1305M326Q0067_SOW_A2_2025_Manchester_Pier_Load_Rating_Analysis_Report.pdf

Manchester Pier

Load Rating Report Manchester, WA

Submitted To:

Client:

GoldenWolf, LLC 9100 Conroy Windermere Road, Suite 200 Windermere, FL 34786

Owner:

National Oceanic and Atmospheric Administration 7600 Sand Point Way NE Seattle, WA 98115

William J. Lynes, PE Senior Structural Engineer Professional Engineer: Pennsylvania – No. PE082939

Load Rating Analysis Report

GOLDW24001

January 10, 2025

121 Continental Dr, Ste. 207 T: 302-655-4451 www.pennoni.com Newark, DE 19713 i

January 10, 2025

GOLDW24001

GoldenWolf, LLC Attn: Chris Flowers, Director of Asset Management 9100 Conroy Windermere Road Suite 200 Windermere, FL 34789

RE: FACILITY CONDITION ASSESSMENT AND STRUCTURAL ASSESSMENT

FOR THE NOAA – MULTIPLE SITES, FY24

TASK 4 – MANCHESTER, WA PIER INSPECTION

PHASE 2 – LOAD RATING ANALYSIS

Dear Mr. Flowers:

We are pleased to submit this Load Rating Analysis Report for the Manchester Pier located in Manchester, WA. Work was initiated in general accordance with the Scope of Services presented in our proposal dated June 26, 2024, and your subsequent authorization to proceed.

We trust that the information presented in this report is what you require at this time, and we thank you for the opportunity to assist you with this project. If you have any questions, or if you need any further assistance with this project, please contact this office at your earliest convenience.

Respectfully, PENNONI ASSOCIATES INC.

Katherine Kelly, ADCI, PE William Lynes, PE Senior Engineer / Underwater Inspector Senior Structural Engineer

2025-01-10

GoldenWolf, LLC / NOAA GOLDW24001 i

TABLE OF CONTENTS

Introduction Execut ive Summary Locat ion Map Site History , Descript ion, and Or ientat ion Purpose and Scope of Load Rat ing Analysis Design Standards and Technical References

Limitations and Disclaimers Scope of Analysis Assumed Mater ial Propert ies Condit ion Assessment Load Path Assumptions L ive Load and Vehicle Assumptions L imitat ions on Load Rat ing Increase Short -Term and Long-Term Recommendat ions Environmental and External Factors Professional Responsibi l i ty Intended Use of the Report Future Inspect ions and Evaluat ions General Disclaimer

Structural Systems Framing Plan and Site Layout Timber Decking Connect ions Mater ials of Construct ion and Assumed Propert ies

Structural Analysis Loads

Permanent (Dead) Loads Live Loads Environmental Loads

Load Cases and Combinat ions Considered Model ing and Analysis Methods

Geometric Accuracy Member Response Accuracy Unbraced Length of Piles

Sect ion Propert ies and Deter iorat ion Exclusion of Battered Pi les and Cross Bracing Ineffect ive/Nonbear ing Pi les

Interior Pile Ineffectiveness in 4-Pile Systems (Section 1) Interior Pile Ineffectiveness in 7-Pile Systems (Section 2) Summary of Findings

Load Rating Results Load Rat ing Summary

Stringers ii

Pile Caps with All Piles Effective Pile Caps with Ineffective Interior Pile Piles…

Discussion and Implicat ions Summary Discussion

Recommendations Immediate Act ions Short -Term Act ions Long-Term Act ions Load Restr ict ions/Suggested Operat ional Changes Maintenance Recommendat ions

Conclusion Appendix A: Sketches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A Appendix B: Load Rat ing Analysis Calculat ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B Appendix C: Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C Appendix D: STAAD Output Fi les . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D

Introduction Executive Summary The Manchester Pier, located in Manchester, Washington, at approximately 47°33'25"N, 122°32'37"W, serves as a waterfront access structure. Originally constructed circa 1930, the pier has significantly exceeded its intended service life. Despite its age, it remains in active use, albeit under reduced loading conditions compared to its original design parameters.

