10-Plan for the Rehabiliation, Restoration and Renewal 09252019.pdf

Big Creek Greenway Multi Use Trail

Phases 1, 2, and 3

September 25, 2019

A Plan for the Rehabilitation, Restoration, and

Renewal of the Greenway, Phases 1, 2, and 3

Task I: Defining the Problem

Prepared For:

Prepared By:

A Plan for the Rehabilitation, Restoration, and Renewal of the Greenway, Phases 1, 2, and 3

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | i

CONTENTS

1. Executive Summary

2. Introduction

3. Site Observations

A. Structural Failure

B. Material Deterioration

C. Handrail

D. Damaged Steel Truss Span

E. Erosion

F. Siltation

G. Slab Settlement

H. Mildew/Fungi

4. Discussion Related to Observations

5. Elements of the “Improved” Greenway

6. Recommendations

APPENDIX 1 Inspection Report (including photo library) and Detailed Layout

APPENDIX 2 Construction Plans

APPENDIX 3 Hydraulic

APPENDIX 4 Work Product

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | ii

List of Figures

1. Big Creek Greenway Master Plan

2. Greenway Phases 1, 2, and 3

3. Boardwalk Terminology

4. Elevated Boardwalk Terminology

5. As Built Boardwalk Typical Section

6. As Built Railing Detail

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 1

1. Executive Summary

Big Creek Greenway in Forsyth County is a valuable County asset and an important amenity for the residents. The Greenway is exhibiting excessive problems that have led to the need for extraordinary efforts by the maintenance staff. The primary problem is due to deterioration and isolated failure of the timber boardwalks.

This report recommends multiple processes for rehabilitation/repair and/or replacement of the boardwalk in such a way as to maximize the availability of the facility to the public.

After consultation with County staff, this report will become the basis for continued work in developing the processes and procedures as well as repair details and construction packages.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 2

2. Introduction

Big Creek Greenway in Forsyth County is a multi-use trail that is planned to run south - north across the length of the county, beginning at the County line near MacFarland Parkway and McGinnis Ferry Road and ending near Cumming. The trail primarily follows the alignment and the flood plain of Big Creek northwards towards its source.

When completed, the Forsyth County section of the trail will connect to the trail running through Alpharetta, offering significant potential for regional connectivity. The trail is designed to provide recreational (walking, hiking, bicycling) opportunity as well as improved mobility. (see figure 1)

The Greenway is predominately located along the creek banks and/or with the flood plain of Big Creek, and its design and construction required significant lengths of elevated boardwalks as well as several steel truss bridge crossings of the creek.

The trail has been planned and built as a series of connected phases. Phases 1, 2, and 3 of the trail were built circa 2007 from the southern section of the trail in the County and running between MacFarland Parkway and Bethelview Road for a length of approximately 7 miles (see figure 2). Phase 4 was built circa 2015 and extended the Greenway in a northern direction from Bethelview Road to Johnson Road. Phase 5 construction is anticipated to begin within the next year and continues the Greenway from Johnson Road to approximately SR 20.

The opening of Phases 1, 2, and 3 provided a valuable amenity to the residents of the county and was (and remains) popular and heavily used by a broad cross section of users. The consistent 12’ width, use of timber throughout for boardwalk, and the low elevation of the boardwalk provide an attractive appearance. It is a unique facility because of the amount of boardwalk and the use of a low edge rail, rather than a barrier railing for that is used for the boardwalk and located close to the ground. The winding alignment cuts an attractive swath through the hardwood timbers of the flood plain, providing the opportunity for a pleasant and tranquil escape from the urban surrounds.

After 10 years of service however, the trail, and particularly the boardwalk sections, are showing signs of deterioration and are in need of repair. County staff are spending considerable resources to maintain the trail in a safe and operable condition. The Forsyth Department of Parks and Recreation commissioned a study of the Phases 1, 2, and 3 sections to determine the extent of the problems, the prognosis for the future, and the potential for repair and rehabilitation. The goal of the study is the development of a robust methodology for management of the facility including effort by both County staff and private contractors. One element of the work is the development of plans and documents leading to a rehabilitation contract to be completed by a private contractor.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 3

Figure 1 Big Creek Greenway Master Plan

This report is Task 1 of the overall commission and “Defines the Problem”. After County staff review and discuss the report, it will be revised to stand as the basis for the Task 2 work which is to prepare construction schedules, plans, cost estimates etc. – all leading to the full rehabilitation of Phases 1, 2, and 3 of the trail.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 4

3. Site Observations

H&L Engineers visited the site during June and July to walk the entire length of the Phase 1 section of the trail (hereafter “The Project”) and to record key observations. They were assisted throughout by County staff familiar with the various issues. Figure 2 shows a general mapping of the length of the project, noting each deficiency by color code. Observations are introduced and discussed below.

Appendix 1 contains our full inspection report including detailed mapping and a library of photographs.

Figure 2 Greenway Phases 1, 2, and 3

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 5

A. Structural Failure

Structural failure was observed at several locations. This failure was typically found in the post crossheads and was typically at a location where there was loss of section due to rotting.

