ATCH_04_Geotech_Engr_Rpt.pdf

GEOTECHNICAL ENGINEERING REPORT

IDIQ Contract No. 140P2021D0012 Provide Title I AE Services for Recreational Use Improvements At Barataria Preserve Marrero, LA

Schnabel Reference No.: 21C19034.00

January 20, 2022

January 20, 2022

DHM Design Corporation 900 S. Broadway Ste 300 Denver, CO 80209-0007 Attn: Mr. Bill Neumann

Subject: IDIQ Contract No. 140P2021D0012 Provide Title I AE Services for Recreational Use Improvements Barataria Preserve, Marrero, LA (PMIS # 317988B) Geotechnical Engineering Report Schnabel Reference 21C19034.00

Dear Mr. Neumann:

SCHNABEL ENGINEERING, LLC is pleased to submit our geotechnical engineering report for this project. This report includes tables, figures, and appendices with relevant data collected for this study.

This study was performed in accordance with our proposal dated September 1, 2021.

We appreciate the opportunity to be of service for this project. Please call us if you have any questions regarding this report.

Sincerely, SCHNABEL ENGINEERING, LLC

Kevin R. Morgan, PE Project Engineer

Richard H. Wargo, PE Principal

Recreational Use Improvements at Barataria Preserve, LA

January 20, 2022 Page i Schnabel Engineering, LLC Project 21C19034.00 ©2022 All Rights Reserved

GEOTECHNICAL ENGINEERING REPORT

RECREATIONAL USE IMPROVEMENTS AT BARATARIA PRESERVE

MARRERO, LOUISANA

TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY

2.0 SCOPE OF SERVICES

3.0 DESCRIPTION OF SITE AND PROPOSED CONSTRUCTION

3.1 Site Description

3.2 Proposed Construction

3.3 Regional Geology

4.0 SUBSURFACE EXPLORATION PROGRAM

4.1 Subsurface Exploration and Field Testing

5.0 LABORATORY TESTING

5.1 Soils Testing

6.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS

6.1 Generalized Subsurface Stratigraphy

6.2 Groundwater

6.3 Seismic Site Classification

7.0 SITE GRADING AND EARTHWORK

7.1 Pavement Section – Gravel Trail

8.0 FOUNDATION RECOMMENDATIONS

8.1 Helical Piles

9.0 CONSTRUCTION CONSIDERATIONS

9.1 Site Grading and Earthwork

9.2 Engineering Services During Construction

10.0 GENERAL SPECIFICATION RECOMMENDATIONS

11.0 LIMITATIONS

LIST OF FIGURES

Figure 1: Test Boring Location Plan

APPENDICES

Appendix A: Subsurface Exploration Data Appendix B: Soil Laboratory Test Data

January 20, 2022 Page 1 Schnabel Engineering, LLC

1.0 EXECUTIVE SUMMARY

This report presents the results of geologic and geotechnical investigations and testing conducted by Schnabel Engineering, LLC. (Schnabel) at the Improvements to the Barataria Preserve, specifically the boardwalk on the Ring Levee Trail. The purpose of the exploration was to acquire subsurface information to provide geotechnical recommendations for the design of the new proposed boardwalk.

We understand the proposed improvements will include the demolition and removal of the existing boardwalk, in which is approximately 225 feet in length, and construction of a new concrete boardwalk.

The project site is located approximately a half-mile in from the parking lot at Christmas Road within the Barataria Preserve. The immediate surrounding area of the existing boardwalk is wetlands with many trees and brush.

Based on the boring data, the on-site soils within the upper few feet of the site predominantly consist of very soft to soft Lean Clay (CL) underlain by interbedded layers of very soft Silt (ML) and very loose Silty Sands (SM).

Shallow foundations are not considered suitable for the support of the proposed boardwalk due to the on-site soils consisting of soft and loose soils within the upper 40 feet. Based on our geotechnical evaluation, it is recommended that helical piles be utilized for the support of the proposed boardwalk.

We understand from the project Structural Engineer that two structural framing options are being considered at the time of this report: 10-foot and 20-foot horizontal spacings for helical piles. Loads have been provided to our office for both options, and a preliminary evaluation of helical pile capacities for the proposed boardwalk is provided herein.

Based on our review of the test borings and geologic data, the soils encountered at the site are representative of IBC Site Class E.

Groundwater was encountered at approximately 11 feet below the ground surface, however, being within the wetlands area, there is standing water in much of the low-lying area surrounding the existing boardwalk. Stabilized water levels were not measured during our field investigation as borings were backfilled at completion for safety. The final design should anticipate fluctuations in the water table depending upon variations in precipitation, surface runoff, pumping from any nearby wells, evaporation, tidal fluctuations, and similar factors. Based on our groundwater observations, we do not expect groundwater to impact the proposed construction. However, the presence of wetlands and standing water will have an impact.

The appendices include detailed information on specific aspects of the investigation, including summary tables and procedures.

We are providing this executive summary solely for purposes of overview. Any party that relies on this report must read the full report. This executive summary omits several details, any one of which could be very important to the proper application of the report.

January 20, 2022 Page 2 Schnabel Engineering, LLC

2.0 SCOPE OF SERVICES

Our proposal dated September 1, 2021 defines the scope of services for this project. The scope of services included the following:

Subsurface exploration, including:

o Advance a total of two (2) soil test borings with Standard Penetration Testing (SPT) sampling to depths of about 30 ft utilizing track-mounted drilling equipment o Backfilling of test borings with drilling spoils upon completion.

Field engineering services, including:

o Site (geologic) reconnaissance.

o Contact State Utility locating service to clear utilities.

o Field coordination and full-time logging of the field investigation by an Engineer or

Geologist.

Laboratory testing of materials encountered in the subsurface exploration, including:

o Moisture Content, ASTM D2216 (3 tests) o Grain Size Distribution, ASTM D6913 (3 tests) o Liquid Limit, Plastic Limit, and Plasticity Index of Soils, ASTM D4318 (3 tests) o Soil corrosivity tests

Geotechnical Engineering Analysis and Report, including:

o Estimated subsurface conditions and groundwater levels within the area explored based on data collected in the subsurface exploration.

o Foundation recommendations for helical anchors for support of boardwalk, including conceptual recommendations for allowable capacities, bearing grades, estimated settlements and frost depth.

o Recommended Seismic Site Class (and Seismic Site Coefficients (Fa and Fv)) in accordance with IBC 2018 for use in foundation design based on data collected in the subsurface exploration.