This load rating analysis evaluates the pier's structural capacity under current and anticipated conditions, incorporating observed material deterioration and environmental exposure. The analysis includes a detailed assessment of critical structural elements, an evaluation of the lateral load capacity of the timber piles in their existing state, and load rating factors for various components.

Key findings indicate that, while the pier exhibits signs of aging and wear, targeted repairs and routine maintenance can extend its service life and ensure safe operation while long-term usage is evaluated. Recommendations include specific repair measures, load restrictions, and a maintenance plan to address observed deficiencies and prevent further deterioration.

This report serves to guide decision-making regarding the pier's future use and management, ensuring its continued functionality as a key asset in the Manchester waterfront area.

Location Map

Figure 1 - Location Map

Site History, Description, and Orientation For a thorough recount of the site history, description, and orientation, refer to the Manchester Pier Inspection Report dated 11/27/2024, prepared by Pennoni.

Purpose and Scope of Load Rating Analysis The primary objective of this load rating analysis is to evaluate the structural capacity of the Manchester Pier under both standard design loads and specific operational requirements provided by the owner, NOAA. The pier is currently posted for a maximum load of 8,000 lbs (4 tons), which restricts its use for heavier vehicles and equipment.

NOAA intends to use the pier for the transport of fish/water tanks and equipment utilizing trailers and light-duty pickup trucks. To facilitate this, the load rating analysis focuses on:

• Assessing the pier's capacity to support the code-specified pedestrian loads and H10 design vehicle, as outlined in applicable standards.

Structure Location

• Evaluating the structural adequacy of the pier for the owner-supplied vehicle, which represents typical operational loads for NOAA's activities.

This analysis encompasses:

• A review of the pier's condition, materials, and structural layout.

• Consideration of live load and environmental load effects, in conjunction with observed material degradation.

• Development of load rating factors to determine whether the pier can safely support the specified loads under various scenarios.

The results of this analysis will provide NOAA with actionable insights to inform operational decisions, identify necessary repairs, and ensure the safe and continued use of the pier for its intended functions.

Design Standards and Technical References This load rating analysis is in accordance with the Load and Resistance Factor Rating (LRFR) methodology, and references the following standards, guidelines, and supporting documents:

• American Association of State Highway and Transportation Officials (AASHTO). AASHTO LRFD Bridge Design Specifications. 9th Edition, Washington, D.C., 2020.

• American Association of State Highway and Transportation Officials (AASHTO). AASHTO Manual for Bridge Evaluation. 3rd Edition, Washington, D.C., 2018.

• American Association of State Highway and Transportation Officials (AASHTO). Guide Specifications for the Design of Pedestrian Bridges. Current Edition, Washington, D.C.

• American Society of Civil Engineers (ASCE). ASCE 7-22: Minimum Design Loads and Associated Criteria for Buildings and Other Structures. Reston, VA, 2022.

• Ford (Ford). 2025 Ford Super Duty F-250 XLT Truck Model Details & Specs.

https://www.ford.com/trucks/super-duty/models/f250-xlt/. Accessed 2024-12-19.

• Pennoni. Manchester Pier Inspection Report. 2024-11-27.

• Previous load rating analysis for the Manchester Pier, provided by the pier owner (NOAA).

These resources provide the basis for determining applicable design loads, analyzing the pier’s structural behavior, and evaluating its capacity under operational conditions.

Limitations and Disclaimers Scope of Analysis This load rating analysis was performed based on the condition assessment and inspection data provided at the time of evaluation. The findings and recommendations are limited to the specific structural components and load cases addressed in this report. No warranty, expressed or implied, is made regarding the condition of the structure outside the scope of this evaluation.

Assumed Material Properties The material properties of the existing timber components were assumed due to the lack of definitive documentation.

These assumed values were derived from industry standards and conservative engineering judgment and may not reflect the actual material properties.

Condition Assessment This analysis relies on inspection data gathered per best practices, which inherently carries limitations. Internal conditions, hidden defects, or deterioration not visible or accessible during the inspection may impact the actual performance of the structure and were not accounted for in this analysis.

Load Path Assumptions The load paths for deteriorated and ineffective piles cannot be precisely determined. Assumptions regarding load distribution and behavior were made to facilitate the analysis. Actual load transfer mechanisms may vary, potentially affecting the conclusions of this report.