At some locations, stringers and deck boards showed structural failure, but such failure is typically related to rotting of the element.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 6

B. Material Deterioration

There are a number of locations where the wooden elements of the boardwalk are heavily rotted.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 7

C. Handrail

At some locations where the boardwalk rises to clear obstacles or to approach a bridge, the design transitions from the low “curb” barrier into a full handrail. At several locations, the handrail appears loose and unstable.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 8

D. Damaged Steel Truss Span

Between mile markers 1.1 and 1.2 and just south of GA 400/US 19, the trail crosses the creek on a concrete deck, steel, through truss bridge. The top (compression) chord of the bridge is damaged and bent out of plane due to impact from a falling tree.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 9

E. Erosion

The trail has eroded at sporadic locations and in some areas has undermined the concrete post supports, leaving the boardwalk only loosely supported.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 10

F. Siltation

At some locations, the trail is subject to silt build up after flooding. The silt inundates the boardwalk and, in some areas, has built up to the level of the boardwalk decking.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 11

G. Slab Settlement

Slab on grade has settled significantly at some locations, leaving permanent low spots and poor ride quality.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 12

H. Mildew/Fungi

The trail is typically “buried” deep in forest, with heavy shade and high humidity leading to an aggressive climate for development of mildew and fungi.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 13

4. Discussion Related to Observations

4.1 Structural

4.1.1 Terminology - Low and Elevated Level Boardwalk

The basic configuration of the boardwalk for Phases 1, 2, and 3 are similar. The low level boardwalk is designed for maximum clearance of 30” from the ground to top of deck.

Figure 3

At some locations, typically to approach bridges over the creek or to cross obstacles along the trail, such as drainage gulleys and creek tributaries, the boardwalk elevates up to 8’ off the ground.

Figure 4

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 14

4.1.2 As Designed and As Built Condition

4.1.2.1 Phase 1 as Designed

For Phase 1, the design plans are included in Appendix 2.

The design was based on Southern Pine, #2 or better, pressure treated lumber. Design live load was 85 psf. Piers were designed for 2000 psi concrete using pea gravel grout and supported on allowable soil bearing pressure of 2000 psf. Piers are shown at 1’0” diameter. Design was per the IBC 2000 code with 2002,2003, 2004, and 2005 Georgia State Amendments. The detailed specification follows:

Design Criteria

A. Design live load – 85 psf

B. Timber framing and fastener design

(National design specification for wood construction, 2001 ed.)

C. Design wind load – 50.0 psf

(Guide specifications for the design of pedestrian bridges – 1997, AASHTO)

D. Design per IBC 2000 with 2002, 2003, 2004, and 2005 GA State Amendments

E. Assumed allowable soil bearing pressure – 2000 psf

4.1.2.2 Phase 1 As Built

These are several major differences between as designed and as built. These include:

The design shows the stringers framing into the crosshead (presumably using a joist hanger but that is not detailed). As built the stringers are supported on the cross heads. The consequence of this is that the low chord of the as built boardwalk is some 8” closer to the ground than was shown in the design (assuming 2x8” stringers).

The stringers are set at about 2’ c/c as built rather than the 1’0” c/c shown on the design plans.

4.1.2.3 Phases 2 and 3 As Designed

For Phases 2 and 3, the design plans were modified as follows:

(See Appendix 2, Phase 2 & 3)

The design was based on a revised material specification:

“All posts and beams shall be 0.4 Pressure Treated”

“All wood members shall be 0.4 Pressure Treated”

Piers were to be designed for bearing on allowable soil bearing of 3000 psf.

Design live load was 110 psf.

The stringers were detailed at approximately 2’0” c/c and were in the plane of the cross leads as for the Phase 1 design. (i.e. hangers required)

Piers are shown at 1’6” diameter in “Dry Upland Areas” only and as 2’4” in “Flood Areas Only”.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 15

4.1.2.4 Phases 2 and 3 As Built

Phases 2 and 3 as built condition appears essentially identical to Phase 1.

4.1.2.5 Phase 4 As Designed

The design details for Phase 4 (Appendix 2, Phase 4) appear to match exactly the details for Phases 2 and 3 except that the design loading was modified to include a 5000 pound axle load in addition to the 110 psf pedestrian load. There is a “zoomed detail” which appears to show the stringers supported on the cross head beam with the crosshead doubled up, but the main detail does not show this.

4.1.2.6 Phase 4 As Built

Phase 4 as built condition appears to be essentially identical to Phases 1, 2, and 3.

4.1.3 Rating - As Designed and As Built

4.1.3.2 As Designed

We do not have sufficient detail to rate the boardwalk from the design plans.

4.1.3.2 As Built

The typical span length of the as built boardwalk is 8’0” between posts. This dimension varies.

Consequently, we have rated the bridge for 6’0”, 7’0”, 8’0”, and 9’0” span lengths. The rating value is the live loading that generates stresses in any element of the structure equal to allowable.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 16

The absolute rating is the live loading that generates stress in any element of the structure equal to 90% of stress at failure.

Each element of the boardwalk is separately rated - deck, stringers, crossheads posts, and piers.

The “typical detail” observed in the field is drawn in Figure 5, and these details are used in the rating.

Figure 5

Figure 6

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 17

Table 1A

Pedestrian Load Rating

Deck (psf) Stringers (psf) Crossheads (psf)

6' Span Allowable 1105 92 19

Ultimate 4450 355 105

7' Span Allowable 1105 65 15

Ultimate 4450 260 88

8' Span Allowable 1105 48 12

Ultimate 4450 198 77

9' Span Allowable 1105 36 10

Ultimate 4450 155 67

All posts are rated at an allowable axial load of 12,300 lbs. All piers are rated at an allowable 2000 psf bearing capacity.

Table 1B

Posts (lbs) Piers (psf)

6' Span Design Load 3379 4302

Allowable 12300 2000

7' Span Design Load 3967 5051

Allowable 12300 2000

8' Span Design Load 4490 5717

Allowable 12300 2000

9' Span Design Load 5068 6453

Allowable 12300 2000

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 18

We also checked for load capacity based on the vehicles used by the County to access along the boardwalk.