Services not described in our agreement are not included in this study. We would be happy to provide additional support services to the design team as the project demands.

January 20, 2022 Page 3 Schnabel Engineering, LLC

3.0 DESCRIPTION OF SITE AND PROPOSED CONSTRUCTION

3.1 Site Description

Based on our review of available data and after our site visit, the existing boardwalk is currently sitting upon approximately 6-foot-long timber piles within the wetlands area. The project site is located approximately a half-mile in from the parking lot at Christmas Road within the Barataria Preserve in Marrero, Louisiana. The immediate surrounding area of the existing boardwalk is wetlands with many trees and brush.

We obtained the site information from the site plan, historical data, and through our site visit.

3.2 Proposed Construction

We understand the proposed improvements will include the demolition and removal of the existing boardwalk, in which is approximately 225 feet in length, and construction of a new concrete boardwalk.

3.3 Regional Geology

Louisiana lies within the Coastal Plain physiographic province. Within Louisiana, this physiographic province is divided into the Mississippi Alluvial Plain section found in the eastern portion of the state; and the West Gulf Coastal Plain section covering the western two-thirds of the state. The Barataria Preserve is located within the Plaquemines Parish and lies within the Mississippi Alluvial Plain section. This section is divided into the Mississippi River Delta in the southern half of Louisiana and the upper Mississippi Embayment running from central Louisiana to Illinois. The site lies within the Mississippi River Delta which is characterized by alluvial sedimentary deposits composed of sands, silts and clays deposited during the Cenozoic Era.

January 20, 2022 Page 4 Schnabel Engineering, LLC

4.0 SUBSURFACE EXPLORATION PROGRAM

We performed a subsurface exploration to identify the subsurface stratigraphy underlying the site and to evaluate the geotechnical properties of the materials encountered. This program consisted of Standard Penetration Testing (SPT) test borings. Exploration methods used are discussed below. The appendices to this report contain the results of our exploration.

4.1 Subsurface Exploration and Field Testing

4.1.1 Test Borings

Our subcontractor, PSI – Intertek, Jefferson, Louisiana drilled two (2) test borings (B-1 and B-2) under our observation in November 2021. The Standard Penetration Test (SPT) was performed at selected depths in the borings. Boring B-1 was drilled to a depth of 20 feet below the existing ground surface grade. Due the presence of soft soils with depth, Boring B-2 was advance to a depth of 40 ft. Appendix A includes specific observations, remarks, and logs for the borings; classification criteria; drilling methods; and sampling protocols. Figure 1, included at the end of this report, indicates the approximate test boring locations. We will retain soil samples up to 45 days beyond the issuance of this report, unless you request other disposition.

Due to the very soft soils at the ground surface, and the boardwalk being too narrow for the track-mounted Geoprobe rig to travel on, the drill rig was unable to travel to the far end of the boardwalk to drill boring B-3. There was also no access for the drill rig to the northern end of the boardwalk from the northern. Therefore B-3 was omitted from the subsurface exploration at this time.

January 20, 2022 Page 5 Schnabel Engineering, LLC

5.0 LABORATORY TESTING

Our laboratory performed tests on selected samples obtained during the subsurface exploration. The testing aided in the classification of materials encountered in the subsurface exploration and provided data for use in the development of recommendations for design of foundations, earthwork, and pavements. Moisture contents and index test results are shown on the boring logs in Appendix A. The remainder of the test results is included in Appendix B.

5.1 Soils Testing

5.1.1 Index Testing

We performed natural moisture content, Atterberg Limit, and gradation tests on three samples of soil to provide soil classifications and to provide parameters for use with published correlations with soil properties. The results are presented in the Summary of Laboratory Tests in Appendix B.

5.1.2 Corrosivity Testing

We performed tests for pH, sulfides, redox potential, and resistivity testing on a soil sample representative of the upper on-site soils. The test results are presented in the table below:

Table 5.1: Soil Corrosivity

Parameter Boring No. Resistivity pH Redox Sulfide Sulfate Chloride

Unit - ohm-cm - mV ppm ppm Ppm

Value Depth (ft.)

B – 1

3.5 – 5.0

2,920 7.81 219 418 27 54

*BRL: Below Reporting Limit

These results are also presented in the Appendices, along with the various guidelines and criteria from DIPRA, AWWA, and ACI for evaluating soil corrosivity. Laboratory corrosivity testing indicates the corrosivity potential based on total cumulative soil corrosion values, per the various criteria for cast iron, steel, and concrete. Based on these test results, we anticipate the soil to have a moderate corrosive potential for underground iron pipes, buried steel structures, reinforcing steel in buried concrete, and sulfate exposure in concrete at the Barataria Preserve in Louisiana. Various techniques can be utilized to mitigate corrosion in iron and steel, including the use of cathodic protection, coating of reinforcing steel (i.e. epoxy), thickening steel members. Sulfate exposure to concrete can be mitigated by using different Type cements, reducing water-cement ratio and/or increasing compressive strength of concrete mixes to reduce permeability.

January 20, 2022 Page 6 Schnabel Engineering, LLC

6.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS

This section presents the stratigraphy and groundwater conditions encountered during our field exploration:

6.1 Generalized Subsurface Stratigraphy

We characterized the following generalized subsurface stratigraphy based on the previous and supplemental exploration and laboratory test data included in the appendices.