Live Load and Vehicle Assumptions The live load rating assumes the specific live load effects outlined in this report, including pedestrian loading and the owner-specified vehicle. The analysis does not account for abnormal or unexpected loading conditions, dynamic effects, or overloading beyond the parameters defined herein.

Limitations on Load Rating Increase The pier is currently posted for an 8,000 lb (4 ton) load limit. Engineering judgment and observed conditions do not support an increase to this posting without significant repairs and a subsequent evaluation. Any deviation from the recommendations or changes in the structure's use in the future should be re-assessed by a professional engineer.

Short-Term and Long-Term Recommendations Short-term repairs to address deteriorated piles or other deficiencies must be completed in accordance with the recommendations herein and industry standards. Long-term replacement of structural components should follow a comprehensive evaluation and design process. The performance of the structure after repairs or modifications must be verified by additional structural analysis.

Environmental and External Factors This analysis does not account for unanticipated environmental conditions, such as extreme weather, flooding, or seismic events, that may affect the performance or safety of the structure.

Professional Responsibility The findings, conclusions, and recommendations presented in this report are based on professional engineering judgment and generally accepted practices at the time of analysis. The authors of this report accept no liability for conditions, defects, or damages arising from improper maintenance, unanticipated events, or deviations from the recommended actions.

Intended Use of the Report This report is intended solely for use by the pier owner and their designated representatives for decision-making regarding the structure's operational use and maintenance. It is not intended for distribution or reliance by third parties without written consent from the authors.

Future Inspections and Evaluations Regular inspections and evaluations should be conducted to monitor the condition of the structure and verify compliance with load rating recommendations. Changes in the condition or usage of the structure may require a new load rating analysis or updates to this analysis.

General Disclaimer The recommendations provided in this report are made with the intention of supporting the safe and efficient use of the structure based on the data and assumptions available. The authors accept no responsibility for misuse or misinterpretation of the findings and recommendations contained herein.

Structural Systems Please refer to the accompanying Manchester Pier Inspection Report for a thorough description of all members, including their sizes, locations, and defects.

Framing Plan and Site Layout Geospatial point cloud data was available publicly through the Washington State Department of Natural Resources LIDAR portal (https://lidarportal.dnr.wa.gov/#47.40950:-122.03613:7). Point cloud data was used to accurately model the structure in its correct horizontal and vertical coordinates. Locating the structure horizontally is inconsequential to the analysis results; however, by utilizing the LIDAR data, geospatially correct terrain and elevations may be determined for the application of wind and environmental loads.

Span data was taken from field measurements. A notional model of seven (7), simple spans is constructed to capture two spans of narrow deck, three spans of transition, and two spans of the wide deck segments. Wind load is not applied below the water line (Elevation = 0). The notional model adequately envelops the constant and variable deck width sections, capturing all desired load effects.

Timber Decking Timber decking is easily replaced, and defects are easy to visually identify. Likewise, decking is reasonably simple and inexpensive to replace on a per-element basis; therefore, timber decking is considered a consumable element and is not explicitly rated for safe load carrying capacity. Refer to the Manchester Pier Inspection Report for timber deck recommentations.

Additionally, this load rating analysis does not assume timber decking is adequately nailed or otherwise connected effectively to the stringers to leverage increased load carrying capacity of composite section action. Therefore, the timber decking is not considered a structural element in this analysis.

Figure 2 - Plan view of structural analysis model highlighting enclosed deck

Connections All connections are assumed to be simple, meaning the connections are not to transfer moments between members.

There are no moment splices nor fully restrained boundary conditions present on the structure. The timber pile caps are continuous over the piles. Connections are assumed to adequately transfer the intended forces between members and are explicitly not evaluated for safe load capacity.