Table 2

Vehicle Load Rating

6' Span 7' Span 8' Span 9' Span

Decking Allowable (lbs) 479 479 479 479

Ultimate (lbs) 1912 1912 1912 1912

Stringers Allowable (lbs) 556 463 391 333

Ultimate (lbs) 2158 1692 1428 1216

Crossheads Allowable (lbs) 996 840 720 626

Ultimate (lbs) 3764 3069 2633 2287

Ultimate and allowable loads are wheel loads applied to result in maximum stresses. Ultimate capacity assumes 0.9 of the yield strength for the consideration of emergency vehicles. The typical wheel configurations used to determine maximum stress are drawn below.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 19

4.2 Material Deterioration

The wooden elements of the boardwalk are showing deterioration, primarily due to rotting but also in the form of cracks and splits. In order to understand the significance of loss of section on the ability of the boardwalk to sustain loads, we reran the analysis completed and reported in Table 1 but using reduced section properties based upon varying amount of loss of section.

The results are reported in Table 3.

Load capacity for the stringers and crossheads was also checked assuming a reduced member section.

Table 3

Pedestrian Load Rating

Deck (psf) Stringers (psf) Crossheads (psf)

1/8" Loss

1/4" Loss

1/8" Loss

1/4" Loss

1/8" Loss

1/4" Loss

6' Span Allowable 937 774 80 68 18 17

Ultimate 3737 3089 311 270 101 98

7' Span Allowable 937 774 56 48 14 13

Ultimate 3737 3089 228 197 85 82

8' Span Allowable 937 774 41 35 11 10

Ultimate 3737 3089 173 150 74 72

9' Span Allowable 937 774 31 26 9 8

Ultimate 3737 3089 136 118 65 62

The ratings are informative. For example, in Table 1A, the critical rating value is that the crosshead as built has a very low design capacity equivalent to only 12 psf and an anticipated failure capacity of 77 psf.

We note that the design loading of 85 psf is conservative for a boardwalk. That is equivalent to eight 200 pound people standing along one 8 foot stringer - extremely unlikely. (Or forty 200 pound people congregating on a single span.)

Similarly, Table 2 indicates that a total vehicle wheel load of 1428 pounds would fail the stringer.

This is equivalent to a 5700 lb. vehicle. This capacity is correspondingly reduced if section loss is considered.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 20

4.3 Handrails

Handrails for boardwalks are notoriously difficult to anchor because of the prying action that can potentially overcome the minimal lever arm resistance offered by their connection into the fascia stringer.

We calculated the resistance offered by the detail as built and compared that to the likely lateral load at top of rail. The detail is sufficient but clearly is fatigue sensitive, with softening at the bolt washers ultimately allowing movement which is then exaggerated by repeated loading.

There are some locations of trail such as the Cattle Bridge boardwalk section north of Atlanta Highway between mile posts 0.2 and 0.3 that are currently elevated (and hence require a handrail) that can be potentially rebuilt as low profile or even at grade boardwalk.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 21

4.4 Steel Truss

We have not yet obtained as built details for the truss as provided between mile markers 1.1 and

1.2 and just south of the GA 400/US 19 crossing. We think it is important to straighten the compression member (top chord) of the truss to restore full load capacity.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 22

4.5 & 4.6 Erosion and Sedimentation (Creek Hydraulics)

We have attached the hydraulic data including FEMA profiles (Appendix III). We took the profile built along the length of the creek and superimposed the trail profile as best determined from the plans and our observations. The profiles are verified against the elevation quoted on the bridge sheets for each of the creek crossings and versus the observation made by Parks & Rec personnel that the trail is inundated when the creek reaches a depth of 7’. The work product is best reviewed on the separate roll plot. It is apparent that the trail is relatively low when compared to predicted flood elevations at relatively common return year storms. Given that the storm elevations will continue, the emphasis should be on ensuring no rise in the creek in future years and management of factors that lead to erosion and sedimentation and compound the problems of recovering from flood events.

It is apparent that one consequence of the high water elevations is that some lengths of the trail on boardwalk now cross permanent ponds that were simply not present at the time of construction. This has the potential to impact the choice between replacement and rehabilitation and/or to indicate a preferred funding source at such environmentally sensitive areas.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 23

4.7 Mildew/Fungi

The significant areas of mildew/fungi observed which promote deterioration of the lumber are directly related to the limited number of hours that section of boardwalk is in sunshine.

Obviously, all substructure components stay in the shade and close to the ground in permanently damp conditions.

In many areas, the deck boards stay in the shade. This situation can be improved by enhanced trimming/clearing of the tree canopy. The deck board condition is not helped by the boards having been installed “edge to edge” at many locations, restricting the ability of the deck to drain freely.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 24

4.8 Slab Settlement

With no significant live loads or impact loads to drive the slabs down (as is often observed at approach slabs for highway bridges), it is apparent that the settlement is more related to long term consolidation of the subgrade beneath the slabs. In turn, this may be due to the permanently moist condition of the subgrade.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 25

4.9 Summary

The attached sheets compare (rate) structural and other characteristics of the various boardwalk sections. The tables give a good understanding of the relative condition of the boardwalk sections.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 26

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 27

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 28

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 29

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 30

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 31

5. Elements of the “Improved” Greenway

Based on field observations and discussions with the County Parks & Recreation staff, we have determined that the rehabilitated greenway should strive to include the following characteristics:

A. Be structurally adequate for the anticipated loading, including pedestrian (cyclists, families, and runners), maintenance vehicles, and emergency vehicles (and loading should be realistic). County staff have provided a list of vehicles that could potentially require access along the trail. The list follows at the end of this section.

B. Be durable but not “maintenance free”. Ensure minimal maintenance with maintenance requirements identified and acceptable to staff and with a high level of certainty of life cycle expectancy.

