MEG_Geotechnical_Report_No._01-23-29170.pdf

Report On: Geotechnical Engineering Report Submittal

City of Edinburg Mardoqueo Hinojosa 415 W. University Edinburg, TX 78539

Client:

Location: Edinburg, Hidalgo County, TX Report Date:

Sampled By:

City of Edinburg Municipal Park Baseball Fields

Project:

Project No: 01-23-29170

Sample Date:

Leticia Puentes

01/26/2024

01/26/2024

Acct. No.: Edinburg123

Lab No:

Report No:

35093 1-1

Area Offices

TBPE FIRM No. F-3913 www.megengineers.com

956-702-8500 956-454-8832 956-568-1664

5804 N. Gumwood Ave.

1221 E. Tyler Ave.

5918 McPherson Rd., Ste. 5

Pharr, Texas 78577 Harlingen, Texas 78550 Laredo, Texas 78041

We are pleased to submit the attached geotechnical engineering report for the City of Edinburg Municipal Park Baseball Fields Turf in Edinburg, Hidalgo County, TX. Please redistribute attached report as necessary. MEG appreciates your business and looks forward to continue working with you on upcoming projects. We emphasize that our report be reviewed to its fullest, and to arrange a conference call with one of our engineers for any questions about the report.

Remarks:

01/26/2024

Respectfully Submitted, Millennium Engineers Group, Inc.

Raul Palma, P.E.

REPORT CREATED BY ElmTree SYSTEM NOTED. THESE REPORTS ARE FOR THE EXCLUSIVE USE OF THE ADDRESSED CLIENT AND ARE NOT TO BE REPRODUCED WITHOUT WRITTEN PERMISSION.

THE QUALITIES OF APPARENTLY IDENTICAL OR SIMILAR PRODUCTS OR PROCEDURES, NOR DO THEY REPRESENT AN ONGOING QUALITY ASSURANCE PROGRAM UNLESS SO THIS REPORT APPLIES ONLY TO THE STANDARDS OR PROCEDURES INDICATED AND TO THE SAMPLE(S) TESTED AND/OR OBSERVED AND ARE NOT NECESSARILY INDICATIVE OF

Geotechnical Engineering • Construction Materials Engineering & Testing Environmental • Consulting • Forensics

MEG GEOTECHNICAL ENGINEERING REPORT

PROPOSED

CITY OF EDINBURG MUNICIPAL PARK

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

MILLENNIUM ENGINEERS GROUP, INC.

TBPE FIRM NO. F-3913

5804 N. GUMWOOD AVENUE

PHARR, TEXAS 78577

TEL:956-702-8500

FAX:956-702-8140

WWW.MEGENGINEERS.COM

GEOTECHNICAL ENGINEERING REPORT

FOUNDATION RECOMMENDATIONS

PROPOSED CITY OF EDINBURG MUNICIPAL PARK

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

Prepared For

Mr. Mardoqueo Hinojosa, P.E., CFM, CPM City of Edinburg

MEG Report No. 01-21-29235

January 26, 2024

Millennium Engineers Group, Inc.

5804 N. Gumwood Avenue Pharr, Texas 78577 www.megengineers.com Tel:956-702-8500 Fax:956-702-8140

MEG Project No.: 01-23-29170 Page II

Mardoqueo Hinojosa, P.E., CFM, CPM City Engineer City of Edinburg 415 W. University Drive Edinburg, TX 78541 (956)388-8955 mhinojosa@cityofedinburg.com

Subject: Geotechnical Engineering Report MEG Report No. 01-23-29170 Foundation Recommendations Proposed City of Edinburg Municipal Park Baseball Fields Turf Edinburg, Hidalgo County, Texas

Dear Mr. Hinojosa (CLIENT):

Millennium Engineers Group, Inc. is pleased to submit the enclosed geotechnical engineering report that was prepared for the above subject project. This report addresses the procedures and findings of our geotechnical engineering study. Our recommendations should be incorporated into the design and construction documents for the proposed development.

We want to emphasize the importance that all our recommendations presented in this report and/or addendums to this report be followed. We look forward to continuing our involvement in the project by providing construction monitoring in accordance with the report recommendations and materials testing services during construction. We strongly recommend that we be a part of the preconstruction meeting to address any specific issues that are pertinent to this project.

Thank you for the opportunity to be of service to you in this phase of the project and we would like the opportunity to assist you in the upcoming phases of the project. If you have any questions, please contact our office at the address, telephone, fax or electronic address listed below.

Amos Emerson, P.E.

Geotechnical Engineering Department

Cordially, Millennium Engineers Group, Inc.

TBPE Firm No. F-3913

Quyet Thang Pham, Ph.D., P.E.

Geotechnical Engineer

The seal appearing on this document was authorized by Quyet Thang Pham, P.E. 131836 on January 26, 2024.

Alteration of a sealed document without proper notification to the responsible engineer is an offence under the Texas Engineering Practice Act

Cc: 1 Original and PDF Document

Amos Emerson P E

TBPEPPPPP Firm No. F-3913

Q t Th Ph Ph

Geotechnical Engineering Report

Millennium Engineers Group, Inc.

