Attachment 7 TI Design Standards.pdf

Tactical Infrastructure Design Standards August 2020 (Version V.5)

Tactical Infrastructure Design Standards

TACTICAL INFRASTRUCTURE DESIGN STANDARDS

Version 5, August 2020

DEPARTMENT OF HOMELAND SECURITY

CUSTOMS AND BORDER PROTECTION

UNITED STATES BORDER PATROL

PROGRAM MANAGEMENT OFFICE DIRECTORATE

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TABLE OF CONTENTS

CHAPTER 1: ROAD, BRIDGE & SIGNAGE DESIGN STANDARDS ..................................................... 1-1 SECTION 1.1 ROAD TYPES .......................................................................................................................................... 1-1

1.1.1 Purposes of Roads ................................................................................................................................... 1-3 SECTION 1.2 ROAD PAVEMENT DESIGN STANDARDS ......................................................................................... 1-5

1.2.1 Preliminary Soil Investigation ............................................................................................................... 1-5

1.2.2 Concrete Pavement Section (FC-1 and LWC) ...................................................................................... 1-6

1.2.3 Asphalt Pavement Section (FC-1) .......................................................................................................... 1-7

1.2.4 Pavement Section with Soil Stabilization Additives (FC-1, FC-2 and FC-3) ...................................... 1-8

1.2.5 Aggregate Surface Course Pavement Section (FC-2, FC-5) .............................................................. 1-10

1.2.6 Chip Seal Pavement Section (FC-1, FC-2) ............................................................................................ 1-11

1.2.7 Pavement Section with Polymer Blend Resin (i.e., Dust Control) (FC-2, FC-5) .............................. 1-12

1.2.8 Pavement Section with Cellular Confinement or Mechanical Concrete (FC-2, FC-3 and FC-5) ... 1-12

1.2.9 Articulated Concrete Mat Pavement Section (LWC) .........................................................................1-14

SECTION 1.3 ROAD CROSS SECTION DESIGN STANDARDS ................................................................................ 1-15

1.3.1 Cross Slope ............................................................................................................................................ 1-16

1.3.2 Safety Shoulder ...................................................................................................................................... 1-17

1.3.3 Foreslope & Backslope........................................................................................................................... 1-17

1.3.4 Guardrail .................................................................................................................................................1-18

SECTION 1.4 ROAD GEOMETRIC DESIGN STANDARDS ......................................................................................1-19

1.4.1 Sight Distances ...................................................................................................................................... 1-19

1.4.2 Horizontal Alignment .......................................................................................................................... 1-19

1.4.3 Vertical Alignment ................................................................................................................................ 1-21

1.4.4 Design Speed ......................................................................................................................................... 1-25

1.4.5 Intersections .......................................................................................................................................... 1-25

1.4.6 Turnarounds & Pullouts ....................................................................................................................... 1-26

SECTION 1.5 BRIDGE DESIGN STANDARDS ....................................................................................................... 1-28 SECTION 1.6 SIGNAGE DESIGN STANDARDS ..................................................................................................... 1-30 SECTION 1.7 DRAINAGE PROTECTION DESIGN STANDARDS ............................................................................. 1-31

1.7.1 USIBWC Floodplain .............................................................................................................................. 1-31

1.7.2 General Drainage .................................................................................................................................. 1-32

1.7.3 Low Water Crossings ............................................................................................................................ 1-33

1.7.4 Culverts .................................................................................................................................................. 1-34

1.7.5 Roadside Drainage ................................................................................................................................ 1-35

1.7.6 Erosion Control ..................................................................................................................................... 1-35

CHAPTER 2: WALL DESIGN STANDARDS ...................................................................................... 2-37 SECTION 2.1 WALL TYPES ...............................................................................................................................2-37 SECTION 2.2 WALL DESIGN STANDARDS ........................................................................................................ 2-39

2.2.1 Wall Types ............................................................................................................................................ 2-39

2.2.2 Wall Design Criteria ............................................................................................................................ 2-40

SECTION 2.3 VEHICLE FENCE DESIGN STANDARDS ......................................................................................... 2-43

2.3.1 Vehicle Fence Types ............................................................................................................................ 2-43

2.3.2 Vehicle Fence Design Criteria ............................................................................................................ 2-43

SECTION 2.4 WALL DRAINAGE PROTECTION & EROSION DESIGN STANDARDS .............................................. 2-45

2.4.1 Drainage Conveyance, Scour & Erosion Control Design ................................................................. 2-45

CHAPTER 3: GATE DESIGN STANDARDS ....................................................................................... 3-47 SECTION 3.1 GATES TYPES .............................................................................................................................. 3-47 SECTION 3.2 MANUALLY OPERATED GATE DESIGN STANDARDS .................................................................... 3-48

3.2.1 Manually Operated Gate Types .......................................................................................................... 3-48

3.2.2 Manually Operated Gate Design Criteria .......................................................................................... 3-49