Materials of Construction and Assumed Properties The grade of the existing timber used in the Manchester Pier is unknown, and no detailed information is available to make a precise determination of its properties. Due to this uncertainty, certain assumptions were made regarding the material properties of the timber elements. These assumed values are based on typical values for similar timber grades and were selected to ensure a conservative evaluation of the pier’s capacity. The table below provides the nominal reference design values for the assumed timber grade, which were used in the structural analysis to represent the behavior of the material under load:

Member

Young's Modulus

Bending Stress

Shear Stress

Compressive Stress

E (ksi)

Fbo

(ksi)

Fvo

(ksi)

Fco

(ksi)

Stringers 1500.00 1.60 0.17 --

Pile Caps 1500.00 1.60 0.17 --

Piles 1000.00 2.45 0.11 1.25

Table 1 - Assumed reference design values

Generally, these values were selected qualitatively and based on engineering judgment. Table 8.4.1.1.4-1 in AASHTO provides tabulated reference design values for visually graded lumber. The values listed above are generally representative of Douglas Fir-Larch timber, a grade commonly used in construction regionally, at Select Structural commercial grade.

Structural Analysis The structural analysis of the Manchester Pier was conducted using linear static analyses with finite element software to calculate the internal forces, moments, and displacements under various load conditions. Section properties and deterioration effects were determined using hand calculations and relevant code equations to estimate the impact of material degradation on load-carrying capacity.

Loads Permanent (Dead) Loads The unit weight (density) applied to the rated elements – the stringers, pile caps, and piles – is assumed conservatively as 60 pounds per cubic foot (pcf). As is common practice in the analysis of as-built members with varying and non-uniform properties, a surcharge of 10% of the calculated self-weight is added to account for miscellaneous hardware and non-structural attachments.

The timber curb is assumed conservatively as 75 pounds per lineal foot (plf). This is applied as a line load along the exterior edges of the deck. The weight of the curb is distributed according to structural stiffness of the connected elements in the analysis model.

A uniform pressure of 20 pounds per square foot (psf) is applied to the entire deck surface. This load accounts for the weight of the timber decking (not explicitly rated or modeled) and miscellaneous permanent loads applied uniformly to the deck.

Transient (Live) Loads The structural analysis for the Manchester Pier considered three primary live load cases to evaluate its capacity under various usage scenarios. The live vehicles are assumed to have 6'-0" gage distance between wheels. Per AASHTO specifications, timber is inherently self-dampening and is not subject to the dynamic live load allowance typically applied to concrete and steel superstructures. The analysis assumed four (4), 12'-0" wide lanes across the structure at its widest, with the following loading scenarios applied:

1. Uniform Pedestrian Load o The entire structure was loaded with a uniform live load pressure of 100 psf, representing pedestrian traffic.

2. H10 Vehicle Load with Uniform Pedestrian Load o The H10 vehicle was positioned in a single lane, while the remaining three lanes were simultaneously loaded with the 100 psf pedestrian load. The total weight of the H10 vehicle is 20,000 lbs (10.0 tons).

Figure 3 - H10 Loading (Source: AASHTO)

3. Owner-Specified Vehicle (OSV) Load with Uniform Pedestrian Load o The OSV was placed in a single lane, with the other three lanes simultaneously loaded with the 100 psf pedestrian load. The total computed weight of this notional vehicle is 18,140 lbs (9.1 tons).

Figure 4 - OSV Loading

Each case was evaluated to determine critical load effects on the pier's structural elements. These scenarios address both uniform and concentrated live loads to reflect the expected operational and design conditions of the pier.

Please note that the simple span lengths between piers is 10'-0" (120"), which is less than the minimum axle spacing of either the H10 or OSV (159.7"); therefore, each span is only ever loaded with a single vehicle axle at a time.

Environmental Loads Environmental loads such as wind and seismic movement are not generally considered in live load analyses; however, the piles are the primary sources of lateral structural stability with respect to wind resistance. Wind loads are considered in the analysis of the piles, which will undergo simultaneous axial loading and bending.

Refer to Appendix B:

Load Rating Analysis Calculations for a complete list and detailed explanation of assumptions and parameters used in the determination of the wind pressures used in analysis. For the load case of Pedestrian with Wind presented in the Table below, an ultimate wind speed of

Load Cases and Combinations Considered The principle of superposition is used to combine the service load effects from the combined dead load, uniform live load, H10 LL, OSV LL, and wind load cases.