5804 N. Gumwood Avenue Pharr, Texas 78577 www.megengineers.com Tel:956-702-8500 Fax:956-702-8140

Page III

TABLE OF CONTENTS

Page

5.3

6.0

6.1 General

6.2

6.3 Plasticity Index Testing

7.0

7.1 General

7 -Related Movements 7.3 7.4

7.5 Trench Drain

7.6 Drainage

8.4 Recommendations

8.5 8.6 8.7

8.8 Utility Trench Recommendations

8.9

APPENDIX

D - E -

MEG Page 1 of 14

1.0 INTRODUCTION

Millennium Engineers Group, Inc. (MEG) has completed and is pleased to submit this document that presents our findings as a result of a geotechnical engineering study of this project to our client. The project site is at 714 S. Raul Longoria in Edinburg, Hidalgo County, Texas. The project location is shown on the Project Location Map, found in the Appendix section of this report. This report briefly describes the procedures utilized during this study and presents our findings along with our recommendation, for foundation design and construction considerations.

Our scope of services for the project was outlined in MEG proposal No. 01-23-210G, dated October 20, 2023, and approved by Mr. Mardoqueo Hinojosa on October 20, 2023.

2.0 PROJECT DESCRIPTION

It is our understanding that the proposed site will accommodate the construction of a new synthetic field turf for an six (6) existing baseball fields. The site construction for the proposed field is anticipated to be synthetic turf provided expansive, soil-related movements will not impair the performance of the field.

3.0 SCOPE AND LIMITATIONS OF STUDY

This engineering report has been prepared in accordance with accepted geotechnical engineering practices currently exercised by geotechnical engineers in this area. No warranty, expressed or implied, is made or intended. This report is intended for the exclusive use by the client and client’s authorized project team for use in preparing design and construction documents for this project only. This report may only be reproduced in its entirety for inclusion in construction documents. This report in its entirety shall not be reproduced or used for any other purposes without the written consent of our firm. This report may not contain sufficient information for purposes of other parties or other uses and is not intended for use in determining construction means and methods.

The recommendations presented in this report are based on data obtained from the soil borings drilled at this site and our understanding of the project information provided to us by our client and other project team members, and the assumption that site grading will result in only minor changes in the existing topography. Subsurface soil conditions have been observed and interpreted at the boring locations only.

This report may not reflect the actual variations of the subsurface conditions across the subject site. It is important to understand that variations may occur due to real geologic conditions or previous uses of the site. The nature and extent of variations across the subject site may not become evident until specific design locations are identified and/or construction commences. The construction process itself may also alter subsurface conditions. If variations appear evident at the time during the design phase and/or construction phase, we should be notified immediately to determine if our opinions, conclusions and recommendations need to be reevaluated. It may be necessary to perform additional field and laboratory tests and engineering analyses to establish the

MEG Page 2 of 14 engineering impact of such variations. These services are additional and are not a part of our project scope.

The engineering report was conducted for the proposed project site described in this report. The conclusions and recommendations contained in this report are not valid for any other project sites. If the project information described in this report is incorrect, is altered, or if new information becomes available, we should be retained to review and modify our recommendations. These services are additional and are not a part of our project scope.

Our scope of services was limited to the proposed work described in this report, and did not address other items or areas. The scope of our geotechnical engineering study does not include environmental assessment of the air, soil, rock or water conditions on or adjacent to the site. No environmental opinions are presented in this report. If the client is concerned with environmental risk at this project site, the client should perform an environmental site assessment.

If final grade elevations are significantly different from existing grades at the time of our field activities (more than plus or minus one (1) foot), our office should be informed about these changes. If desired, we will reexamine our analyses and make supplemental recommendations.

4.0 FIELD EXPLORATION PROCEDURES

Subsurface conditions at the subject site were evaluated by six (6) 15-foot soil borings.

The Borings were drilled at the locations shown on the Borings Location Map, found in the Appendix section of this report. This location is approximate and distances were measured using a measuring wheel, tape, angles, and/or pacing from existing references.

The structural soil borings were drilled in general accordance with American Society of Testing Materials (ASTM) D 420 procedures.

As part of our sampling procedures, the samples were collected in general conformance with ASTM D 1586 procedures. Representative portions of the samples were sealed in containers to reduce moisture loss, identified, packaged, and transported to our laboratory for subsequent testing. In the laboratory, each sample was evaluated and visually classified by a member of our Geotechnical Engineering staff. The geotechnical engineering properties of the strata were evaluated by a series of laboratory tests. The results of the laboratory and field-testing are tabulated on the boring logs and Summary of Soil Sample Analyses which are found in the Attachments section of this report.

Standard penetration test results are noted on the boring logs as blows per 12 inches of penetration. Three 6 inch increments are performed for each standard penetration test.

The sum of the blows for the final two 6 inch increments is considered the “standard penetration resistance value” or “N-value.” Where hard or very dense materials were encountered, the tests are terminated as follows: (1) when a total of 50 blows have been applied in any of the 6 inch increments, or (2) when a total of 100 blows have been applied, or (3) when there is no observed advance of the sampler in the application of 10 successive blows. The boring logs in the case of hard or very dense materials will be

MEG Page 3 of 14 noted as follows: 50/3”, where 50 is the number of blows applied in 3 inches of penetration, or 100/7½” where 100 is the number of blows applied in a total of 7 ½ inches of penetration, or 10/0”, where 10 is the number of blows applied in 0 inches of penetration.

Samples will be retained in our laboratory for 30 days after submittal of this report. Other arrangements may be provided at the request of the Client.

5.0 GENERAL SITE CONDITIONS

5.1 Site Description

The project site is at 714 S. Raul Longoria in Edinburg, Hidalgo County, Texas. The project location is shown on the Project Location Map, found in the Appendix section of this report. At the time of our field operations, the subject site can be described as a developed tract of land with an existing stadium. The general topography of the site is relatively flat sloping down to the east with a visually estimated vertical relief of less than 3 feet. Surface drainage is visually estimated to be poor to fair.