SECTION 3.3 AUTOMATED/MOTORIZED GATE DESIGN STANDARDS ............................................................... 3-51

3.3.1 Automated/Motorized Gate Types ..................................................................................................... 3-51

3.3.2 Automated/Motorized Gate (SLIDE & SWING) Design Criteria .................................................... 3-52 ii

SECTION 3.4 DRAINAGE SWING GATE DESIGN STANDARDS ............................................................................. 3-55

3.4.1 Drainage Swing Gate Design Criteria .................................................................................................3-55

SECTION 3.5 DRAINAGE LIFT GATE DESIGN STANDARDS ................................................................................ 3-56

3.5.1 Drainage lift Gate Design Criteria ...................................................................................................... 3-56

CHAPTER 4: ELECTRICAL DESIGN STANDARDS .......................................................................... 4-58 SECTION 4.1 LIGHTING ................................................................................................................................... 4-58

4.1.1 Code Compliance ................................................................................................................................. 4-58

4.1.2 Lighting Performance Optimization ................................................................................................. 4-59

4.1.3 Luminaires ............................................................................................................................................ 4-60

4.1.4 Lighting Levels ..................................................................................................................................... 4-60

4.1.5 Pole Mounted Lights ............................................................................................................................ 4-61

4.1.6 Gate Mounted Lights ............................................................................................................................ 4-61

4.1.7 Light Pole Design Criteria .................................................................................................................... 4-61

4.1.8 Lighting Controls ................................................................................................................................. 4-62

4.1.9 Lighting Power Distribution ............................................................................................................... 4-62

SECTION 4.2 FIBER OPTIC DESIGN STANDARDS .............................................................................................. 4-63

4.2.1 General Fiber Requirements ............................................................................................................... 4-63

SECTION 4.3 VIDEO SECURITY ........................................................................................................................ 4-64

4.3.1 Camera Requirements ......................................................................................................................... 4-64

SECTION 4.4 RVSS ......................................................................................................................................... 4-65

4.4.1 RVSS Towers ........................................................................................................................................ 4-65

SECTION 4.5 POWER DISTRIBUTION DESIGN STANDARDS .............................................................................. 4-66

4.5.1 Service Entrance .................................................................................................................................. 4-66

4.5.2 Conductors and Conduit..................................................................................................................... 4-66

4.5.3 Junction Boxes...................................................................................................................................... 4-66

4.5.4 Grounding ............................................................................................................................................ 4-66

SECTION 4.6 LIGHTING DRAINAGE PROTECTION DESIGN STANDARDS ........................................................... 4-68

4.6.1 Erosion Control .................................................................................................................................... 4-68

CHAPTER 5: ENFORCEMENT ZONE DESIGN STANDARDS .......................................................... 5-69 SECTION 5.1 ENFORCEMENT ZONE TYPES ...................................................................................................... 5-69 SECTION 5.2 ENFORCEMENT ZONE DESIGN CRITERIA ..................................................................................... 5-70

CHAPTER 6: REFERENCES .............................................................................................................. 6-71 iii

APPENDICES

APPENDIX A …………………………………………………………………….…………….……………. STANDARD SPECIFICATIONS

APPENDIX B ……………………………………………………………….………. WALL, FENCE & GATE STANDARD DETAILS

APPENDIX C ……………………………………………………………………….………...…….. ELECTRICAL STANDARD DETAILS

APPENDIX D ………………………………………………………………..…………….. MISCELLANEOUS STANDARD DETAILS

APPENDIX E …………………………………………………………………..…… ENFORCEMENT ZONE STANDARD DETAILS

APPENDIX F ………………………………………………………………………………….………….. SIGNAGE STANDARD DETAILS

APPENDIX G ………………………………………………………………IBWC RIVER BOUNDARY DESIGN REQUIREMENTS

APPENDIX H ………………………………………………………………IBWC LAND BOUNDARY DESIGN REQUIREMENTS

APPENDIX I …………………………………………………………………..……………..RVSS TOWER DESIGN REQUIREMENTS

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BACKGROUND TO TACTICAL INFRASTRUCTURE STANDARDS

The Department of Homeland Security (DHS) is charged with managing, securing, and controlling the Nation’s borders with a priority mission focus of preventing terrorists and terrorist weapons from entering the United States. U.S. Customs and Border Protection (CBP) represents the front line in defending the United States against terrorists and instruments of terror and protects the economic security of the United States by regulating and facilitating the lawful movement of goods and people across the United States’ borders. U.S. Border Patrol (USBP) is responsible for securing the Nation’s borders against illegal entry of people and goods between ports of entry (POE). This is accomplished through the combined use of border patrol agents, tactical infrastructure, technology and other resources. Tactical Infrastructure generally includes walls or fence to deter persons and/or vehicles from illegally entering the U.S.; border and access roads to help border patrol agents safely interdict and apprehend persons who illegally enter the U.S.; and border lighting to help deter illegal activities. The design standards contained herein were developed for use in the design and repair of Tactical Infrastructure (TI) used by USBP in fulfilling their operational requirements.