C. Provide high quality ride surface with minimal trip hazards

D. Be set at an elevation that is sensibly high over anticipated flood elevation without changing visual characteristics

E. Be based on a construction scheme that considers access and potentially the need to schedule construction to begin at access points and to proceed up and down the trail with access provided along the renovated structure

F. Retain all elements of the existing structure wherever possible and cost effective

G. Find the right balance between replacement and rehabilitation

H. Consider all potential material choices but respect existing aesthetics

I. Meet current code and standard or provide a “design exception” or “variance”.

J. Be wider (16’ out to out) than the existing section (12’ out to out)

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 32

Equipment and Vehicles Access Needed on Greenway

Parks

ATV/UTV

• John Deer Gator-TS 4x2

• Polaris 4-Wheeler- Sportsman EXT

• Kawasaki Mule-SX 4x4 FI

Tractor/Skid Steers/Mowers

• New Holland 16LA

• Kubota- 2301B

• Bobcat- T650

• Ditch Witch- SK800

• Hustler- Super Z 60”

Sheriff’s Office

• Kawasaki Mule- 4010 2x2

Fire Dept.

• Yamaha Golf Cart Modified mini ambulance

Vehicles

• Ford F150 Single Cab

• Ambulance (?)

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 33

6. Recommendations

1. The section of boardwalk within “Inspection Section 1” (McFarland Parkway to Union Hill Road) on sheet 7, figure 2, from approximately mile marker 0.2 to 0.6 rates poorest in all categories. It is also the oldest (first constructed) section and is close to a major trailhead and hence sees a lot of traffic (pedestrian and vehicular).

Another section of concern is within “Inspection Section 2” (Union Hill Road to Atlanta Highway) on sheet 7, figure 2 from approximately mile marker 0.1 to 0.8. This section is closest to Fowler park and hence sees the most traffic (pedestrian and vehicular).

In our opinion, neither of the structures in these areas cannot be rationally rehabilitated because of the advanced deterioration of the substructure elements, and they should be replaced.

We recommend proceeding in Phase 2 of this study with the design of a replacement boardwalk. The design should consider reasonable design loading for pedestrian, vehicular, and emergency vehicles. The design should be “modular”, allowing the potential for removal of sections of boardwalk as well as boardwalk complete. The design must consider durability and life cycle.

1. Any reconstruction should consider the optimum elevation to set top of deck. This elevation should be as high as possible to elevate the structure above flood water as far as possible but low enough to retain the “low curb” edge detail which is a strong element of character of the facility.

2. The trail is heavily used. Closing portions of the trail for extensive periods of time to facilitate construction will not be well received by the public. Major repair projects should consider the options for safely allowing the trail to pass the work zone (local or site detour). These details should be investigated and developed in Phase 2 of this study for inclusion in the construction plans. R/W restrictions may dominate this element of the work. The development of best options for completing work with minimal impact to trail users is vitally important.

3. The major reconstruction work should be bid out to qualified private contractors. Use of private contractors for elements of the trail will free up Parks & Recreation staff to focus on routine maintenance elsewhere.

4. Any redesign of the boardwalk should consider retaining the current visual aesthetic of the trail and particularly the boardwalk elements.

5. The design of the trail should consistently respect current code requirements with agreed design exceptions and variances as necessary.

6. The current trail width of 12’ between face of curbs and railings is not adequate, especially on the weekends and holidays and if maintenance vehicles are on the trail.

7. The current railing details are inadequate (especially at the Cattle Bridge boardwalk section north of Atlanta Highway between mile post 0.2 and 0.3). In Phase 2, a new detail should be developed for possible inclusion in an early construction package.

8. The early construction package should be scheduled to avoid work during likely periods of high water. Therefore, the ideal target date for construction is May through November.

Based on this, the target let date for an early construction contract is around March/April

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 34

2020. Construction plans and specifications should be prepared and submitted by January/February 2020.

9. In coordination with Parks and Recreation and Forsyth County Emergency Services, a decision should be made on required vehicular (wheel) loads to be considered in design for maintenance and emergency vehicles (in the case of the emergency vehicles, these loads can be considered as special overloads). Finding the right balance between ensuring that the trail provides access for a rational selection of safety and maintenance vehicles and the excess cost that comes with “over designing” the structures is critical.

10. The hydraulics analysis for the creek should be continued to identify potential options for eliminating future changes in storm water profiles and to reduce the potential for erosion and sedimentation. Such options could include recommendations for green initiatives within the watershed of the creek, to hold water within the watershed and to slow its release into the creek and/or options for stream bank protection to reduce erosion of the creek bank (which lends to siltation problems).

11. The sections of slab on grade that are showing evidence of settlement should be repaired.

This work (as it relates) to any early construction contract should be based on the worst areas just south of Majors Road near mile markers 1.3 and 1.4, which are leading to tripping hazards and/or localized ponding. Options for repair should include consideration of building boardwalk to replace the slab on grade (where drainage changes have led to the area being repeatedly inundated), mud jacking (probably limited to areas where settlement is less severe and subsoils are adequate) and removal of the existing slab, and treatment/improvement of the subsoils and replacement with a new, possibly lightweight slab.

12. Alternate materials that should be considered for the new design should include:

• Concrete Piers vs. helical anchors

• Substructure Elements - wood vs. concrete vs steel

• Deck – wood vs. composite vs. concrete

(Note that the choice of materials should include consideration of construction cost, life cycle cost, aesthetics, durability and maintenance requirements, resistance to fungi/algae build up, and traction for walkers, runners, and bicyclists).