5.2 Site Geology

According to the Soil Survey of Hidalgo County, Texas, published by the United States Department of Agriculture – Soil Conservation Service, the project site appears to be located within Hidalgo soil association.

The Hidalgo series consist of deep, well drained, loamy soils and nearly level soils that are on convex uplands. These soils formed in calcareous loamy and clayey sediments. This soil is well drained, surface runoff is slow and permeability is moderate. The hazards of water erosion and soil blowing are slight. Slopes range from 0 to 5 percent. Areas are mostly broad and irregular in shape and range from 25 to more than 900 acres or more. The corresponding soil symbol is 28, Hidalgo sandy clay loam.

5.3 Subsurface Conditions

On the basis of our borings, four (4) generalized strata that possess similar physical and engineering characteristics can describe the subsurface stratigraphy at this site. Table

5.1 summarizes the approximate strata range in our boring logs. These were prepared by visual classification and were aided by laboratory analyses of selected soil samples.

The lines designating the interfaces between strata on the boring logs represent approximate boundaries. Transitions between strata may be gradual details for each of the borings can be found on the boring logs in the appendix of this report.

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Table 5.1. Approximate Subsurface Stratigraphy Depths.

Stratum Range in Depth, ft1 Stratum Description1

I2 0 – 6 lean CLAY w/ sand to sandy lean CLAY, brown, dry to moist, soft to stiff

II2 6 – 15 fat CLAY to fat CLAY w/ sand, brown, dry to moist, med. stiff to very stiff

III3 0 – 8 lean CLAY w/ sand to sandy lean CLAY, brown, moist, soft to stiff

VI3 8 – 15 fat CLAY, brown, dry to moist, med. stiff to very stiff

Note 1: The stratum thickness and depths to strata interfaces are approximate. Our measurements are rounded off to the nearest foot increment and are referenced from ground surface at the time of our drilling activities. Subsurface conditions may vary between the boring locations.

Note 2: Stratum I & Stratum II were only encountered in bores: B-1, B-2, & B-3.

Note 3: Stratum III & Stratum IV were only encountered in bores: B-4, B-5, & B-6.

5.4 Groundwater Conditions

The dry auger drilling technique was used to complete the soil borings in an attempt to observe the presence of subsurface water. During our drilling operations we did not encounter the groundwater table. Moisture content test exhibited high moisture content at a depth of six (6) feet below natural ground elevation. Table 5.2 summarizes the approximate groundwater and cave in depths measured in our explorations. It should be noted that the groundwater level measurements recorded are accurate only for the specific dates on which measurement were obtained and does not show fluctuations throughout the year.

Fluctuations in Groundwater levels are influenced by variations in rainfall and surface water run-off from season to season. The construction process itself may also cause variations in the groundwater level. If the subsurface water elevation is critical to the construction process the contractor should check the subsurface water conditions just prior to construction excavation activities.

Table 5.2. Approximate Groundwater and Cave-in Depths.

Boring No.

Depth to Subsurface Water, Ft1 Depth to Cave-In, Ft1

Time of Drilling Time of Drilling B-1 None None B-2 None None B-3 None None B-4 None None B-5 None None B-6 None None

Note 1: Subsurface water levels and cave-in depths have been rounded to the nearest foot.

MEG Page 5 of 14

Based on the findings in our borings and on our experience in this region, we believe that groundwater seepage may not be encountered during site earthwork activities. If groundwater seepage is encountered during site earthwork activities, it may be controlled using temporary earthen berms and/or conventional sump-and-pump dewatering methods.

6.0 LABORATORY TESTING ANALYSIS

6.1 General

The analyses presented in this report are applicable specifically to the proposed project for the purpose of pre-design project evaluation. The recommendations made in this report are not intended to provide final design criteria for foundations and pavement design. The data gathered from both the field and laboratory testing programs on soil samples obtained from the borings was utilized to establish geotechnical engineering parameters for the proposed project.

6.2 Moisture Content Testing

The moisture content of a soil is defined as the ratio of the weight of the water in the sample to the dry weight of the soil sample expressed as a percentage. The moisture contents for the samples obtained as part of our geotechnical study were performed in accordance with ASTM D2216. The results varied from fourteen (14) percent to twenty-seven (27) percent. The borings and corresponding soil samples exhibited moist to wet soil conditions. A list of all the moisture contents by corresponding depth can be found on the boring log.

6.3 Plasticity Index Testing

The Plasticity Index (PI) is known as the difference between the liquid limit and the plastic limit of a soil. These limits are commonly referred to as the Atterberg limits, which describe the consistency of soils with respect to their varying moisture contents. The liquid limit is defined as the moisture content at which soil begins to transition from a plastic to a liquid state, and begins to behave as a liquid material. The plastic limit refers to the water content of a soil at the point of transition from a semisolid to a plastic state where soil starts to exhibit plastic behavior. The plasticity index testing performed in accordance with ASTM D4318 shows the range in which a soil acts in a plastic state.

Plasticity Index values for the soil’s samples performed for this report were found to have a value of twenty-one (21) percent to forty-seven (47) percent having a moderate to high plasticity.