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DISCLAIMER

The standards compiled in this document are meant to be minimum design criteria. Each project shall be evaluated for site-specific conditions that may require additional design. For projects that cannot meet the criteria specified in this document due to site specific constraints, a design exception shall be submitted for review. References cited are current at the time this document was compiled. References shall be checked to ensure no updates have been made since the publication of this document.

Chapter 1 – Road, Bridge & Signage Design Standards 1-1

CHAPTER 1: ROAD, BRIDGE & SIGNAGE DESIGN STANDARDS

Section 1.1 ROAD TYPES

Four types of roads have been identified by CBP as part of a system in which roads are maintained to meet specific standards according to their functional classification (FC). The four types are as follows:

• FC-1 Paved Road (Figure 1) – All-weather road constructed using flexible or rigid pavement (e.g., asphalt, concrete). The road has one lane with a total road width of 12-16 feet or two lanes with a total road width of 16-20 feet.

Figure 1 – FC-1 Paved Road

• FC-2 All-Weather Road (Figure 2) – All-weather road consisting of a surface of imported aggregate material, such as milled bituminous material or processed aggregate gravel mixture. The road has one lane with a total road width of 12-16 feet or two lanes with a total road width of 16-20 feet.

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Figure 2 – FC-2 All-Weather Road

• FC-3 Graded Earth Road (Figure 3) – An unpaved road constructed of graded, native material. The road has one lane with a total road width of 12-16 feet or two lanes with a total road width of 16-20 feet.

Figure 3 – FC-3 Graded Earth Road

• FC-5 Sand Road (Figure 4) – Sand dunes road that follows the natural contours with improvements to road sub-base, by means of cellular confinement or mechanical concrete, and road pavement section only. The road one lane with a total road width of 12-16 feet has two lanes with an overall road width of 16-20 feet.

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Figure 4 – FC-5 Sand Road

1.1.1 PURPOSES OF ROADS

There are four road categories identified in the CBP program: patrol road, access road, maintenance road, and operations road. For the purposes of these design standards, the four FC road types are the baseline for all patrol, maintenance and access road improvements or new construction, including any maintenance and repair activities for these road categories. Operations roads used by USBP, but not constructed by CBP as part of tactical infrastructure, are not covered under these TI Design Standards.

See Section 1.3, Road Cross Section Design Standards, for additional cross section features.

1.1.1.1 PATROL ROAD

Patrol roads are generally oriented parallel with the border and are used for direct enforcement of the border. Patrol roads are typically 20 feet wide with 2-foot shoulders (see Figure 13, Patrol Road Typical Section (20 Feet Wide Road)) and are posted for 25 miles per hour travel. These roads shall be designed to allow safe passage of two vehicles at the same time. New or improved patrol roads shall be designed for a 25-year life and be constructed as FC-1, FC-2, or FC-5 roads, depending on operational and funding requirements and on a project-by-project basis.

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1.1.1.2 ACCESS ROAD

Access roads generally provide access from public roads to the patrol roads and to TI not accessible from a patrol road. Access roads are typically one-lane roads with pullouts and turnarounds to accommodate two-way traffic. The width of the access roads shall be 12 feet for one-lane roads (see Figure 14, Access Road Typical Section (12 Feet Wide Road)) but shall widen to 16 feet at curves and points of short sight distance. Access road width and pullout placement shall be designed to allow safe passage of two vehicles at the same time. The maximum width of access roads shall be 16 feet. Access roads shall be designed for a 25-year life and may be constructed as any of the four FC road types depending on operational and funding requirements and on a project-by-project basis.

1.1.1.3 MAINTENANCE ROAD

Maintenance roads are required for maintaining TI following the completion of construction. In general, maintenance roads shall follow access road requirements, unless otherwise noted. For locations where the patrol road follows the alignment of the international land border and the edge of the patrol road closest to Mexico is less than 20 feet from the border wall, the patrol road may double as the maintenance road. For locations where a patrol road has deviated away from the international land border due to terrain or other obstacles and obstructions, a minimum 12 feet wide maintenance road immediately adjacent to the border wall shall be required. Each end of the maintenance road shall be required to tie back into the patrol road. For locations where border wall alignments are constructed along international river border and the patrol road is on the river side of the border wall, a maintenance road is required on the US side of the border wall. Maintenance roads along border walls on the international river border shall be 20 feet wide with the edge of the road closest to river offset 6 feet from the border wall.

1.1.1.4 OPERATIONS ROAD

Operations roads are typically dirt or aggregate roads located on private lands that provide valuable operational mobility for Border Patrol field agents. While operational roads are very similar in function to access roads, they are not covered under these TI Design Standards due to CBP not possessing real estate interest (fee or easement) in the road. However, CBP may enter into a license agreement with the landowner to allow CBP to conduct minor maintenance on the road due to heavier traffic volume.