13. Construction Depth – There is an advantage in developing minimum construction depth solutions because they offer the most separation between ground and structure. For timber substructure options, this is clearly a benefit, but for all options it offers the most capability to accept ground profile changes over time due to siltation and fluctuations within the creek flood plain.

14. We recommend early consultation regarding any potential environmental permitting restrictions associated with rehabilitation work in the flood plain. In particular, the areas which now appear permanently inundated should be studied. Environmental concerns may favor solutions such as the use of helical piles which do not require ground disturbance activities.

15. The bent rail of the steel truss bridge at mile post 1.1 and 1.2 and just south of the GA 400/US 19 crossing is a concern. This rail serves as the compression chord of the truss and is a non-redundant member. One early task is to develop repair plans for this component and consider an immediate task to shove up the chord.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 35

Pending the repair, we recommend posting the bridge as “20 persons max”.

Other options should include the possibility of using of “exotic” woods - cedar, cypress, redwood, or black locust, and proprietary systems such as Permatrack.

16. Immediate Rehabilitation- In addition to planning a replacement project for late Spring 2020, we recommend an immediate contract for enhanced maintenance to “get ahead” of the problems identified in the worst areas. This contract would be on a unit price basis with the contractor selected on the basis of a specific minimum and maximum amount of replacement of deck boards, stringers, and crossheads at locations identified in the field.

Basis of Cost Estimates/Opinions

There are several options for pricing the various maintenance requirements. At the concept level, we are using unit prices for completed components (typically spans of boardwalk) rather than a table of unit prices) As designs develop, these concept levels will be refined.

All options are compared for the life cycle costs assuming an overall desirable life cycle of 50 years. The component level for boardwalk comparisons will be 24’ of boardwalk. This will allow timber spans of 6 and 8’ to be compared with other materials arranged in 12’ or 16’ span lengths. Selective removal and replacement of spans within a run of boardwalk is feasible at this length.

The attached sheet lists the various items for which costs are being developed.

Detailed work product behind the estimate numbers is included as Appendix 4.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 36

Rate of Deterioration of Lumber

Pressure treated lumber (specifically Southern Pine No. 2 or better) treated with Alkaline Copper Quaternary Preservative with a retention of 0.60 for in ground use (posts) and 0.25 for above ground use (substructure framing and deck) is advertised to have a design life of 40 years. The original design plans state that “The manufacturer shall provide 10 year warranty for all pressure treated lumber”.

Articles related to design life caution that moisture entering the wood from splits or cracks will tend to reduce the design life. Installation in a damp, shaded environment, close to the ground will allow the growth of mildew and fungi which will impact expectancy.

Saw cutting of the lumber creates an exposed end for penetration of moisture - such raw cuts should be treated with sealant during construction. There is more discussion on the validity of placing deck boards bark side up to eliminate cupping and retention of moisture.

The deck boards should be installed with separation between the boards to facilitate free drainage of the deck.

In the field, it is apparent that for a combination of reasons, the lumber has not achieved the promised life expectancy.

Research is continuing in an endeavor to develop a realistic life cycle deteriorative curve. This will be vital in developing a year by year plan for renovation and replacement of the existing structures.

In Phase 2 of this report, deterioration curves will be developed and published.

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 37

Recommended Design Criteria/Code Compliance

• Trail o Accessible Public Rights-of-Way, Planning and Designing for Alterations, Public Rights-of- Way Access Advisory Committee, 2007 o Designing Sidewalks and Trails for Access, Part II of II: Best Practices Design Guide, FHWA, 2001 (Note: web HTML version incorporates corrections in the errata sheet) o FHWA Bicycle & Pedestrian Program – Design Guidelines web page, Federal Highway Association (FHWA) http://www.fhwa.dot.gov/environment/bicycle_pedestrian/guidance/design_guidance/ o Guide for the Development of Bicycle Facilities, AASHTO, 2012 o Guide for the Planning, Design, and Operation of Pedestrian Facilities, AASHTO, 2012 o Manual for Traffic Control Devices (MUTCD), 2009 o Pedestrian and Streetscape Guide, GDOT, 2019 o Proposed Guidelines for Public Rights-of-Way (PROWAG), United States Access Board, o Urban Bikeway Design Guide, National Association of City Transpiration Officials (NACTO).

(Refer to the FHWA document Bicycle Facilities and the Manual on Uniform Traffic Control Devices for the status of specific bicycle facilities in FHWA’s MUTCD) o Urban Street Design Guide, NACTO, 2013

• Structural o AASHTO LRFD Pedestrian Bridge Guide Specification, 2009 o AASHTO LRFD 7th Edition, 2014 o International Building Code (IBC), 2012 o National Design Specifications, American Wood Council, (2009 Edition) o Standard Specifications for Highway Bridges, AASHTO (17th Edition, 2002) o Steel Construction Manual, AISC (15th Edition, 2017)

• Stormwater/Erosion o Georgia Stormwater Management Manual Volumes 1 & 2 (Blue Book), 2016 http://www.fhwa.dot.gov/environment/bicycle_pedestrian/guidance/design_guidance/