6.4 Particle Size Analysis Testing (Determination of Fines Content)

Standard grain size analysis is used to determine the relative proportions of different grain sizes as they are distributed along a range of different sized sieves. The minus 200 sieve analysis is used commonly as a tool for soil classification and identification using the Unified Soil Classification System. Results for this test are reported as a percentage of soil passing the No. 200 sieve, which has openings 0.075mm wide. This test is also used

MEG Page 6 of 14 to determine the suitability of soil for construction purposes and to estimate probable seepage through soils. Generally, a %- 200 greater than 50% indicates a cohesive soil with large amounts of fine sized grains in the soil composition having low seepage potential. Sieve analysis testing was performed in accordance with ASTM D1140. The % -200 soil values for the samples collected ranged from 62% passing to 90% passing (cohesive fine-grained materials such as fat clays).

7.0 ENGINEERING ANALYSIS AND RECOMMENDATIONS

7.1 General

The analysis and recommendations presented in this report are applicable specifically to the proposed foundation structure. The data gathered from both the field and laboratory testing programs on soil samples obtained from the borings was utilized to establish geotechnical engineering parameters to develop recommendations for the proposed structure. The foundation system(s) considered in this report to provide support for the proposed structure must meet two independent criteria. One of the criteria is that the movement below the foundation structure due to compression (consolidation) or expansion (swell) of the underlying soils must be within tolerable limits. This criterion is addressed in the Soil Related Movements section of this report. The other criterion is that the dead and live loads must be distributed appropriately and the foundation structure designed with an acceptable factor of safety to minimize the potential for bearing capacity failure of the underlying soils.

Geotechnical and structural engineers in this general area consider soil movements or Potential Vertical Rise (PVR) of approximately one (1) inch or less to be within acceptable structural design tolerances for most structures but may be different depending on structure use and the desired performance of the foundation. Therefore, movements of the underlying soils are not eliminated and thus one should expect a slab foundation structure to exhibit differential vertical movements. However, structural engineers design slab foundations for the expected magnitude of soil movements without failure of the structure. More stringent soil movement criteria may be established but the owner should consider the exponential increase in cost required to design and construct a structure for such soil movements. Data obtained in this study indicate that the soils at this site have strength characteristics capable of supporting the foundation and structure if designed appropriately. Stratum I is composed of sandy lean clay and has a moderate potential to exhibit volumetric changes (contraction and expansion). Stratum II is composed of fat clay with sand and has a high potential to exhibit volumetric changes. The potential for soil volumetric changes is dependent on variations in moisture contents of the underlying soils. Based on this data, this site is suitable for a slab foundation provided the subgrade is modified in accordance with the recommendations established in this report to reduce the potential for these soil volumetric changes.

7.2 Soil-Related Movements

The anticipated ground movements due to swelling of the underlying soils at this site were estimated for slab foundation construction using the Texas Department of Transportation (TxDOT) procedures of test method TEX-124-E for determining Potential Vertical Rise

MEG Page 7 of 14

(PVR). A PVR value of two and a half (2 ½) inches was estimated for the stratigraphic conditions encountered in our subsurface borings. A surcharge of 1 pound per square inch for the concrete slab, an active zone of 15 feet, and dry subsurface moisture conditions were assumed in estimating the above PVR values.

The following methods are generally acceptable for use in modifying the subgrade to reduce the potential for soil movements and volumetric changes below the foundation structure.

Excavate expansive clay soils and replace with select fill.

Chemical injection of expansive clay soils.

A combination of methods 1 and 2.

The method to be used is dependent on specific site conditions. At this site, the existing baseball field grade will be the proposed Finished Floor Elevation (FFE).

Based on the data obtained, the proposed FFE of existing natural ground elevation, information provided by our client and our analysis of the site, we recommend the following modification (Table 6.1. Subgrade Modifications) of the subgrade at this area to accomplished finish floor elevation of the subgrade at this site. This method will maintain the potential for soil related movements to an approximate PVR value of one and a half (1 ½) inches, which is recommended by the installer of this project.

Table 7.1.a. Subgrade Modifications (PVR of 1 inch) Item Description

1 See and adhere to the Site Preparation Recommendations section of this report.

Excavate existing soils to the recommended depth below natural ground elevation as per the installer of SG3-Vertex-65 synthetic grass – silt-film/monofilament 2.5” in accordance with the Site Preparation Recommendations section of this report.

Condition and compact twelve (12) inches of subgrade treated with 5 ½% lime below excavated soils in accordance with the Lime Treated Subgrade Recommendations section of this report.

Place select fill, (a total of one (1) foot select fill) condition and compact in accordance with the Select Fill Recommendations section of this report.

Place an Aggregate Base Course, (a minimum of eight (8) inches) condition and compact to a minimum 98% compaction up to the proposed FFE in accordance with the Select Fill Recommendations section of this report.

MEG Page 8 of 14

Table 7.1.b. Subgrade Modifications (PVR of 1 ½ inches) Item Description

1 See and adhere to the Site Preparation Recommendations section of this report.

Excavate existing soils to the recommended depth below natural ground elevation as per the installer of SG3-Vertex-65 synthetic grass – silt-film/monofilament 2.5” in accordance with the Site Preparation Recommendations section of this report.

Condition and compact twelve (12) inches of subgrade treated with 5 ½% lime below excavated soils in accordance with the Lime Treated Subgrade Recommendations section of this report.

Place an Aggregate Base Course, (a minimum of six (6) inches) condition and compact to a minimum 98% compaction up to the proposed FFE in accordance with the Select Fill Recommendations section of this report.