Chapter 1 – Road, Bridge & Signage Design Standards 1-5

Section 1.2 ROAD PAVEMENT DESIGN STANDARDS

Pavement section design is dependent on site-specific factors, such as soil conditions and vehicular traffic, and on the selected FC road type identified in Section 1.1, Road Types. Standard pavement section solutions used for CBP patrol, maintenance and access roads are discussed in depth in Section 1.2.2, Concrete Pavement Section, through Section 1.2.9, Articulated Concrete Mat Pavement Section. The applicability of each pavement type to the various road types is denoted in the heading of each pavement type. Patrol and access road pavement design criteria shall conform to the U.S. Department of Defense (DOD) Unified Facilities Criteria (UFC) 3-250-01 (2016a) for flexible and rigid pavements, and UFC 3-250-09FA (2004b) for aggregate surface roads. Pavement design of roadways trafficked by standard American Association of State Highway and Transportation Officials (AASHTO) vehicles, shall conform to the design criteria of the Department of Transportation (DOT) in the state in which the project is located. For pavement design of roadways trafficked by special military vehicles, pavement thickness and compaction requirements shall be determined using PCASE (Pavement-Transportation Computer Aided Structural Engineering) (U.S.

Department of Defense [DOD] Tri-Services, n.d.), a computer program developed by the U.S. Army Corps of Engineers (USACE). Refer to UFC 3-201-01 (2018) for minimum design criteria, minimum pavement thicknesses and clarification on design vehicles and design traffic. Use of the codes and criteria referenced above and throughout the road pavement design standards, when developing the pavement design sections, shall be based on geotechnical recommendations specific to each road improvement project.

Regardless of the pavement section selected for any road type, the road shall be graded in both profile and cross slope to mitigate erosion from drainage run-off. All drainage crossings shall be protected by appropriate measures such as, but not limited to, articulated concrete block, concrete pavement, culverts, roadside ditches, or a combination thereof. See Section 1.7, Drainage Protection Design Standards for erosion protection and conveyance methods.

Road pavement final design and preparation of construction documents shall be the responsibility of the Designer of Record (DOR) based on the minimum criteria and code requirements established herein and project specific geotechnical recommendations.

1.2.1 PRELIMINARY SOIL INVESTIGATION

The soil subgrade shall be evaluated to determine the roadway cross sectional thicknesses. Prior to field investigations, conduct a general survey of the topographic and subsurface conditions and evaluate the previous performance of existing pavements within the most recent 5 years. Additional sources of information for preliminary site analysis include earlier subsurface investigations at or near the site, U.S.

Geological Survey (USGS) (n.d.) maps, and soil survey maps. A geotechnical engineer in accordance with USACE Engineering Manual (EM) 1110-1-1084 should define the scope of subsurface investigation (1982). In some cases, geophysical tests may be required in addition to geotechnical tests. Subsurface investigations, including test pits and boring holes, shall utilize a maximum spacing of 400 feet. Spacing may be increased to 1,500 feet if previous investigations indicate soil uniformity and exploration results continue to indicate soil uniformity. The depth of subsurface exploration shall be a minimum of 6 feet below finished grade.

Where patrol, maintenance and access road improvements require stabilized subgrade prior to placement of the pavement section, per on-site geotechnical recommendations, the depth of stabilized subgrade shall be based on the requirements outlined in UFC 3-250-01 (2016a) for flexible and rigid

Chapter 1 – Road, Bridge & Signage Design Standards 1-6 pavements and in UFC 3-250-09FA (2004b) for aggregate surface pavements. The stabilized subgrade must also meet the strength and durability requirements set forth in UFC 3-250-11 (2004a).

Soil classification shall be according to the Unified Soil Classification System (USCS) in ASTM D2487 (2017b). The California Bearing Ratio (CBR) value shall be determined in accordance with ASTM D6951 (2018c) when using the Dynamic Cone Penetrometer (DCP) test, ASTM D1883 (2016b) when using undisturbed samples, laboratory soaked tests, or field in-place tests.

1.2.2 CONCRETE PAVEMENT SECTION (FC-1 AND LWC)

The concrete pavement section (Figure 5) consists of a cast-in-place concrete slab driving surface.