Table 6.1: Soil Stratigraphy

Type Test Depth (ft)

Description

STRATUM F

(Probable Fill)

Ground surface to depths of 1.5 feet

Lean Clay (CL) Very soft to soft (SPT N Value = 1 to 4 bpf)

STRATUM A

(Alluvial)

Below Stratum F to termination depths of

40.0 feet

Lean Clay (CL), Silt (ML), Silty Sand (SM) Very soft to soft and very loose (SPT N Value = Weight of Hammer to 6 bpf)

The above “N” values indicate the Standard Penetration Test resistances encountered in a particular layer as determined from the number of blows required to drive a 2-inch O.D., 1-3/8 inch I.D. sampling spoon one foot using a 140 pound hammer falling 30 inches. This test is conducted after seating the sampler six inches in the bottom of the hole according to ASTM D1586.

Soil samples have been classified in accordance with ASTM D2488. The ASTM D2488 group symbols (e.g. SM), indicated above and on the boring logs, are based on visual observations of recovered soil samples. Criteria for soil classification are given in Appendix A.

6.2 Groundwater

The test boring logs in Appendix A include groundwater observations obtained during our subsurface exploration. These data include depths to groundwater encountered during drilling and upon drilling completion.

Groundwater was encountered at approximately 11 feet below the ground surface, however, being within the wetlands area, there is standing water in much of the low-lying area surrounding the existing boardwalk. Stabilized water level was not measured during our field investigation as borings were backfilled at completion for safety.

The final design should anticipate fluctuations in the water table depending upon variations in precipitation, surface runoff, low and high tide, evaporation and similar factors.

6.3 Seismic Site Classification

We evaluated the Seismic Site Class and Seismic Site Coefficients for this project according to the International Building Code (IBC) Section 1615 (2018) and ASCE 7-16. Based on the soils and their N-values encountered in the boring and geologic history in the area, we believe the Site Class E, or a Soft Soil Profile, is applicable for this location. The value of the Maximum Considered Earthquake, MCE, Ss

January 20, 2022 Page 7 Schnabel Engineering, LLC

(%g) = 0.085 (8.5%) as a function of the site class and mapped spectral response acceleration. The mapped value of the MCE S1 (%g) = 0.051 (5.1%), which is also a function of the site class and mapped spectral response acceleration.

January 20, 2022 Page 8 Schnabel Engineering, LLC

7.0 SITE GRADING AND EARTHWORK

General recommendations for compacted fill subgrade preparation, fill soil requirements, placement and compaction criteria, are presented in subsequent sections.

7.1 Pavement Section – Gravel Trail

Gravel trails are expected to have foot traffic and the occasional Gator 4x4 Utility Vehicle.

Based on our evaluation, the gravel trails should consist of the following minimum section:

Table 7.1: Pavement Section

Dense Graded Aggregate Per LADOT Section 1003.05.01 for

Surface Courses 6 inches

Separation Type Geotextile Mirafi 140N or equal

One layer

Additional open-graded stone/gravel may be placed on this section for aesthetic purposes.

7.2 Subgrade Preparation and Compaction- Gravel Trail

Where the existing gravel surface trails are present, these materials may remain in-place. Subgrades to receive new gravel surfacing should initially be stripped of vegetation, topsoil and/or organic matter.

The Geotechnical Engineer should evaluate the suitability of the fill subgrades. The stripped subgrades should be proofrolled with light construction equipment, such as a walk-behind smooth drum roller.

Heavier compaction/construction equipment may cause additional subgrade disturbance, and is therefore not recommended. Areas that exhibit excessive pumping, weaving, or rutting should be undercut and replaced with additional crushed stone, as recommended by the Geotechnical Engineer. Subgrade evaluation techniques complementary to proofrolling could include a combination of probing with a penetrometer, drilling hand augers, or observing test pits.

It is possible that subgrade soils may be soft following stripping of vegetation, topsoil, organic matter.

Where this is the case, we recommend that the depth of aggregate stone be increased over the separation-type geotextile, rather than performing any undercutting/replacement of the soft soils. The actual depth of any additional aggregate stone would need to be determined in the field, at the time construction proceeds.

Compacted fill subgrades should be kept free of ponded water. If springs or other flowing water is present at the compacted structural fill subgrade level, the Contractor should direct water to discharge beyond the fill limits. Recommendations for discharging springs should be provided by the Geotechnical Engineer.

Compacted fill should be placed in maximum 8-inch thick horizontal, loose lifts. Fill should be compacted to the minimum dry densities as noted in the table below:

January 20, 2022 Page 9 Schnabel Engineering, LLC

Table 7.2: Compaction

Area Compaction

Requirements (per ASTM D698)

Gravel Walkways 95%

Lawn or Unimproved Areas 92%

Note that it may be necessary to use light compaction equipment, due to the possible presence of soft subgrade soils.

January 20, 2022 Page 10 Schnabel Engineering, LLC

8.0 FOUNDATION RECOMMENDATIONS

We based our geotechnical engineering recommendations on field and laboratory test data from the subsurface exploration and soil laboratory testing, along with the project plans, site plans, and structural loading furnished to our office. We believe the proposed structure would be best supported with helical piles. We considered multiple options for the design of the foundation for the boardwalk, including options such as timber piles. Timber piles and other deep foundation options would require larger and heavier equipment in which would not only require more costly and extensive preparation of the project site, but also have a larger disturbance area within the Barataria Preserve. The following sections of the report provide our detailed recommendations.

8.1 Helical Piles

We understand from the project Structural Engineer that two options are being considered for the design of the proposed boardwalk. Option one considers 10-foot spans between piles and has dead, total, and lateral loads of 8 kips, 12 kips, and 2 kips per post, respectively. Option two considers 20-foot spans between piles and has dead, total, and lateral loads of 14 kips, 22 kips, and 4 kips per post, respectively.

Based on the soft and loose silts and sands encountered across the site, we recommend helical piles be utilized for the support of the boardwalk. Helical pile capacities will depend on the length and sizes of the piles installed as well as the proprietary materials and installation procedures a helical pile contractor may use.

As two options are being considered for the boardwalk loadings, we conducted a conceptual evaluation for the helical pile preliminary designs based on Helicap design software from Chance Foundation Solutions. Using Boring B-1 and B-2 as reference for the soils encountered, we evaluated multiple designs considering a total vertical load of 12 kips and 22 kips. The design considers the top of the pile beginning at the ground surface using Round Shaft piles. We also considered a factor of safety of 2.5 for each design.