The PVR method of estimating expansive, soil-related movements is based on empirical correlations utilizing the measured plasticity indices and assuming typical seasonal fluctuations in moisture content. If desired, other methods of estimating expansive, soil-related movements are available, such as estimations based on swell tests and/or soil-suction analyses. However, the performance of these tests and the detailed analyses of expansive, soil-related movements were beyond the scope of the current study. It should also be noted that actual movements can exceed the calculated PVR values as a result of isolated changes in moisture content (such as leaks, landscape watering, etc.) or if water seeps into the soils to greater depths than the assumed active zone depth due to deep trenching and/or excavations.

7.3 Synthetic Turf

An important factor in the design of synthetic turf surfaces is positive drainage of surface water from the field. Also, we assumed that the synthetic turf surface will need to support periodic passes by loaded maintenance equipment and vehicles. In general, the site conditions are adequate to support anticipated loads. We recommend excavating the upper soil layer which is composed of lean clays observed in our borings and replacing it with a structural fill for the purpose of improving drainage mitigating soil swell and shrink, and improving strength for occasional equipment loads.

Based on our field exploration and test results, we anticipate precipitation and surface waters will likely infiltrate the soils beneath the field. We recommend construction of an under-drain trench system for storage of excess precipitation and/or to direct the water to an infiltration basin or positive drainage system. It is important that any system to which it is connected be separated so that backflow during heavy rainfalls will not saturate the soils beneath the synthetic turf. We recommend that the client and the designer consider “Guidelines for Synthetic Base Systems” by the Synthetic Turf Council in designing the proposed synthetic turf.

MEG Page 9 of 14

The synthetic turf components should be installed over a constructed section as per turf manufacturers and designers’ recommendations. Generally permeable aggregate layers with a supporting structural fill are placed as the foundation structure for the synthetic turf.

7.4 Site Preparation

We recommend all sod and other organics be removed from the footprint of the new fields.

Based on our borings and to mitigate soil movement as recommended in the Subgrade Modifications Table 7.1. to improve the subgrade modifications drainage at the base of the excavations should be firm, uniform, soil surfaces shaped and graded so water does not collect and pond in the field footprints.

7.5 Trench Drain

We understand the drainage system for the field will likely include trench drains that may or may not contain piping. The drain system should be designed to eliminate which isolated areas of vertical displacement. Drain system pipes, if used may consist of a material such as high-density polyethylene (HDPE).

Infiltration trenches may be constructed directly beneath the structural section and should be as deep and wide as necessary with considerations for frost depth, water storage capacity, infiltration characteristics of surrounding soils, and other requirements such as separation depth from ground water, which average approximately six (6) feet bgs in our borings at the time of drilling. We recommend climatic data for the site be reviewed and storm rainfall amounts be examined to establish maximum storm frequency, duration and intensity for the site.

If piping is used in the infiltration system, the trench should be a minimum of 2 feet wider than the pipe diameter. Perforated pipe should be placed in the trenches if the trenches if the water is to be conveyed to a storm water collection system. The minimum size of the pipes will be controlled by hydraulic demands on the drainage system and required storage. If additional storage is desired, the diameter of perforated pipe or trench depth may be increased. Pipes should be placed no deeper than 6 inches from the bottom of the trench and no shallower that 1 foot below of the structural section for the field.

After the site is prepared, the infiltration trench should be constructed and piping (if used) be installed along the perimeter of the field. We recommend the stability of excavated slopes be made the responsibility of the contractor, as they will be most familiar with conditions encountered in the excavations and have direct control of working conditions in the field. The work should be accomplished in general accordance with applicable local, state and federal standards. It is also important to note temporary excavation slopes may initially stand steep but slough and cave as they dry out, particularly when equipment is operated nearby. If perforated pipe is installed in the trench, it should be bedded with a relatively porous fill material such as pea gravel/drain rock or structural fill.

The trench should be lined on all sides (including the top) with Class 2 [as defined by American Association of Highway and Transportation Officials (AASHTO) M 288]

MEG Page 10 of 14 nonwoven separator fabric with an elongation equal to or greater than 50 percent or as per manufacturers or designers’ recommendations.

7.6 Drainage

Surface runoff may infiltrate open excavation during construction. The contractor should be responsible for maintaining site grade to prevent surface water from entering excavation during periods of high rains. We recommend the site be controlled to provide positive surface drainage away from structures and field surfaces and off the site. Water should drain to the perimeter of the field water that reaches the outer edges of the field can drain into infiltration trenches around the field perimeter or be collected in pipes and conveyed to an infiltration basin.

8.0 CONSIDERATIONS DURING CONSTRUCTION

8.1 Site Grading Recommendations

Site grading plans can result in changes in almost all aspects of foundation recommendations. We have prepared the foundation recommendations based on the existing ground surface; there is no surcharge addition for the stratigraphic conditions encountered at the time of our study. If site grading plans differ from existing grades by more than plus or minus 1 foot, we must be retained to review the site grading plans prior to bidding the project for construction. This will enable us to provide input for any changes in our original recommendations that may be required as a result of site grading operations or other considerations.

8.2 Site Drainage Recommendations

Drainage is one of the most important aspects to be addressed to ensure the successful performance of any foundation. Positive surface drainage should be implemented prior to, during and maintained after construction to prevent water ponding at or adjacent to the building facilities. It is recommended that the building and site design include rain gutters, downspouts and concrete gutters to channel runoff to paving or storm drains.