Typically, this type of surface is used for areas of high traffic or high risk for erosion, such as low water crossings (LWC) and steep profile grades. The concrete slab shall be reinforced by either steel or fiber, and joints shall be placed to control cracking and expansion of the slab. Odd-shaped slabs (those having a length to width ratio greater than 1.25:1) shall be reinforced in both directions within the entire slab area. Slab thickness shall be determined per Appendix F of UFC 3-250-01 (2016a) or the AASHTO Guide for Design of Pavement Structures (1993) using a minimum concrete compressive strength of 3,000 psi, assumed vehicular loading and site-specific soil conditions. The minimum concrete slab thickness shall be 6 inches per UFC 3-201-01 (2018). Traffic volumes on patrol, maintenance and access roads are assumed to 67 vehicles per day or less; 45 passenger and panel or pickup trucks, 16 two-axle trucks, and 6 three or more axle trucks. Thickened edges shall be required for all concrete pavement sections. Where scour at concrete pavement sections is a concern, concrete turndown walls shall be placed in lieu of thickened edges. Concrete pavement can be installed by military or contractor construction. However, prior to specifying concrete pavement section, consideration must be given to the proximity of the site relative to the concrete batch plant, since concrete is required to be placed within 60 to 90 minutes of batching. Where the workability of concrete prior to placing is a concern, concrete retarders or on-site concrete batching may be specified. Prior to specifying on-site concrete batching, an available water source shall be identified and environmental and real estate compliance shall be confirmed. In addition, the accessibility to the site by loaded concrete mixer trucks shall be considered in remote and/or mountainous areas prior to specifying concrete pavement section.

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Figure 5 - Concrete Pavement

To maximize the design life for the concrete pavement section, annual inspections should be planned.

During such inspections, joints and surface cracking should be inspected for signs of wear and cracking.

If any are found, maintenance should include sealing, surface patching and joint repair. Details for LWC can be found in Appendix D, Miscellaneous Standard Details.

1.2.3 ASPHALT PAVEMENT SECTION (FC-1)

Asphalt pavement section (Figure 6) consists of a layer of asphaltic concrete placed over aggregate base and sub-base courses. The total thickness of the asphalt pavement section shall be determined per Appendix E of UFC 3-250-01 (2016a) or the AASHTO Guide for Design of Pavement Structures (1993) using assumed vehicular loading and the CBR as recommended by a civil engineer with geotechnical expertise. The minimum surface course thickness shall be 2 inches with a minimum overall pavement section of 6 inches per UFC 3-201-01 (2018). Traffic volumes on patrol, maintenance and access roads are assumed to 67 vehicles per day or less; 45 passenger and panel or pickup trucks, 16 two-axle trucks, and 6 three or more axle trucks. Placement of asphalt pavement sections, applicable to FC-1 road type, shall be limited with respect to the steepness of the patrol road, maintenance or access road profile grade. See

Chapter 1 – Road, Bridge & Signage Design Standards 1-8

Section 1.4.3.1, Profile Grades, for maximum profile grade to which asphalt should be placed based on industry standards and equipment capabilities.

Asphalt concrete shall be a performance-grade asphalt binder conforming to the requirements of AASHTO Provisional Standard M 320-17 (American Association of State Highway and Transportation Officials [AASHTO], 2018b).

Figure 6 – Asphalt Pavement

Asphalt requires bi-annual inspection for the first 10 years and annual inspection thereafter. Repairs include crack sealing, pothole patching, and other repairing. Milling and resurfacing are typically required every 15 years.

1.2.4 PAVEMENT SECTION WITH SOIL STABILIZATION ADDITIVES (FC-1, FC-

2 AND FC-3)

Soil stabilization can be performed with the use of cement or lime additives in order to provide a stronger and more durable pavement section. Soil stabilization using cement additives is typically used to improve the surface course of a patrol, maintenance or access road to a point to where it is considered an FC-1 or FC-2 road type. Often, soil cement stabilization is selected when steeper road grades are needed (see

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Section 1.4.3.1 Profile Grades) or where there is a greater potential for drainage across the road that would cause erosion to an FC-2 or FC-3 patrol, maintenance or access road. Soil stabilization using lime additives improves native subgrades that have low CBR values. Low subgrade CBR values can lead to poor performance and impact longevity of the road that may not otherwise be considered prone to damage from erosion. Since soil stabilization with lime additives is applied to subgrade, the finished road type can be any of the FC roads identified within the TI Design Standards. Both cement and lime additives work well for rural, urban, and mountainous areas; however, availability of water should be considered prior to selecting the soil stabilization with cement additives as discussed in Section 1.2.4.1, Soil Stabilization with Cement Additive (Soil Cement). Placement of soil stabilization with additives shall be limited with respect to the steepness of the patrol, maintenance or access road profile grade. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which surface course stabilization should be placed based on industry standards and equipment capabilities. In addition, prior to selecting pavement section with soil stabilization additives, a geotechnical engineer or civil engineer with geotechnical expertise shall evaluate native soil conditions to ensure properties are conducive to placement of cement or lime. Once deemed applicable for the site, soil stabilization with additives shall be designed and proportioned in accordance with the recommendations of UFC 3-250-11 (2004a) and site-specific geotechnical recommendations.

1.2.4.1 SOIL STABILIZATION WITH CEMENT ADDITIVE (SOIL CEMENT)

The mixing of cement additive (and water) to soils can be used to improve patrol, maintenance or access roads by both in-situ application and surface application methods. For the in-situ application method, water and cement are added directly to the in-situ soils or on-site surface course material and then mixed with heavy equipment such as large tillers. The surface application method involves pre-mixing of the cement, aggregate, and water in a pug mill or at an off-site plant, subsequent transportation to the site of the application, and application with grading equipment and compactors. Both soil cement methods require compaction with heavy, rubber-tired rollers. Seven days of curing time is recommended before heavy traffic on any road constructed with soil cement.