Based on our conceptual evaluation, it was determined the 20-foot spacings of the piles with a total load of 22 kips is not considered a practical design. This is due to the load being too great for the soft and loose soils encountered to have an economical design. We recommend a 10-foot spacing be used during design with a total load of 12 kips per post. The results of our preliminary analysis are provided in the following sections.

It should be noted that as the soil profile contains loose soil, the ultimate compression capacity of the Square Shaft piles (SS) may be controlled by columnar buckling of the shaft. It may be necessary to use a small diameter grout column around the SS piles, or to use Round Shaft piles (RS) instead of SS piles, as provided below.

The lateral capacity of helical piles mostly comes from the soil conditions in which they are embedded into. Since the soils encountered on site are very soft and loose, we do not expect the soil to provide any significant lateral capacity. As such, lateral loads can typically be resisted by installing helical piles on batters. The specialty contractor obtained for the design and installation of the helical piles will be able to determine the best pile shaft type and diameter.

January 20, 2022 Page 11 Schnabel Engineering, LLC

After analyzing multiple helical pile options for support of the proposed boardwalk, we narrowed the results down to three separate options. The products we have considered is the RS4500.337, RS4500.237, and RS3500.300.

Table 8.1: 12-kip Allowable Load, 10-foot Spacing

Products Pile Total Length (ft)

Helix Diameter

(in)

Helix Depth Below Ground

Surface (ft)

Installation Torque (ftꞏlb)

Nominal Helix

Strength (kips)

Incremental Ultimate

Helix Capacity

(kips)

RS4500.337 22.0

14.0 14.0 12.0

15.0 18.5 21.5

133.0 133.0 168.5

9.1 11.9 9.0

RS4500.237 22.0

14.0 14.0 12.0 10.0

12.5 16.0 19.0 21.5

133.0 133.0 168.5 200.3

7.8 10.4 8.7 6.2

RS3500.300 22.0

14.0 14.0 12.0

15.0 18.5 21.5

132.3 132.3 98.4

9.1 11.9 9.0

Based on our conceptual analyses, all three product choices above, RS4500.337, RS4500.237, and RS3500.300, will provide an ultimate axial capacity of 30 kips, 33 kips, and 30 kips, respectively.

Considering a factor of safety of 2.5, this meets the minimum criteria of 12 kips.

The piles should be designed to provide a factor of safety of at least 2.5 against ultimate loading. If a static load test is performed, the minimum factor of safety may be reduced to 2.0.

Since helical piling systems vary by manufacturer and are proprietary, we recommend this work be bid as a performance specification to helical contractors as a design/build foundation system. Schnabel Engineering should review the submittals by the selected foundation contractors licensed Geotechnical Engineer. The construction should also consist of loading testing of at least one (1) pile to provide capacity verification. Furthermore, on-site construction monitoring by a Geotechnical Engineer is considered essential to the successful complete of the project.

January 20, 2022 Page 12 Schnabel Engineering, LLC

9.0 CONSTRUCTION CONSIDERATIONS

9.1 Site Grading and Earthwork

The on-site soils are susceptible to moisture changes, will be easily disturbed, and will be difficult to compact under wet weather conditions. Drying and reworking of the soils are likely to be difficult during periods of wet months.

We expect the subgrade soils in the site to be wet and easily disturbed. The Contractor may need additional crushed stone and stabilization measures to provide for a suitable pavement surface. The Geotechnical Engineer can make recommendations for working platforms in the field, based on observation of subgrade conditions.

It should be noted that the contractor should include matting within their budget for installation equipment to be able to access the locations in which the piles will be installed. With the ground surface being extremely soft and wet, small equipment such as a skid-steer would risk the possibility of becoming stuck in the soft clay within the upper few feet.

We also recommend the contractor to install the helical piles to visit the site prior to mobilization not only due to the soil conditions, but also for observing site access as the only trails to the proposed boardwalk location are narrow.

9.2 Engineering Services During Construction

The engineering recommendations provided in this report are based on the information obtained from the subsurface exploration and laboratory testing. However, conditions on the site may vary between the discrete locations observed at the time of our subsurface exploration. The nature and extent of variations between borings may not become evident until during construction.

To account for this variability, we should provide professional observation and testing of subsurface conditions revealed during construction as an extension of our engineering services. These services will also help in evaluating the Contractor's conformance with the plans and specifications. Because of our unique position to understand the intent of the geotechnical engineering recommendations, retaining Schnabel for these services will allow us to provide consistent service throughout the project construction.

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10.0 GENERAL SPECIFICATION RECOMMENDATIONS

The conclusions and recommendations of this report are based on the information revealed by this exploration. An attempt has been made to provide for normal contingencies, but the possibility remains that unexpected conditions may be encountered during construction. An allowance should be established to account for possible additional costs that may be required to construct earthwork and foundations as recommended in this report. Additional costs may be incurred for a variety of reasons including variation of soil between borings, greater than anticipated unsuitable soils, need for borrow fill material, wet on-site soils, obstructions, temporary dewatering, etc.

The project specifications should indicate the Contractor's responsibility for providing adequate site drainage during construction. Inadequate drainage will most likely lead to disturbance of soils by construction traffic and increased volume of undercut.

This report may be made available to prospective bidders for informational purposes. We recommend that the project specifications contain the following statement:

Schnabel Engineering, LLC, has prepared this geotechnical engineering report for this project.

This report is for informational purposes only and is not part of the contract documents. The opinions expressed represent the Geotechnical Engineer’s interpretation of the subsurface conditions, tests, and the results of analyses performed. Should the data contained in this report not be adequate for the Contractor's purposes, the Contractor may make, before bidding, independent exploration, tests, and analyses. This report may be examined by bidders at the office of the Owner, or copies may be obtained from the Owner at nominal charge.

Additional data and reports prepared by others that could have an impact upon the Contractor's bid should also be made available to prospective bidders for informational purposes.

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11.0 LIMITATIONS

We based the analyses and recommendations submitted in this report on the information revealed by our exploration. We attempted to provide for normal contingencies, but the possibility remains that unexpected conditions may be encountered during construction.