8.3 Site Preparation Recommendations

Building areas and all area to support select fill should be stripped of all vegetation and organic topsoil up to a minimum of 5 ft. beyond the building perimeters. After stripping, remove at least six (6) inches of on-site soil as measured from existing grade when excavation of existing subgrade is not recommended in other sections of this report. The excavated material, if free of organic and/or deleterious material, may be stockpiled for use in the non-structural areas of the site. Where excavation of the subgrade is recommended in this report, the bottom of the excavation will extend at least five (5) feet beyond the limits of the planned building perimeter including canopies and sidewalks.

Exposed subgrades should be thoroughly proof rolled in order to locate and compact any weak, compressible and soft spots. Proof rolling shall be in accordance with TxDOT 2014 Specification Item 216. Proof rolling operations should be observed by the Geotechnical Engineer or his representative to document subgrade condition and preparation. Weak

MEG Page 11 of 14 or soft areas identified during proof rolling or areas where large tree roots have been removed within the limits of excavation should be removed and replaced with a suitable, compacted select fill in accordance with the recommendations presented under the Select Fill Recommendations section of this report. Proof rolling operations and any excavation/backfill activities should be observed by MEG representatives to document subgrade preparation.

Prior to fill placement, the exposed subgrade shall be prepared based on what option is selected from the foundation and pavement recommendations. The exposed subgrade should be prepared, moisture-conditioned by scarifying to a minimum depth as recommended in the foundation and pavement recommendations and recompacting to a minimum 98 percent of the maximum dry density as determined in accordance with ASTM D 698, moisture-density relationship. The moisture content of the subgrade should be maintained within the range of minus two (-2) percentage points below optimum to plus two (+2) percentage points above the optimum moisture content until the fill is permanently covered. The soil should be properly compacted in accordance with these recommendations and tested by MEG personnel for compaction as specified.

8.4 Aggregate Base Course Recommendations

Materials used for aggregate base course shall meet the following requirements:

1. Material shall conform to TxDOT 1993 Specification Item 247, Flexible Base; Type A, Grades 1 through 5. Permeable aggregate base material not meeting the gradation requirements may be allowed when approved by the project engineer and concurrence by MEG.

2. Material conforming to TxDOT 1993 Specification Item 247, Flexible Base, Type D, Grade 6 and defined as Caliche (argillaceous limestone, calcareous or calcareous clay particles) is not considered suitable for use as select fill materials at this site.

3. Soils classified, as CH, MH, OH, OL, PT, SM, SC, GM, GC, CL, ML under the USCS are not considered suitable for use as select fill materials at this site.

Aggregate base course shall be placed in loose lifts not to exceed 8 inches (6 inches compacted) and compacted to a minimum 98 percent of the maximum dry density as determined in accordance with ASTM D 698. The moisture content of the aggregate base course shall be maintained within the range of minus two (-2) percentage points below optimum to plus three (+3) percentage points above the optimum moisture content until the aggregate base course is permanently covered. The aggregate base course should be properly compacted in accordance with these recommendations and tested by MEG personnel for compaction as specified. As previously stated, we understand the below-grade field turf is planned to be supported by gravel bedding/aggregate base underlain by native soils, and as such, compaction may be achieved via means of hand tamping.

8.5 Site Fill Recommendations

Site fill shall be placed in loose lifts not to exceed 8 inches (6 inches compacted) and compacted to a minimum 98 percent of the maximum dry density as determined in

MEG Page 12 of 14 accordance with ASTM D 698. The moisture content of the fill shall be maintained within the range of zero (0) percentage points below optimum to plus two (+2) percentage points above the optimum moisture content until the fill is permanently covered. The site fill should be properly compacted in accordance with these recommendations and tested by MEG personnel for compaction as specified.

8.6 Back Fill Recommendations

Back fill shall be placed in loose lifts not to exceed 8 inches (6 inches compacted) and compacted to a minimum 95 percent of the maximum dry density as determined in accordance with ASTM D 698. The moisture content of the fill shall be maintained within the range of zero (0) percentage points below optimum to plus two (+2) percentage points above the optimum moisture content until the fill is permanently covered. The back fill should be properly compacted in accordance with these recommendations and tested by MEG personnel for compaction as specified.

8.7 Utility Considerations

Utilities that project through the slab-on-grade, slab-on-fill, floating floor slabs, or any other rigid unit should be designed with some degree of flexibility or with sleeves. Such features will help reduce the risk of damage to utility facilities from soil movements related to shrinkage and expansion.

8.8 Utility Trench Recommendations

Bedding and initial backfill are buried around utility lines to support and protect the utility.

The secondary backfill above the initial backfill also helps protect and support the foundation and/or pavement above. To ensure that settlement is not excessive in this secondary backfill we recommend the following:

1) If possible, trench and install utilities prior to work such as lime treatment and/or compaction of subgrade or placement of other fills or bases.

2) Place, moisture condition and compact the secondary backfill in accordance with the pertinent project requirements. Within the footprint of a building pad the secondary backfill should meet the same compaction requirements for select fill.

Within the footprint of a pavement structure the secondary backfill should meet the same compaction requirements for the subgrade. When compaction of the subgrade is not specified it should meet the same compaction level of the adjacent natural ground. An alternative to compaction of secondary backfill is the use of flowable fill where secondary backfill is to be placed. If properly designed, the flowable fill can be excavated easily at a later date if necessary. No compaction and no testing is required when properly designed flowable fill is used.