Soil cement mix design shall have a plasticity index (PI) that is less than 12 and less than 15 percent passing through a No. 200 sieve. Soil types with fat clays (CH) or organics will affect the cement strength thus do not work well with either of the soil cement application methods. Availability and quality of water shall also be considered when determining the applicability of soil cement. Similar to the placement of concrete, water is a key component for both soil cement application methods.

While mixing of soil cement off-site then utilizing the surface application method will reduce the amount of water needed on-site, as compared to mixing on-site with a pug mill or the in-situ application method, the amount and quality of water needed shall be evaluated prior to selecting soil cement.

Maintenance of soil cement treated roads requires bi-annual inspections. When repairs to cracking and potholing are required, they must be completed with full-depth surface replacement using either soil cement or concrete. No skin patches are permitted. The benefit of using cement rather than lime stabilization, discussed in Section 1.2.4.2, Soil Stabilization with Lime Additives (Lime Stabilization), is that cement is typically less susceptible to erosion if designed and applied properly.

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Figure 7 – Soil Stabilization with Additives

1.2.4.2 SOIL STABILIZATION WITH LIME ADDITIVES (LIME STABILIZATION)

The addition of lime to soils can be used to improve patrol, maintenance and access roads by stabilizing native subgrade materials. Since lime stabilization does not provide a rigid pavement similar to soil cement, it should only be used as subsurface treatment. By injecting lime into native soils, the deeper subgrade soil CBR can be increased thus allowing for a reduced thickness in the selected surface course application. In addition, lime treatment can also be mixed with shallower sub-grade soil to increase the CBR and reduce the surface course thickness. Lime works similarly to soil cement but is used in conditions in which native soils are particularly clayey, with PI greater than

12. However, lime treated soils are easier to repair than soil cement applications, especially when used in conjunction with aggregate surface course or grade dirt roads, since there is no need to remove entire pavement sections. If road maintenance is noted to be requiring more general blading to remove ruts and rough patches, lime can be directly injected more deeply into existing ground through the in-place surface course. Lime shall be quicklime only and shall be used to treat clayey soils with a PI between 5 and 30 and minimum fines content of 35 percent passing through a No. 200 sieve. The design life of lime-stabilized roads can be extended by applying a dust palliative to the surface of the roads. This serves to lock the fines in place, reduce raveling of the surface aggregate, as well as water infiltration into the road during wet weather.

1.2.5 AGGREGATE SURFACE COURSE PAVEMENT SECTION (FC-2, FC-5)

Aggregate surface course roads (Figure 8) work well for patrol, maintenance or access roads located in rural, urban, and mountainous areas. No special equipment is required, and construction can be completed using standard equipment such as excavators, compactors, graders, and water trucks. The thickness of the aggregate surface course shall be determined according to UFC 3-250-09FA (2004b) using assumed vehicular loading and the CBR as recommended by a civil engineer with geotechnical expertise. The thickness of aggregate surface course shall be placed over prepared subgrade, which could simply be compacted native material, scarified and compacted native material, or select sub-base material per on site-specific geotechnical recommendations. Aggregate surface course is applicable for

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FC-2 and FC-5 roads. If aggregate surface course is applied to FC-5 roads, cellular or mechanical concrete sub-surface treatments are required. See Section 1.2.8, Pavement Section with Cellular Confinement or Mechanical Concrete, for cellular confinement and mechanical concrete application. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which aggregate surface course pavement sections should be placed due to concerns of erosion and lack of traction. Performance of aggregate surface course roads is dependent on the gradation and quality of the surface course, proper grading of the road to provide adequate drainage, and regular maintenance.

Aggregate surface roads require annual inspections with supplemental inspections after storm events.

Repairs and maintenance include blading to remove ruts or wash-boarding and placing additional material as needed. The level of maintenance depends upon the use of the road and the impact of drainage conditions on the surface.

Figure 8 – Aggregate Surface Course Road

1.2.6 CHIP SEAL PAVEMENT SECTION (FC-1, FC-2)

Chip seal (Figure 9) is a thin layer of aggregate and asphalt placed on compacted aggregate base course.

Two coats of chip seal are required. After each coating, the surface is rolled and compacted. Chip seal provides a sealed surface but does not provide structural strength, so it can be cost effective on roads where dust mitigation or water infiltration into the base or subgrade requires control. In addition, chip seal can be used to repair minor cracks in asphalt pavement. Chip seal pavement section shall be designed and specified according to the California Department of Transportation (Caltrans) “Maintenance Technical Advisory Guide, Volume I” (2008). Placement of chip seal, applicable to FC-1 and FC-2 road types, shall be limited with respect to the steepness of the patrol, maintenance or access road profile grade. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which chip seal should be placed based on industry standards and equipment capabilities.