This report has been prepared to aid in the evaluation of this site and to assist in the design of the project.

It is intended for use concerning this specific project. We based our recommendations on information on the site and proposed construction as described in this report. Substantial changes in loads, locations, or grades should be brought to our attention so we can modify our recommendations as needed. We would appreciate an opportunity to review the plans and specifications as they pertain to the recommendations contained in this report, and to submit our comments to you based on this review.

We have endeavored to complete the services identified herein in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same locality and under similar conditions as this project. No other representation, express or implied, is included or intended, and no warranty or guarantee is included or intended in this report or other instrument of service.

January 20, 2022 Schnabel Engineering, LLC

FIGURES

Figure 1: Test Boring Location Plan

PROJECT NUMBER

21C19034.00

FIGURE – 1

TEST BORING LOCATION PLAN

DATE

1/20/2022

RECREATIONAL USE

IMPROVEMENTS AT BARATARIA

PRESERVE, LOUISIANA

APPENDIX A

SUBSURFACE EXPLORATION DATA

Subsurface Exploration Procedures General Notes for Subsurface Exploration Logs Identification of Soil Boring Logs, B-1 and B-2

SUBSURFACE EXPLORATION PROCEDURES

Test Borings – Hollow Stem Augers

The borings are advanced by turning an auger with a center opening of 2¼ or 3¼ inches. A plug device blocks off the center opening while augers are advanced. Cuttings are brought to the surface by the auger flights. Sampling is performed through the center opening in the hollow stem auger by standard methods after removal of the plug. Usually, no water is introduced into the boring using this procedure.

Standard Penetration Test Results

The Standard Penetration Test (SPT) is performed in the borings at regular depth intervals to collect soil samples. The numbers in the Sampling Data column of the boring logs represent SPT results. Each number represents the blows needed to drive a 2-inch O.D., 1⅜-inch I.D. split-spoon sampler 6 inches, using a 140-pound hammer falling 30 inches. The sampler is typically driven a total of 18 or 24 inches.

The first 6 inches are considered a seating interval. The total of the number of blows for the second and third 6-inch intervals is the SPT “N-value.” The Standard Penetration Test is performed according to

ASTM D1586.

The SPT samples were obtained using a hydraulically driven automatic trip hammer (ATH). Most correlations with SPT data are based on N-values collected with a safety hammer. The energy applied to the split-spoon sampler using the ATH is about 33 percent greater than that applied using the safety hammer, resulting in lower N-values. The hammer blows shown on the boring logs are uncorrected for the higher energy. However, we correct SPT N-values for the higher energy when using N-values in our analyses.

Soil Classification Criteria

The group symbols on the logs represent the Unified Soil Classification System Group Symbols (ASTM D2487) based on visual observation and limited laboratory testing of the samples. Criteria for visual identification of soil samples are included in this appendix. Some variation can be expected between samples visually classified and samples classified in the laboratory.

Pocket Penetrometer Results

The values following “PP=” in the sampling data column of the logs represent pocket penetrometer readings. Pocket penetrometer readings provide an estimate of the unconfined compressive strength of fine-grained soils.

Boring Locations and Elevations

Boring locations were staked by Schnabel Engineering. Approximate boring locations are shown on Figure 1. Ground surface elevations and the boring locations were surveyed on-site by park personnel and are indicated on the boring logs. Locations and elevations should be considered no more accurate than the methods used to determine them.

GENERAL NOTES FOR

SUBSURFACE EXPLORATION LOGS

1. Numbers in sampling data column next to Standard Penetration Test (SPT) symbols indicate blows required to drive a 2-inch O.D., 1⅜-inch I.D. sampling spoon 6 inches using a 140 pound hammer falling 30 inches. The Standard Penetration Test (SPT) N-value is the number of blows required to drive the sampler 12 inches, after a 6-inch seating interval. The Standard Penetration Test is performed in general accordance with ASTM D1586.

2. Visual classification of soil is in accordance with terminology set forth in “Identification of Soil.”

The ASTM D2487 group symbols (e.g., CL) shown in the classification column are based on visual observations.

3. Estimated water levels indicated on the logs are only estimates from available data and may vary with precipitation, porosity of the soil, site topography, and other factors.

4. Refusal at the surface of rock, boulder, or other obstruction is defined as an SPT resistance of 50 blows for 1 inch or less of penetration.

5. The logs and related information depict subsurface conditions only at the specific locations and at the particular time when drilled or excavated. Soil conditions at other locations may differ from conditions occurring at these locations. Also, the passage of time may result in a change in the subsurface soil and water level conditions at the subsurface exploration location.

6. The stratification lines represent the approximate boundary between soil and rock types as obtained from the subsurface exploration. Some variation may also be expected vertically between samples taken. The soil profile, water level observations and penetration resistances presented on these logs have been made with reasonable care and accuracy and must be considered only an approximate representation of subsurface conditions to be encountered at the particular location.

7. Key to symbols and abbreviations:

S-1, SPT Sample No., Standard Penetration Test 5+10+1 Number of blows in each 6-inch increment

LL Liquid Limit MC Moisture Content (percent) PL Plastic Limit PP Pocket Penetrometer Reading (tsf) %Passing#200 Percent by weight passing a No. 200 Sieve

IDENTIFICATION OF SOIL

I. DEFINITION OF SOIL GROUP NAMES (ASTM D2487) SYMBOL GROUP NAME

Coarse-Grained Soils More than 50% retained on No. 200 sieve

Gravels – More than 50% of coarse fraction retained on No. 4 sieve Coarse, ¾” to 3” Fine, No. 4 to ¾”

Clean Gravels Less than 5% fines

GW WELL GRADED

GRAVEL

GP POORLY GRADED

GRAVEL

Gravels with fines More than 12% fines

GM SILTY GRAVEL

GC CLAYEY GRAVEL

Sands – 50% or more of coarse Fraction passes No. 4 sieve Coarse, No. 10 to No. 4 Medium, No. 40 to No. 10 Fine, No. 200 to No. 40

