was extended up from the bottom of the culvert to approximately 6-inches above the water edge.

The manual probing resulted in the following conditions being noted:

• The outer ends/edges and bottom of the mitered end sections of the culvert have significant pipe deterioration for about the first 3 feet of pipe where the edge is below the surface. The voids in these areas are limited to a maximum of 0.5 feet in depth, due to the gabion style mattresses that are around the mitered ends (Photos 1 to 12).

• The culvert pipe and the “mitered end” portion of the culvert were different pipe from the pipe used in the body of the culvert pipe. Based on the joint, it appears as if these may have been “coupled” together at some point (Photos 15, 16, 21 and 22).

• On the south end of the pipe there is an additional utility (estimated 1 foot diameter) that has been set into the pipe body ceiling perpendicular to the direction of the culvert (Photos 13 and 14).

• For the main central body of the pipe, all the deteriorated pipe and subsequent voids were observed at or just above the water’s edge. These voids ranged in depth generally from 0.1 to 0.3 feet, one void extended to a depth of 1 foot (Photos 17 to 20).

Based on the findings of the GPR and the manual probing GEC does not recommend any additional remediation for raveled/migrated soils at the Pipe Culvert, other than the planned pipe liner. If conditions are observed to deteriorate further than described in this report, GEC should be notified to reevaluate our recommendations.

Use of This Report

GEC has prepared this report for the exclusive use of our client, Singhofen and Associates, Inc., and for specific application to this project. GEC is not responsible for any third party’s interpretation or use of this report’s subsurface data, engineering analysis or recommendations without our written authorization.

GEC Project No. 5587G 4 Report of Ground Penetrating Radar Evaluation

GEC has performed the services described in this report in a manner consistent with that level of care and skill ordinarily exercised by members of our profession currently practicing in Central Florida. No other representation is made or implied in this document.

Attachments

Figures 1 and 2: Site Maps Figures 3 to 12: GPR Results

Photographic Logs

FIGURES

Ground Penetrating Radar 2-D Linescans

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Imagery Date: 11/4/23 Figure 1

RPetersen Callout Project Site

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Imagery Date: 11/4/23 Figure 2

RPetersen Callout Pavement Patch

RPetersen Callout Edge of Pavement

RPetersen Arrow

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box

RPetersen Text Box Approximate Location of GPR Linescan:

RPetersen Line

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Date: 6/5/24 Figure 3 Date: 6/5/24 Figure 4

GPR Cross Section ID: 056 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft GPR Cross Section ID: 057 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft

RPetersen Cloud

RPetersen Cloud

RPetersen Cloud

RPetersen Cloud

RPetersen Callout Potential Raveled/Migrating Soil

RPetersen Arrow

RPetersen Callout Potential Raveled/Migrating Soil

RPetersen Arrow

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Date: 6/5/24 Figure 5 Date: 6/5/24 Figure 6

GPR Cross Section ID: 058 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft GPR Cross Section ID: 059 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft

RPetersen Cloud

RPetersen Cloud

RPetersen Callout Potential Raveled/Migrating Soil

RPetersen

Potential Raveled/Migrating Soil

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Date: 6/5/24 Figure 7 Date: 6/5/24 Figure 8

GPR Cross Section ID: 060 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft GPR Cross Section ID: 061 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft

RPetersen Cloud

RPetersen

Potential Disturbed Soil

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Date: 6/5/24 Figure 9 Date: 6/5/24 Figure 10

GPR Cross Section ID: 062 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft GPR Cross Section ID: 063 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft

RPetersen Cloud

RPetersen Cloud

RPetersen Cloud

RPetersen Callout Potential Raveled/Migrating Soil

RPetersen Callout Potential Raveled/Migrating Soil

RPetersen

Potential Disturbed Soil

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, FL

GEC Project No.:

5587G

Date: 6/5/24 Figure 11 Date: 6/5/24 Figure 12

GPR Cross Section ID: 064 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft GPR Cross Section ID: 065 Horizontal Scale: 2 ft Vertical Scale: 0.5 ft

RPetersen Cloud

RPetersen

Potential Raveled/Migrating Soil

PHOTOGRAPHIC LOG

Photographic Log

Client Name:

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

GEC Project No.:

5587G

Photo:

Date:

6/5/24

Description:

Culvert pipe southern mitered end section southern mitered end section, east side of pipe

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida southern mitered end section, west

Date:

6/5/24

Description:

Culvert pipe southern mitered end section, looking north in pipe

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida southern mitered southern mitered

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida northern mitered end section northern mitered end section, western side of pipe

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida northern mitered northern mitered end section, looking south

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida northern mitered northern mitered

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

7/10/24

Cross Utility set into the culvert ceiling pipe near the south end of the culvert pipe.

Cross Utility set into the culvert ceiling pipe near the south end of the culvert pipe.

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

Deterioration at the south joint between the culvert pipe and mitered end section pipe.

The south joint between the culvert pipe and mitered end section pipe.

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

Pipe deterioration and voids near water surface

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

Culvert Pipe looking north.

Singhofen Halff

Project Name:

Lakeside Drive Pipe Culvert Repair

Project Location:

Orange County, Florida

The north joint between the culvert pipe and mitered end section pipe with some deterioration.

The north joint between the culvert pipe and mitered end section pipe with some deterioration.