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Figure 9 - Chip Seal

Inspections are required annually. Repairs include crack sealing with use of hot tar and sand, filling potholes with cold patch, or pulverize and re-apply the chip seal for segments needed. Re-application is estimated to be needed every 6-10 years.

1.2.7 PAVEMENT SECTION WITH POLYMER BLEND RESIN (I.E., DUST

CONTROL) (FC-2, FC-5)

Aggregate and dirt road pavement sections treated with polymer blend resin can be an effective technique for dust control and increasing the CBR of dirt roads. For dust control treatments, the polymer blend is mixed with aggregate and placed on compacted soil sub-base material. An armor coat, consisting of a polymeric emulsion, is then sprayed on the compacted surface course and allowed to cure. If the armor coat is mixed on-site, a water source will be required. If access to water is a concern, the armor coat can be mixed off-site and then applied to the surface. For areas where native material CBR is low, the polymer blend resin can be mixed with the soils to increase the sub-grade CBR. Placement of polymer blend resin, suitable for FC-2 and FC-5 road types, shall be limited with respect to the steepness of the patrol, maintenance or access road profile grade. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which polymer blend resin should be placed based on industry standards and equipment capabilities.

Inspections are required bi-annually. Repairs of potholes and worn areas require full depth repairs and re-application of the polymeric emulsion topcoat is required for dust control.

1.2.8 PAVEMENT SECTION WITH CELLULAR CONFINEMENT OR

MECHANICAL CONCRETE (FC-2, FC-3 AND FC-5)

Cellular confinement or mechanical concrete is recommended for soft soils with low CBR, such as sand or silt roads on which thick, sinking material makes driving difficult or impossible. Cellular confinement consists of a three-dimensional, multi-celled structure, similar to a honeycomb, in a mat form. Loads are distributed laterally and vertical deflection is reduced. Construction requires anchoring at regular

Chapter 1 – Road, Bridge & Signage Design Standards 1-13 intervals and backfilling the cells with approved materials, such as on-site fill, imported fill or aggregates.

Compaction should be performed with a roller or lightweight compaction equipment. Mechanical concrete, similar to cellular confinement, utilizes larger cells, such as used tires with the side walls removed, placed adjacent one another. The cells are then filled with crushed aggregate which together with the cells forms the hardened road sub-base. Prior to selecting cellular confinement or mechanical concrete, a determination should be made on the source of the fill material within the cells and whether it can be acquired on-site or will be required to be shipped in from off-site. Regardless of the system selected, an aggregate surface layer of at least 4 inches should be placed above the cellular confinement or mechanical concrete. Cellular confinement and mechanical concrete are good for urban, rural, and mountainous locations and are easy to transport and install. Cellular confinement and mechanical concrete are suitable for all road types but are recommended for FC-5 roads in particular. Placement of cellular confinement and mechanical concrete shall be limited with respect to the steepness of the patrol, maintenance or access road profile grade. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which cellular confinement and mechanical concrete should be placed based on industry standards and equipment capabilities. General specifications for cellular confinement are provided in Appendix A, Standard Specifications, Cellular Confinement Reinforcement. Mechanical concrete is currently a registered trademarked item, therefore a draft vendor specification that outlines materials and execution is provided in Appendix A, Standard Specifications, Cellular Confinement Reinforcement for consideration by the designer.

Figure 10 - Cellular Confinement

Figure 11 – Mechanical Concrete

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Maintenance for both cellular confinement (Figure 10) and mechanical concrete (Figure 11) requires bi-annual inspection and blading of the surface material to remove any ruts or wash boarding. New material should be added every two years or as needed to maintain the 4 inches of gravel surface material.

1.2.9 ARTICULATED CONCRETE MAT PAVEMENT SECTION (LWC)

Articulated concrete mats (Figure 12) are typically used for LWC but can also be applied as a road surface in areas susceptible to significant erosion. Articulated concrete mats are a flexible, interlocking matrix of machine-compressed, cellular concrete blocks of uniform size, shape, and weight used for hard armor erosion control. These blocks are laced longitudinally with galvanized steel, stainless steel, or polyester revetment cables to provide ease of handling and rapid installation. Each concrete block unit shall have a compressive strength of 3,000 psi. Mats vary in dimensions but are typically 8 feet wide. Articulated concrete mats are excellent for urban, rural, and mountainous locations due to its ease of transport and installation. Mats are pre-assembled so there is no time limit on placement. In addition, there is no water or mixing requirements beyond what is required for subgrade preparation. Placement of articulated concrete mats, suitable for FC road types, shall be limited with respect to the steepness of the patrol, maintenance or access road profile grade. See Section 1.4.3.1, Profile Grades, for maximum profile grade to which articulated concrete mats should be placed based on industry standards and equipment capabilities. For general articulated concrete mat specifications, see Appendix A, Standard Specifications, Articulated Concrete Mat. For general articulated concrete mat details, see Appendix D, Miscellaneous Details.