Clean Sands Less than 5% fines

SW WELL GRADED

SAND

SP POORLY GRADED

SAND

Sands with fines More than 12% fines

SM SILTY SAND

SC CLAYEY SAND

Fine-Grained Soils 50% or more passes the No. 200 sieve

Silts and Clays – Liquid Limit less than 50 Low to medium plasticity

Inorganic CL LEAN CLAY

ML SILT

Organic OL ORGANIC CLAY

ORGANIC SILT

Silts and Clays – Liquid Limit 50 or more Medium to high plasticity

Inorganic CH FAT CLAY

MH ELASTIC SILT

Organic OH ORGANIC CLAY

ORGANIC SILT

Highly Organic Soils Primarily organic matter, dark in color and organic odor PT PEAT

II. DEFINITION OF SOIL COMPONENT PROPORTIONS (ASTM D2487)

Examples

Adjective Form

GRAVELLY

SANDY

>30% to <50% coarse grained component in a fine-grained soil

GRAVELLY LEAN CLAY

CLAYEY

SILTY

>12% to <50% fine grained component in a coarse-grained soil

SILTY SAND

“With” WITH GRAVEL

WITH SAND

>15% to <30% coarse grained component in a fine-grained soil

FAT CLAY WITH GRAVEL

WITH GRAVEL

WITH SAND

>15% to <50% coarse grained component in a coarse-grained soil

POORLY GRADED GRAVEL WITH SAND

WITH SILT

WITH CLAY

>5% to <12% fine grained component in a coarse-grained soil

POORLY GRADED SAND WITH SILT

III. GLOSSARY OF MISCELLANEOUS TERMS

SYMBOLS .......................... Unified Soil Classification Symbols are shown above as group symbols. A dual symbol “-” indicates the soil belongs to two groups. A borderline symbol “/” indicates the soil belongs to two possible groups.

FILL ........................................ Man-made deposit containing soil, rock and often foreign matter.

PROBABLE FILL ................... Soils that contain no visually detected foreign matter but which are suspect with regard to origin.

DISINTEGRATED ROCK

(DR)

Residual materials with a standard penetration resistance (SPT) between 60 blows per foot and refusal. Refusal is defined as an SPT of 100 blows for 2" or less penetration.

PARTIALLY WEATHERED

ROCK (PWR)

Residual materials with a standard penetration resistance (SPT) between 100 blows per foot and refusal. Refusal is defined as an SPT of 100 blows for 2" or less penetration.

BOULDERS & COBBLES ...... Boulders are considered rounded pieces of rock larger than 12 inches, while cobbles range from 3 to 12-inch size.

LENSES.................................. 0 to ½-inch seam within a material in a test pit.

LAYERS ................................. ½ to 12-inch seam within a material in a test pit.

POCKET ................................. Discontinuous body within a material in a test pit.

MOISTURE CONDITIONS ...... Wet, moist or dry to indicate visual appearance of specimen.

COLOR ................................... Overall color, with modifiers such as light to dark or variation in coloration.

F

A

FILL

CL

ML

SM

ML

1.1

-0.2

-8.7

-15.7

-22.7

0.2

1.5

10.0

17.0

24.0

LL = 47

PL = 22

MC = 33.7%

% Passing #200 = 98.6 PP = 0.75 tsf PP = 1.00 tsf

PP = 0.75 tsf

PP = 1.25 tsf

LL = 35

PL = 28

MC = 40.1%

% Passing #200 = 97.2 PP = 0.00 tsf

LL = NP

MC = 30.1%

% Passing #200 = 40.9

PP = 0.00 tsf

S-01, SPT

2+2+2

S-02, SPT

1+3+2

S-03, SPT

WOH+2+1

S-04, SPT

WOH/12"+1

S-05, SPT

1+1+WOH

S-06, SPT

WOH/12"+2

S-07, SPT

WOH/12"+1

Topsoil

PROBABLE FILL, sampled as lean clay;

moist, grayish brown, trace shell fragments

LEAN CLAY; moist, bluish gray, probable ALLUVIAL material

Change: trace gravel, trace sand

SILT; wet, bluish gray

Change: wet

SILTY SAND, fine grained sand; wet, gray

SILT; wet, gray

Encountered

Completion

11/23

11/23

11.5'

12.0'

Schnabel Representative: K. Morgan

Total Depth: 30.0 ft

Equipment: Geoprobe 7822DT

Ground Surface Elevation: 1.3 (ft)

Contractor: PSI, Inc.

Jefferson, Louisiana

Contractor Foreman: C. Baker

Hammer Type: Auto Hammer (140 lb)

Dates Started: 11/23/21 Finished: 11/23/21

Latitude: 29.78847 Longitude: -90.10637 By: Estimated from topo map

Method: 4-1/4" I.D. Hollow Stem Auger

Plunge: Bearing:

Date CavedDepthTime Casing Groundwater Observations

Project:

STRA

TUM

Recreational Use Improvements at Barataria Preserve Marreo, Louisiana

SYMBOL

Contract Number: 21C19034.00 Sheet: 1 of 2

ELEV

(ft)

TEST

BORING

LOG

TESTS

DATA

MATERIAL DESCRIPTION

SAMPLING

DEPTH

REMARKS

B-1Boring Number:

DEPTH

(ft)

T E

S T

B O

R

IN

G L

O G

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

(continued)

ML

SM

ML

-26.2

-28.2 -28.7

27.5

29.5 30.0

S-08, SPT

WOH/18"

SILT; wet, gray (continued)

SILTY SAND, fine grained sand; wet, gray

SILT; wet, gray

Bottom of Boring at 30.0 ft.

Auger refusal at 30.0 ft.

Boring terminated at auger refusal.

Boring backfilled with cuttings upon completion.

Boring terminated at 30 ft. due to heaving sands in bottom of auger.