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem P a g e | 38

APPENDIX 1 Inspection Report (including photo library) and Detailed Layout

X

X

X

X

X X

X X

XX

RGM

RGM

X

X

X

X

X

X X X

X

RGM

X X

X

X

RGM

RGM

RGM

RGM

RGM

RGM

RGM

X X

X X

X X

MAIL

X

X

X

X

X

X

X

X

X

X

X

X

X

X

RGM

RGM

S I

D E

W A

L K

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X X

X X

X

X X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X X

X X

X X

X

X

X

X

X

X X

X X

X

X

X X

X X

X

X

X

X

X

X

X X

X

X

X

X

XX

FORSYTH COUNTY

BIG CREEK GREENWAY DETAIL MAP

APPENDIX 1

S H I L

O H

R

O A

D

R O

N A L

D

R E

A G

A N

B L

V D

G A

U S

GA 400/US 19

SHIL

OH ROAD

SHILOH ROAD

UNION HILL ROAD TRAILHEAD

BIG CREEK GREENWAY

M A

R S

H I L

O

A D

A T L

A N T

A

G H

W A

Y

FOWLER PARK

MCFARLAND PARKWAY

S T

O N E

Y

P

O I

N T

R

O A

D

C A S T L E B E R R Y

R O A D

MAJ

OR

S

ROAD

MAJ

OR

S

ROAD

POST ROAD

POS

T R

OAD

B E T H E L V I E

W

R O A D

STA 9+50.00

MCFARLAND PARKWAY TRAILHEAD

BEGIN PROJECT

STA 369+46.29

BETHELVIEW ROAD TRAILHEAD

END PROJECT

U N I

N

A D

BRIDGE

14+35.00 15+80.00

19+30.00 20+40.00

22+50.00 43+45.00

46+65.00 51+30.00

54+90.00 72+85.00

84+90.00

START END

STRUCTURE TYPE STATION

74+56.00 75+36.00

121+85.00

2 131+05.00 131+85.00

131+85.00 133+04.00

133+04.00 133+84.003

133+84.00

165+90.00

165+90.00 166+70.00

166+70.00 175+20.00

178+55.00 178+70.00

181+05.00 181+35.00

183+70.00 183+90.00

207+50.00 208+50.00

14 225+50.00

227+50.00

254+00.00 261+00.00

269+50.00 288+00.00

296+75.00 297+55.00

323+30.00 323+90.00

325+75.00 338+50.00

344+80.00 353+60.00

353+60.00 354+20.00

354+20.00

5 267+60.00 268+30.00

BOARDWALK

CROSSING

CATTLE

229+60.00

APPROXIMATELY

233+55.00

APPROXIMATELY

TRAILHEAD

BETHELVIEW RD

CLOSEST TO

BOARDWALK

BOARDWALK

92'-0" LONG

APPROXIMATELY

(NOT ON PLANS)

(NOT ON PLANS)

356+00.00

APPROXIMATELY

TIME$$$

$USER$

DATE$$$ $PRF8$

GR1EDG11/30/20114/30/2015

PROPERTY AND EXISTING R/W LINE

REQD R/W LINE

TEMPORARY EASMT LINE

REVISION DATES

DRAWING No.CHECKED:

BACKCHECKED:

CORRECTED:

VERIFIED:

DATE:

DATE:

DATE:

DATE:

P.I. No.

$DGN$

PROJECT CENTERLINE

PARK

FLOODPLAIN

STREAM EXTENTS

900 1800 3600

SCALE IN FEET

APPROXIMATE LOCATION OF MILE MARKER

+0

+0

5+

0 1

0+

0+

215+00220+00

225+00

0+

+00

+00

+00

+00

5+

0+

5+

0+

315+00

320+0

5+

0+

5+

0.1

0.2

0.3

0.4

0.5 0.6

0.7 0.8

0.9

1.1

1.1

1.2

1.3 1.4 1.5

1.6 1.7 1.8 1.9

2.0 2.1

2.2

0.1 0.2

0.3

0.4

0.5 0.6

0.7 0.8

0.9

1.0

1.1 1.2

1.3 1.4 1.5

1.6

1.7

0.1

0.2 0.3

0.4 0.5 0.6

0.7 0.8

0.9

1.0

1.1

1.2

1.3

1.4

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0 1.1 1.2

1.3

1.4

1.5

0.0

Big Creek Greenway Phases 1-3: Task 1: Defining the Problem

Site Inspection Memo:

The inspection was performed with two site visits. The first was on Thursday, July 25th, 2019, and the second on Wednesday, July 31st, 2019 to finish the remainder of structure/boardwalk. Heath & Lineback employees Ted Sparks and Patrick James performed the inspection, collected site observation data, and logged/organized the data.

Before performing the site inspection, a rating system and categories were determined (see section “4.9

Summary”). This rating system was used to evaluate all the existing boardwalk and bridge structures on the project areas. The boardwalks were separated by where they transition onto at-grade trail or bridge structure.

The first day of inspection was performed with a Forsyth County Parks and Recreation employee, Kyle.

Ted, Patrick, and Kyle used a utility task vehicle (UTV) to traverse the greenway while stopping at every tenth of a mile marker, at the beginning and end of each boardwalk section, where a section had visible damage/deterioration, and sections Kyle knew were problem areas. At every stop, the inspectors walked up and down the alignment on and off the side of the boardwalk inspecting the substructure and deck.

The sections covered on this day were from the Bethelview Road trailhead to Fowler Park and then from the Mcfarland Parkway trailhead to the Union Hill Road Trailhead.

The second day of inspection was performed by Ted and Patrick. There was not as much boardwalk to inspect, so Ted and Patrick walked the sections but utilized the same methodology as the first day. The remainder of boardwalk inspected on this day was from the Union Hill Road trailhead to Fowler Park.

Following this memo are the notes and pictures taken during the site visit.

Page 2 of 5 8/23/2019

Boardwalk Bridge Start End Structure Type Structural Deterioration (10) Rating Excess Mildew/Fungi (8) Rating Structural Damage (10) Rating Boardwalk Score

1 14+35.00 15+80.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Deck chipping and deterioration from constant sun exposure.

- No noticeable exceed mildew/fungi.

- No noticeable structural damage.

5 130.0

2 19+30.00 20+40.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Deck chipping and cracking.

- Post Crossheads are wet and stay wet.

There is no deterioration at this point though.