8.9 Excavation, Sloping and Benching Considerations

The soils encountered in the borings can easily be excavated using conventional earthwork equipment. No major hard soil and/or rock units were encountered in the borings through completion depth. In the case that excavations occur through granular

MEG Page 13 of 14 soil or submerged soils it will be necessary to either slope the excavation sidewalls or provide temporary bracing to control excavation wall instability.

The side slopes of excavations through the overburden soils should be made in such a manner to provide for their stability during construction. Pipe lines or other facilities which are constructed prior to or during the currently proposed construction and which require excavation should be protected from loss of end bearing or lateral support.

Temporary construction slopes and/or permanent embankment slopes should be protected from surface runoff water. Site grading should be designed to allow drainage at planned areas where erosion protection is provided instead of allowing surface water to flow down unprotected slopes.

Permanent slopes at the site should be as flat as practical to reduce creep and occurrence of shallow slides. The following slope angles are recommended as maximums. The presented angles refer to the total height of a slope. Site improvement should be maintained away from the top of the slope to reduce the possibility of damage due to creep or shallow slides.

Table 8.1. Slopes Angles Requirements

Height (ft.) Horizontal to vertical 0 – 3 1:1 3 – 6 2:1 6 – 9 3:1 >9 4:1

The contractor or persons doing the trenching should adhere to the current Occupational Health and Safety Administration (OSHA) guidelines on trench excavation safety and protection measures. Other industry standards may be applicable. The collection of specific geotechnical data and development of a plan for trench safety, sloping, benching or various types of temporary shoring, is beyond the scope of the this study.

8.10 Lime Treated Subgrade

Lime stabilization of the soils may be used for soil shrink and swell mitigation and to increase the structural capacity of the subgrade as platform for the pavement. It is recommended that the subgrade plasticity index be verified after the site is stripped of the loose topsoil and the subgrade is exposed up to the subgrade elevation. Stabilization treatment of the subgrade soils may also be utilized to provide a platform for the base for resistance to moisture intrusion and changes. Prevention of moisture intrusion is extremely important to the life of a pavement. Increases in moisture content of the subgrade and the base will significantly reduce the material’s structural ability to carry loads. The optimum lime content should reduce the PI of the soil to 20 or less and should result in a soil lime mixture with a pH of at least 12.4 when tested in accordance with ASTM C 977, Appendix XI. The lime should be blended with a mixing device such as a pulvermixer to produce a soil mixture passing water added and be allowed to cure for at least 48 hours. After curing the lime soil mixture it shall pass the grading requirements of

MEG Page 14 of 14

TxDOT 2014 Specification Item 260 and compacted to a minimum 98 percent of the maximum dry density determined in accordance with ASTM D 698 at moisture contents ranging from minus two (-2) percentage points below optimum to plus two (+2) percentage points above optimum moisture content. If the in place gradation requirements can be achieved during the initial mixing, the remixing after the curing period can be eliminated.

Please note that there is a relationship between the time of mixing of the lime and soils with the maximum dry density. Any mixture older than three (3) days will require determination of new moisture density relationships.

9.0 PROJECT REVIEW AND QUALITY CONTROL

Each project site is unique and it is important that the appropriate design data, construction drawings, specifications, change orders and related documents be reviewed by the respective design and construction professionals participating in this project. The performance of foundations, construction building pads and/or parking areas for this project will depend on correct interpretation of our geotechnical engineering report and proper compliance of and adherence to our geotechnical recommendations and to the construction drawings and specifications.

It is important that MEG be provided the opportunity to review the final design and construction documents to check that our geotechnical recommendations are properly interpreted and incorporated in the design and construction documents. We cannot be responsible for misinterpretations of our geotechnical recommendations if we have not had the opportunity to review these documents. This review is an additional service and not part of our project scope.

MEG should be retained to provide construction materials testing and observation services during all phases of the construction process of this project. As the Geotechnical Engineer of Record, it is important to let our technical personnel provide these services to make certain that our recommendations are interpreted properly and to ensure that actual field conditions are those described in our geotechnical report. Since our personnel are familiar with this project, MEG’s participation during the construction phase of this project would help mitigate any problems resulting from variations or anomalies in subsurface conditions, which are among the most prevalent on construction projects and often lead to delays, changes, costs overruns, and disputes. If the client does not follow all of our recommendations presented in this report and/or addendums to this report, the client assumes the responsibility and liability of such actions and will hold our firm harmless and without responsibility and liability for client’s actions.

A construction testing frequency plan and budget needs to be developed for the required construction materials engineering and testing services for this project. Before construction, we recommend that MEG, the project design team members and the project general contractor meet and jointly develop the testing plan and budget, as well as review the testing specifications as it pertains to this project. A failure to implement a complete testing plan will negate the recommendations provided in this report.

MEG looks forward to the opportunity to provide continued support on this project.

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APPENDIX A

CUSTOM SOIL RESOURCE REPORT

APPENDIX B

PROJECT LOCATION, TOPOGRAPHIC AND BOREHOLE

LOCATION MAPS

PROPOSED

CITY OF EDINBURG MUNICIPAL PARK

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

M

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NOT TO SCALE

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APPROXIMATE

PROJECT LOCATION

MILLENNIUM ENGINEERS GROUP, INC.

5804 N. GUMWOOD AVENUE

PHARR, TEXAS 78577

WWW.MEGENGINEERS.COM

TEL: 956-702-8500

FAX: 956-702-8140

PROJECT SITE LOCATION MAP

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

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NOT TO SCALE

N

APPROXIMATE

PROJECT LOCATION

MILLENNIUM ENGINEERS GROUP, INC.