Maintenance requires bi-annual inspections, but for installations in washes, the surface should be inspected after any major storm event. Debris should be swept from the blocks, and any backfill materials should be replaced.

Figure 12 - Articulated Concrete Mat

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Section 1.3 ROAD CROSS SECTION DESIGN STANDARDS

The typical cross section for patrol and maintenance road new construction or improvements shall be two lanes and 20 feet wide. Patrol road shall include 2-foot wide shoulders on each side. Based on project specific operational need, a 10-foot wide safety shoulder may be placed on the south or “border” side of the patrol road. When road widths need to be reduced, shoulders can be removed when determined it is safe to do so.

Reductions in road widths and removal of shoulders shall be determined during the pre-solicitation site visit on a project-by-project basis or as approved by CBP during the design phase.

Figure 13 - Patrol Road Typical Section (20 Feet Wide Road)

The typical cross section for access road new construction or improvements shall be 12 feet wide and have pull outs spaced based on sight distance and operational need in order to provide room for passing or parking for foot pursuit. At curves and blind spots where sight distance for on-coming traffic is restricted, the access road shall widen to 16 feet.

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Figure 14 - Access Road Typical Section (12 Feet Wide Road)

All patrol, maintenance and access roads, associated shoulders, foreslopes and backslopes shall be cleared and grubbed prior to construction of the roads. Final grading shall allow storm water run-off to drain away from the wall and other TI except at LWC locations where natural drainage patterns convey storm water runoff toward the wall and other TI. Roadside cut and fill slopes shall comply with the recommendations provided in Section 1.3.3, Foreslope and Backslope. See Figures 13 – Patrol Road Typical Section (20 Feet Wide Road) and Figure 14 – Access Road Typical Section (12 Feet Wide Road) for examples of typical road sections for a patrol road and an access road. Road cross section final design and preparation of construction documents shall be the responsibility of the Designer of Record (DOR) based on the minimum criteria and code requirements established herein.

1.3.1 CROSS SLOPE

In general, whether the road is crowned or superelevated, all cross slopes shall be 2-4 percent. Cross slopes less than 2 percent or greater than 4 percent require CBP approval prior to proceeding with design.

Where roads are superelevated the design shall be completed to safely and comfortably negotiate horizontal curves (see Section 1.4.2.2, Superelevation, for superelevation guidelines) and to accommodate roadway drainage outlet conditions so to protect structures and TI. Access roads, which are typically one lane, shall be superelevated only. Crowning of access roads may be used where access roads are widened over considerable distances and drainage considerations recommend the use of a crown.

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1.3.2 SAFETY SHOULDER

Patrol roads may have an additional safety shoulder added to the road section as seemed necessary by CBP for specific project operational needs. If implemented, the safety shoulder, sometimes referred to as a drag road, shall be 10 feet wide and placed between the patrol road and the border wall along the international land border; and, between the patrol road and the edge of the enforcement zone along the international river border. Safety shoulders shall be constructed of compacted native material and shall have a cross slope of 2-4 percent. Prior to the start of all patrol road projects, the necessity of a safety shoulder shall be evaluated. Access roads typically do not require safety shoulders.

1.3.3 FORESLOPE & BACKSLOPE

Road foreslopes are the slopes beyond the road shoulder that contain the road section and embankment.

When a road is constructed entirely using fill, the foreslope transitions the road embankment back into natural ground. When a road is constructed using cut, the foreslope must be transitioned to a backslope and before it ties into natural ground. See Figure 15 – Foreslope & Backslope, for an illustration of the two slopes.

Figure 15 – Foreslope & Backslope

The target slope range for the foreslope or backslope should be 4:1 to as steep as 2:1. The final foreslope and backslope design is contingent on-site specific conditions in conjunction with geotechnical recommendations. If slopes steeper than 2:1 are attainable due to on-site soil characteristics such as, but no limited to, rock or stiff material; or, if by use of structural enhancements such as, but not limited to, geogrid or soil cement the slopes can be steepened if agreed to by CBP. The requirements and recommendations for all foreslopes and backslopes shall be clearly outlined by the professional engineer (PE) responsible for the geotechnical recommendations for the project.

Where the maximum allowable foreslope or backslope will not intersect with the existing ground line within the limits of the easement, or within 30 feet of the centerline of the road construction, an earth retaining structure shall be used. Earth retaining structures such as, but not limited to, mechanically stabilized earth (MSE) walls, cantilevered or gravity retaining walls, or soil nail walls shall be selected based on the type of construction needed (i.e. top-down or bottom-up construction), constructability, availability of local materials and project costs.

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1.3.4 GUARDRAIL

Guardrail is typically needed along roadway foreslopes to prevent vehicles from accidentally leaving the roadway and putting driver safety in jeopardy.