4.75

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 137.5

(Need to Re-Visit and Study Further)

22+50.00 43+45.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Approximately 75% of the stringers were starting to rot.

- Deck is rotting in sections. 3

- There is excess mold/fungi on the stringers.

- Water is building up and ponding on the wood deck.

- Excessive structural damage due to structural deterioration.

3 76.0

4 46+65.00 51+30.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Compromised Post Crosshead boards that are bowed excessively. Some boards are warped so bad they are now in the water or mud.

- The majority of the deck is rotted.

- Some of the 6"x6" "curb" boards are burning.

- Excess mold/fungi on the deck boards and some on the stringers.

- Excessive structural damage due to structural deterioration.

3 92.0

5 54+90.00 72+85.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- 6"x6" "curb" pieces are rotting.

- Minor deck issues, rotting boards, chipping, etc…

3.5

- No noticeable excess mildew/fungi.

- A lot of the post crossheads

(approximately 50%) were braced.

4 115.0

1 74+56.00 75+36.00 Prefabricated Steel Truss

- No structural deterioration other than the damage to the top chord.

- No noticeable excess mildew/fungi.

- The top chord of the truss was damaged by a tree falling. The tree bent the top chords well out of alignment.

3.5 107.0

Overall Section Rating

McFarland Parkway

Trailhead to Union Hill

Road Trailhead

6 84+90.00 121+85.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Multiple sections of rotted deck boards and stringers.

- The handrail was rotted and breaking.

- multiple locations of broken Post

Crossheads and stringers.

3.5

- Excess water ponding on boardwalk.

- Approximately 30% of the stringers have mold.

- A lot of the Post Crossheads

(approximately 50%) were braced.

- There was significant debris buildup along the side of the boardwalk. 3.5 94.0 107.36

2 131+05.00 131+85.00 Prefabricated Steel Truss with

Boardwalk Leading up to It

- There was a broken post crosshead on boardwalk leading up to bridge.

- Minor mildew/fungi.

4.5

- No noticeable structural damage.

5 126.0

7 131+85.00 133+04.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- There were a couple of broken deck boards.

- The deck needs replacement.

- Minor mildew/fungi.

- Water builds up on deck.

- No noticeable structural damage.

5 104.0

3 133+04.00 133+84.00 Prefabricated Steel Truss

- No noticeable structural deterioration.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 140.0

8 133+84.00 165+90.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

Boardwalk closer to the ground had a thicker Post Crosshead on the ground in lieu of vertical supports.

- Multiple areas of rotted deck boards.

- Multiple broken and rotted handrail pieces.

- Stringers are in the early phases of starting to rot.

- Multiple Post Crossheads rotting.

- Excess mold buildup on handrails and on top of stringers.

- Excessive leaf buildup on 2-3 sections that make boardwalk very slick and prevent it from drying out.

- Lots of standing water on the boardwalk.

2.5

- Broken Post Crossheads.

- Broken 6"x6" "curb" piece, likely from a tree falling on it.

3.5 85.0

4 165+90.00 166+70.00 Prefabricated Steel Truss with

Boardwalk Leading up to It

- No noticeable structural deterioration.

- Minor mold buildup on railings.

4.5

- Boardwalk leading up to the bridge was recently replaced and is in good condition.

5 136.0

9 166+70.00 175+20.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Multiple deck boards and railings are rotted.

- Chipping, cracking, and deterioration from sun damage.

3.5

- No noticeable excess mildew/fungi.

- 3 boards are popping up to create a tripping hazard. Likely from screws failing.

4 115.0

10 178+55.00 178+70.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Minor boardwalk cracking and deterioration from sun damage.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 130.0

Big Creek Greenway Structural Inspection McFarland Parkway Trailhead to Bethelview Road Trailhead

McFarland Parkway Trailhead

Union Hill Road Trailhead

Page 3 of 5 8/23/2019

Boardwalk Bridge Start End Structure Type Structural Deterioration Rating Excess Mildew/Fungi Rating Structural Damage Rating Boardwalk Score (Out of 5)

Boardwalk

Connection to

Fowler Park

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- No noticeable structural deterioration.

- Excessive water ponding on connection to the greenway side.

- No noticeable structural damage.

5 124.0

11 181+05.00 181+35.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Rotting of end Post Crossheads and wingwalls.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 120.0

12 183+70.00 183+90.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- No noticeable structural deterioration.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 140.0

Overall Section Rating

Union Hill Road Trailhead to Atlanta Highway

Crossing

13 207+50.00 208+50.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Deck boards are in ok condition.

- Some rotting of the 6"x6" "curbs".

- A lot of the Post Crossheads are excessively bowed.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 120.0 121.82

14 225+50.00 227+50.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Boardwalk is chipping and damaged from sun exposure.

- Mildew/fungi buildup on the tops of handrails.

- No noticeable structural damage.

5 122.0

Cattle Crossing

Boardwalk

(Not on Plans)

Approximately

229+60.00

Approximately

233+55.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

56.0

16 254+00.00 261+00.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Boards are rotting and chipping from sun exposure.

- There is excessive flooding on the sidewalk sections before and after this boardwalk section. 4

- No noticeable structural damage.

5 122.0

5 267+60.00 268+30.00 Prefabricated Steel Truss

- No noticeable structural deterioration.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 140.0

17 269+50.00 288+00.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Boardwalk is drying out and chipping from sun exposure.

- Railing is deteriorating and is loose. 3

- No noticeable excess mildew/fungi.

- The stringers are all bowed but not split.

- Handrail wobbly and warped. 4 110.0

6 296+75.00 297+55.00 Prefabricated Steel Truss

- No noticeable structural deterioration.