5804 N. GUMWOOD AVENUE

PHARR, TEXAS 78577

WWW.MEGENGINEERS.COM

TEL: 956-702-8500

FAX: 956-702-8140

PROJECT TOPOGRAPHY MAP

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

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BOREHOLE DEPTH

N

= 15'

MILLENNIUM ENGINEERS GROUP, INC.

5804 N. GUMWOOD AVENUE

PHARR, TEXAS 78577

WWW.MEGENGINEERS.COM

TEL: 956-702-8500

FAX: 956-702-8140

PROJECT BOREHOLE LOCATION MAP

P-1

P-2 P-3

BASEBALL FIELDS TURF

EDINBURG, HIDALGO COUNTY, TEXAS

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NOT TO SCALE

BOREHOLE DEPTH

N

= 15'

MILLENNIUM ENGINEERS GROUP, INC.

5804 N. GUMWOOD AVENUE

PHARR, TEXAS 78577

WWW.MEGENGINEERS.COM

TEL: 956-702-8500

FAX: 956-702-8140

PROJECT BOREHOLE LOCATION MAP

P-4

P-6 P-5

APPENDIX C

PROJECT BORING LOGS AND PROFILE

Project: Proposed City of Edinburg Municipal Park Baseball Fields Turf

Project Location: Edinburg, Hidalgo County, Texas

Project Number: 01-23-29170

Log of Boring B-1

Date(s) Drilled 12/21/2023

Drilling Method Straight Flight

Drill Rig Type Simco 2800

Groundwater Level and Date Measured Not Encountered

Borehole Backfill Subgrade Cuttings

Logged By A. Guerrero

Drill Bit Size/Type 4" soil bit

Drilling Contractor MEG Drilling

Sampling Method(s) SPT

Location See Boring Location Map

Checked By Raul Palma

Total Depth of Borehole 15 feet bgs

Approximate Surface Elevation Hammer Data 140 lb., 30 in. drop, auto trip

M at er ia l T yp e

CL

CH

LL

PI

U C

, k sf

Pe rc en t F in es

G ra ph ic

L og

W at er C on te nt

MATERIAL DESCRIPTION

lean CLAY w/ sand to sandy lean CLAY, brown, dry to moist, soft to stiff fat CLAY to fat CLAY w/ sand, brown, dry to moist, med. stiff to very stiff

Bore Termination

D ep th (f ee t)

Sa m pl e

N um be r

Sa m pl e

Ty pe

Sa m pl in g R es is ta nc e, bl ow s/ ft

El ev at io n (fe et

Sheet 1 of 1

Project Location: Edinburg, Hidalgo County, Texas

Project Number: 01-23-29170

Log of Boring B-2

Date(s) Drilled 12/21/2023

Drilling Method Straight Flight

Drill Rig Type Simco 2800

Groundwater Level and Date Measured Not Encountered

Borehole Backfill Subgrade Cuttings

Logged By A. Guerrero

Drill Bit Size/Type 4" soil bit

Drilling Contractor MEG Drilling

Sampling Method(s) SPT

Location See Boring Location Map

Checked By Raul Palma

Total Depth of Borehole 15 feet bgs

Approximate Surface Elevation Hammer Data 140 lb., 30 in. drop, auto trip

M at er ia l T yp e

CL

CH

LL

PI

U C

, k sf

Pe rc en t F in es

G ra ph ic

L og

W at er C on te nt

MATERIAL DESCRIPTION

lean CLAY w/ sand to sandy lean CLAY, brown, dry to moist, soft to stiff fat CLAY to fat CLAY w/ sand, brown, dry to moist, med. stiff to very stiff

Bore Termination

D ep th (f ee t)

Sa m pl e

N um be r

Sa m pl e

Ty pe

Sa m pl in g R es is ta s/ ft

El ev at io n (fe et

Project Location: Edinburg, Hidalgo County, Texas

Project Number: 01-23-29170

Log of Boring B-3

Date(s) Drilled 12/21/2023

Drilling Method Straight Flight

Drill Rig Type Simco 2800

Groundwater Level and Date Measured Not Encountered

Borehole Backfill Subgrade Cuttings

Logged By A. Guerrero

Drill Bit Size/Type 4" soil bit

Drilling Contractor MEG Drilling

Sampling Method(s) SPT

Location See Boring Location Map

Checked By Raul Palma

Total Depth of Borehole 15 feet bgs

Approximate Surface Elevation Hammer Data 140 lb., 30 in. drop, auto trip

M at er ia l T yp e

CL

CH

LL

PI

U C

, k sf

Pe rc en t F in es

G ra ph ic

L og

W at er C on te nt

MATERIAL DESCRIPTION

lean CLAY w/ sand to sandy lean CLAY, brown, dry to moist, soft to stiff fat CLAY to fat CLAY w/ sand, brown, dry to moist, med. stiff to very stiff

Bore Termination

D ep th (f ee t)

Sa m pl e

N um be r

Sa m pl e

Ty pe

Sa m pl in g R es is ta s/ ft

El ev at io n (fe et

Project Location: Edinburg, Hidalgo County, Texas

Project Number: 01-23-29170

Log of Boring B-4

Date(s) Drilled 12/21/2023

Drilling Method Straight Flight

Drill Rig Type Simco 2800

Groundwater Level and Date Measured Not Encountered

Borehole Backfill Subgrade Cuttings

Logged By A. Guerrero

Drill Bit Size/Type 4" soil bit

Drilling Contractor MEG…