Project:

STRA

TUM

Recreational Use Improvements at Barataria Preserve Marreo, Louisiana

SYMBOL

Contract Number: 21C19034.00 Sheet: 2 of 2

ELEV

(ft)

TEST

BORING

LOG

TESTS

DATA

MATERIAL DESCRIPTION

SAMPLING

DEPTH

REMARKS

B-1Boring Number:

DEPTH

(ft)

T E

S T

B O

R

IN

G L

O G

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

F

FILL

CL

ML

SM

ML

1.0

-0.3

-7.8

-17.8

-22.8

0.2

1.5

9.0

19.0

24.0

S-01, SPT

WOH/12"+1

S-02, SPT

1+1+3

S-03, SPT

1+1+2

S-04, SPT

WOH+2+1

S-05, SPT

WOH+1+1

S-06, SPT

WOH/12"+2

S-07, SPT

1+1+2

Topsoil

PROBABLE FILL, sampled as lean clay;

moist, grayish brown, trace shell fragments

LEAN CLAY; moist, bluish gray, probable ALLUVIAL material

Change: trace gravel, trace sand

SILT; wet, bluish gray

Change: wet

SILTY SAND, fine grained sand; wet, gray

SILT; wet, gray

Encountered

Completion

11/30

11/30

11.0'

11.5'

Schnabel Representative: K. Morgan

Total Depth: 40.0 ft

Equipment: Geoprobe 7822DT

Ground Surface Elevation: 1.2 (ft)

Contractor: PSI, Inc.

Jefferson, Louisiana

Contractor Foreman: C. Baker

Hammer Type: Auto Hammer (140 lb)

Dates Started: 11/30/21 Finished: 11/30/21

Latitude: 29.78897 Longitude: -90.10631 By: Estimated from topo map

Method: 4-1/4" I.D. Hollow Stem Auger

Plunge: Bearing:

Date CavedDepthTime Casing Groundwater Observations

Project:

STRA

TUM

Recreational Use Improvements at Barataria Preserve Marreo, Louisiana

SYMBOL

Contract Number: 21C19034.00 Sheet: 1 of 2

ELEV

(ft)

TEST

BORING

LOG

TESTS

DATA

MATERIAL DESCRIPTION

SAMPLING

DEPTH

REMARKS

B-2Boring Number:

DEPTH

(ft)

T E

S T

B O

R

IN

G L

O G

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

(continued)

ML

SM

ML

-26.8

-28.8

-38.8

28.0

30.0

40.0

S-08, SPT

2+1+3

S-09, SPT

1+2+3

S-10, SPT

3+3+3

SILT; wet, gray (continued)

SILTY SAND, fine grained sand; wet, gray

SILT; wet, gray

Bottom of Boring at 40.0 ft.

Boring terminated at selected depth.

Boring backfilled with cuttings upon completion.

Project:

STRA

TUM

Recreational Use Improvements at Barataria Preserve Marreo, Louisiana

SYMBOL

Contract Number: 21C19034.00 Sheet: 2 of 2

ELEV

(ft)

TEST

BORING

LOG

TESTS

DATA

MATERIAL DESCRIPTION

SAMPLING

DEPTH

REMARKS

B-2Boring Number:

DEPTH

(ft)

T E

S T

B O

R

IN

G L

O G

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

APPENDIX B

SOIL LABORATORY TEST DATA

Summary of Laboratory Tests Gradation Curves

B-1

1.0 - 2.5

0.3 - -1.2

SPT

LEAN CLAY (CL), bluish gray

A 33.7 47 22 25 0.0 98.6

B-1

13.5 - 15.0

-12.2 - -13.7

SPT

SILT (ML), bluish gray

A 40.1 35 28 7 0.0 97.2

B-1

18.5 - 20.0

-17.2 - -18.7

SPT

SILTY SAND (SM), gray

A 30.1 NP NP NP 0.0 40.9

Description of Soil Specimen

Project Number: 21C19034.00

Notes:

Project:

Sample Depth ft

Elevation ft

Recreational Use Improvements at Barataria Preserve Marreo, LA

Sample Type

Sheet 1 of 1

Boring No.

Summary Of Laboratory Tests Appendix

1. Soil tests in general accordance with ASTM standards.

2. Soil classifications are in general accordance with ASTM D2487(as applicable), based on testing indicated and visual classification.