- No noticeable excess mildew/fungi.

- No noticeable structural damage except the handrail.

4.5 135.0

7 323+30.00 323+90.00 Prefabricated Steel Truss

- No noticeable structural deterioration except approach handrail.

- Sections of handrail are loose and

"burning".

4.5

- No noticeable excess mildew/fungi.

- No noticeable structural damage except the handrail.

4.5 130.0

18 325+75.00 338+50.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- No noticeable structural deterioration.

- This section was hard to see the Post

Crossheads and stringers due to the water/swamp. 5

- No noticeable excess mildew/fungi.

- No noticeable structural damage except the handrail which was loose and out of line.

4.5 135.0

19 344+80.00 353+60.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- No noticeable structural deterioration except handrail.

- Sections of handrail are loose. 4.5

- No noticeable excess mildew/fungi.

- No noticeable structural damage except the handrail.

4.5 130.0

8 353+60.00 354+20.00 Prefabricated Steel Truss

- No noticeable structural deterioration.

- No noticeable excess mildew/fungi.

- No noticeable structural damage.

5 140.0

20 354+20.00 356+00.00

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- No noticeable structural deterioration.

- Minor mold buildup on railings and boardwalk.

4.25

- No noticeable structural damage.

5 134.0

Overall Section Rating

Atlanta Highway Crossing to Bethelview Road

Trailhead

Boardwalk Closest to Bethelview Rd

Trailhead

(Not on Plans)

Stringer: 2" x 6"

Stringer Spacing = 2'-0" O.C.

Post Crosshead = 2" x 8"

- Wingwalls are rotting.

- Handrail/railing is rotting and deformed

6"-7" out of line.

- No noticeable excess mildew/fungi.

- No noticeable structural damage except the handrail.

4.5 125.0 123.25

Bethelview Road Trailhead

Atlanta Highway Crossing (Fowler Park)

Approximately 92'-0" Long

Approximately 615'-0" Long

Big Creek Greenway Structural Inspection McFarland Parkway Trailhead to Bethelview Road Trailhead

- Boardwalk is excessively chipping and rotting due to direct sunlight.

- Multiple broken and excessively bowing Post Crossheads.

- This section is only there to allow access between two properties. One of the properties has sold so this section is no longer necessary and can be replaced with concrete.

Page 4 of 5 8/23/2019

Boardwalk Bridge Start End Erosion (6) Rating Siltation (4) Rating Slab Settlement (3) Rating Boardwalk Score

1 14+35.00 15+80.00

- Minor erosion around the wingwalls, footings are exposed.

- No noticeable siltation

- No noticeable slab settlement, but with the footings being eroded in certain areas, settlement may begin.

4.5 51.5

2 19+30.00 20+40.00

- Erosion around and through boardwalk wingwalls.

4.5

- No noticeable siltation

- No noticeable slab settlement.

5 62.0

(Need to Re-Visit and Study Further)

22+50.00 43+45.00

- Erosion around and through the wingwalls.

- There is erosion around some of the footing supports.

- Minor siltation buildup.

- No noticeable slab settlement, but with the footings being eroded in certain areas, settlement may begin.

4.5 53.5

4 46+65.00 51+30.00

- No noticeable erosion.

- Minor siltation buildup to joist boards.

In time, silt may buildup to deck.

- No noticeable slab settlement.

5 61.0

5 54+90.00 72+85.00

- Small bridge over creek within boardwalk has major erosion around the footings. Almost the entire footing is exposed.

- Some of the boardwalk footings are exposed as well.

- Minor silt buildup to the boardwalk deck in one small area. (15-20 foot section).

- No noticeable slab settlement, but with the footings being eroded in certain areas, settlement may begin.

4.5 47.5

1 74+56.00 75+36.00

- No noticeable erosion.

- No noticeable siltation

- No noticeable slab settlement.

5 65.0

Overall Section Rating

(Out of 5)

McFarland Parkway

Trailhead to Union Hill

Road Trailhead

6 84+90.00 121+85.00

- Wingwall footings are exposed.

- Siltation buildup to joists in sections, this likely expedites the rotting of the wood.

- No noticeable slab settlement.

5 47.0 55.36

2 131+05.00 131+85.00

- Erosion around and through boardwalk wingwalls.

- No noticeable siltation

- No noticeable slab settlement.

5 59.0

7 131+85.00 133+04.00

- Erosion around and through boardwalk wingwalls.

- No noticeable siltation

- No noticeable slab settlement.

5 59.0

3 133+04.00 133+84.00

- No noticeable erosion.

- No noticeable siltation

- No noticeable slab settlement.

5 65.0

8 133+84.00 165+90.00

- No noticeable erosion.

- No noticeable siltation

- No noticeable slab settlement.

5 65.0

4 165+90.00 166+70.00

- No noticeable erosion.

- No noticeable siltation

- No noticeable slab settlement.

5 65.0

9 166+70.00 175+20.00

- Little bit of erosion around footings.

- Erosion around and through boardwalk wingwalls.

- Sidewalk on 175-20.00 end of boardwalk has major erosion on the edge of sidewalk. Undercuts sidewalk by a couple of inches.

- No noticeable siltation

- No noticeable slab settlement, but with the footings and edge of sidewalk being eroded in certain areas, settlement may begin.

4 50.0

10 178+55.00 178+70.00

- Minor erosion around the wingwalls.

- No noticeable siltation

- No noticeable slab settlement.

5 59.0

Big Creek Greenway Structural Inspection McFarland Parkway Trailhead to Bethelview Road Trailhead

McFarland Parkway Trailhead

Union Hill Road Trailhead

Page 5 of 5 8/23/2019

Boardwalk Bridge…