3. Key to abbreviations: NP=Non-Plastic; -- indicates no test performed.

4. ASTM Methods: Natural Moisture D2216, Atterberg D4318, Gradation D6913

D Y

N A

M

IC

L A

B S

U M

M A

R Y

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

P la st ic it y

In d ex

R et ai n ed

N o

S ie ve

S tr at u m

P la st ic

L im it

L iq u id

L im it

P as si n g

N o

S ie ve

N at u ra l M o is tu re

0.0010.010.1110100

16 4 3

GRAIN SIZE IN MILLIMETERS

Test Method

1.4

%Silt %Clay

ASTM D6913

PI

D10 %Gravel

0.0

%Sand

98.6

D30

Sample Description

B-1 2522

D100 D60

LEAN CLAY (CL), bluish gray

Specimen LL PL

SRHMDE

Tested Date

MDE

Tested By

11/30/21

Calc by

U.S. SIEVE OPENING IN INCHES

41.5 6

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

100 14060

Percent Finer

4.75

U.S. SIEVE NUMBERS

501/23/8 4023 3/4

HYDROMETER

GRADATION CURVE

16 20 30

Test Method

Atterberg

ASTM D4318

Reviewed by

1.0 - 2.5 ft

Project: Recreational Use Improvements at Barataria Preserve Marreo, LA

Contract: 21C19034.00S

IE

V E

/S

H E

E T

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

1 fine coarse

COBBLES SILT OR CLAY

medium fine

SANDGRAVEL

coarse

Sieve Size

% Finer

98.6

100.0

0.0010.010.1110100

16 4 3

GRAIN SIZE IN MILLIMETERS

Test Method

2.8

%Silt %Clay

ASTM D6913

PI

D10 %Gravel

0.0

%Sand

97.2

D30

Sample Description

B-1 728

D100 D60

SILT (ML), bluish gray

Specimen LL PL

SRHMDE

Tested Date

MDE

Tested By

11/30/21

41.5 6

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

100 14060

Percent Finer

0.85

U.S. SIEVE NUMBERS

501/23/8 4023 3/4

HYDROMETER

GRADATION CURVE

16 20 30

Test Method

Atterberg

ASTM D4318

Reviewed by

13.5 - 15.0 ft

Project: Recreational Use Improvements at Barataria Preserve Marreo, LA

Contract: 21C19034.00S

IE

V E

/S

H E

E T

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

1 fine coarse

COBBLES SILT OR CLAY

medium fine

SANDGRAVEL

coarse

Sieve Size

% Finer

97.2

99.8

99.8

99.9

99.9

100.0

100.0

0.0010.010.1110100

16 4 3

GRAIN SIZE IN MILLIMETERS

Test Method

59.1

%Silt %Clay

ASTM D6913

PI

0.094

D10 %Gravel

0.0

%Sand

40.9

D30

Sample Description

B-1 NPNP

D100 D60

SILTY SAND (SM), gray

NP

Specimen LL PL

SRHMDE

Tested Date

MDE

Tested By

11/30/21

41.5 6

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

100 14060

Percent Finer

0.425

U.S. SIEVE NUMBERS

501/23/8 4023 3/4

HYDROMETER

GRADATION CURVE

16 20 30

Test Method

Atterberg

ASTM D4318

Reviewed by

18.5 - 20.0 ft

Project: Recreational Use Improvements at Barataria Preserve Marreo, LA

Contract: 21C19034.00S

IE

V E

/S

H E

E T

B A

R A

T A

R

IA

P R

E S

E R

V E

B O

R

IN

G L

O G

S .G

P J

T E

S T

T E

M P

LA

T

E .G

D T

2/

8/

1 fine coarse

COBBLES SILT OR CLAY

medium fine

SANDGRAVEL

coarse

Sieve Size

% Finer

40.9

98.8

99.7

100.0

100.0

100.0

100.0

SOIL MECHANICS LABORATORY

CORROSION POTENTIAL SERIES

Project Name:

Location:

Project No:

Sample No:

Depth (ft):

Classification:

Test Unit

Resistivity ohm-cm pH --

Redox mV

Sulfide ppm

Moisture condition

Sulfate ppm

Chloride ppm

Soil Description --

Notes:

1. See attached Tables for point system information and data interpretation

2. BRL = Below Reporting Limit

Set up by: MDE MDE Checked by: SH Date: 1/5/22 1/5/22 Date: 1/7/2021

LEAN CLAY (CL), bluish gray

Clay -- 3

NACE Guidelines Points

--Moist

AWWA Guidelines Points

Bataria Preserve New Orleans, LA 21C19035.00

B-1

3.5-5.0'

3.5

2,920

Readings

7.81

Tested by:

Date:

9Total Points 5.5

Soil Mechanics Laboratory Corrosion Potential Series

Table 1: AWWA Guidelines. AWWA C-105, 10-pt soil test evaluation for iron pipe

Soil Characteristics Points

Resistivity (Ω-cm)1 < 1,500 10

≥1,500-1,800 8 >1,800 – 2,100 5 >2,100-2,500 2 >2,500-3,000 1

> 3,000 0 pH

0 – 2 5

2.01 – 4.00 3

4.01 – 6.5 0

6.51 – 7.5 0*

7.51 – 8.5 0

> 8.5 3 Redox potential (mV)

> +100 0 +50 to +100 3.5

0 to +50 4 < 0 5

Sulfides Positive 3.5 Trace 2

Negative 0 Moisture

Wet 2 Moist 1 Dry 0

* If sulfides are present and a low (<100mV) or negative redox result is obtained, three points shall be given for this pH range.

1 Based on water-saturated soil box. This method is designed to obtain the lowest and most accurate resistivity reading.

NOTE: If total cumulative points ≥ 10, the tested soil has potential for corrosion, according to the AWWA Guidelines.

Table 2: ACI 318 Guidelines-Requirements for concrete exposed to sulfate-containing solutions

* When both Table 4.3.1 and Table 4.2.2 are considered, the lowest applicable maximum water-cementitious material ratio and highest applicable minimum fc′ shall be used.

1 Seawater.

2 Pozzolan that has been determined by test or service record to improve sulfate resistance when used in concrete containing Type V cement.

Table 3: NACE Guidelines. Adapted from Table 20.1 “Assessment of Overall Soil Corrosivity to Steel”, C.P. Dillon Corrosion Control in the Chemical Process Industries.

Sulfate exposure

Water soluble Sulfate (SO4) in soil, percent by weight

Sulfate (SO4) in water, ppm

Cement type

Maximum water-cementitious material ratio, by weight, normal weight concrete*

Minimum fc′, normal-weight and lightweight concrete, psi*

Negligible 0.00 ≤ SO4 < 0.10 0 ≤ SO4 < 150 — — —

Moderate1 0.10 ≤ SO4 < 0.20 150 ≤ SO4 < 1500

II, IP(MS),

IS(MS),

P(MS),

I(PM)(MS),

I(SM)(MS)

0.50

Severe 0.20 ≤ SO4 ≤ 2.00 1500 ≤ SO4 ≤ 10,000 V 0.45 4500

Very severe

SO4 > 2.00 SO4 > 10,000

V plus pozzolan2 0.45 4500

ANALYSIS

TYPE

ANALYSIS

RANGE

POINTS

ANALYSIS

TYPE

ANALYSIS

RANGE

POINTS

pH

0 – 2 5

Soil Description

Clay (Blue-Gray) 10

2 – 4 3 Clay/Stone 5

4 – 8.5 0 Clay 3

> 8.5 3 Silt 2

Chloride Content

> 1000 ppm 10 Clean Sand 0

500 – 1000 ppm 6 --- --

200 – 500 ppm 4

Soil Resistivity

< 1,000 ohm-cm 10

50 – 200 ppm 2 1,000 – 1,500 ohm-cm 8 0 – 50 ppm 0 1,500 – 2,500 ohm-cm 6

Redox Potential

Negative 5 2,500 – 5,000 ohm-cm 4 0 – 100 mV 4 5,000 – 10,000 ohm-cm 2

> 100 mV 0 > 10,000 ohm-cm 0

SOIL CORROSIVITY TOTAL POINTS

Severe 15.5 Appreciable 10.0 – 15.5

Moderate 5.0 – 9.5 Mild 0 – 4.5