The following table summarizes the loads, load factors, and load combinations:

Description Load Case γDC γLL

(H10) γLL

(OSV)

γLL

(uniform) γWS

H10 Inventory Rating Strength I 1.25 1.75 -- 1.75 --

H10 Operating Rating Strength I 1.25 1.35 -- 1.35 --

OSV Legal Rating Strength I 1.25 -- 1.30 1.30 --

Pedestrian Operating Rating

Strength I 1.25 -- -- 1.35 --

Pedestrian with Wind Strength V 1.25 -- -- 1.35 0.64

Table 2 - Load Cases and Combinations

Modeling and Analysis Methods The notional, 7-span model was constructed and analyzed with the structural analysis software STAAD.pro 2023 Edition. STAAD.pro is a structural analysis software that uses finite element analysis (FEA) to model and evaluate the behavior of structures under various load conditions. For the Manchester Pier, STAAD.pro was used to create a detailed model incorporating timber beams, piles, and pile caps, while applying dead, live, and environmental loads as specified by AASHTO LRFD codes. The software performs static analysis, calculating internal forces, moments, and displacements, and evaluates both strength and serviceability criteria. STAAD.pro also allows for the superposition of load cases and combinations to determine load ratings, ensuring the pier’s capacity meets safety and operational requirements.

Geometric Accuracy To accurately represent the geometric offsets between the centroids of structural members, rigid link elements are used in the modeling process. These link elements are massless, have relatively infinite strength and stiffness, and are employed to connect different points in the model, allowing for the transfer of forces and moments while maintaining the spatial separation between the centroids of connected members. This technique ensures that the structural behavior is accurately captured, particularly when members with different axial and bending properties are connected at an offset. Rigid links prevent unintended deformations at the connection points and help simulate realistic load distribution across the structure.

Member Response Accuracy Releasing beam ends for moment in structural modeling is a technique used to simulate simple supports or connections where moment transfer is not expected. In this approach, the beam’s end nodes are freed from carrying bending moments, effectively allowing the beam to behave as if it is connected to a hinge or pinned support. This is commonly applied in cases where the actual physical connection does not resist moments, such as in simple span bridges or structures with moment-resisting connections. By releasing the moment at the beam ends, the model more accurately reflects the real-world behavior of the structure and simplifies the analysis of internal forces and deflections.

Unbraced Length of Piles The inspection revealed varying depths to the channel bottom. For lateral force analysis, the depth to fixity of the piles was conservatively assumed to be 35 feet below an assumed channel bottom. Additionally, a maximum unsupported height of 15 feet above the assumed channel bottom was considered, accounting for worst-case scenarios of reduced lateral bracing. This results in a total unbraced column length of 50 feet, which was used in the structural analysis to assess pile stability.

Piles must resist a combination of axial compression from vertical loads and bending moments from lateral forces, such as wind, wave action, or impact loads. The interaction between these forces is critical because excessive bending can reduce a pile's axial load-carrying capacity, while high axial loads can increase the risk of buckling under lateral forces. The unbraced length directly influences the pile's susceptibility to these effects, as longer unbraced columns are more prone to instability. This highlights the importance of accurately determining pile fixity and unbraced lengths in assessing the structure's overall safety and stability.

Section Properties and Deterioration The structural elements of the Manchester Pier were modeled using their nominal dimensions, as the stringers and pile caps are in generally good condition and exhibit minimal signs of deterioration. These elements were analyzed in their full, undeteriorated state, with their assumed values for modulus of elasticity used to represent feasible flow of forces through elements due to relative stiffnesses.

In contrast, the condition of the piles presents significant challenges for modeling. Many piles exhibit varying degrees of deterioration, with some showing no bearing capacity with the pile caps, while others have experienced up to 100% section loss in certain segments. Additionally, most piles exhibit internal rot to some degree. Given the variability and complexity of these conditions, it was not feasible to accurately model the full extent of the deterioration in the analysis.

Instead, the analysis model utilized the full, undeteriorated section properties of the piles, along with assumed values for modulus of elasticity, to approximate realistic load distribution through the deteriorated sections. For the deterioration effects, hand calculations were performed using relevant code equations to estimate the reduction in load-carrying capacity and stiffness, providing a conservative estimate of the piles' behavior under load.

Exclusion of Battered Piles and Cross Bracing The battered piles and cross bracing elements were excluded from the lateral force analysis due to the inherent uncertainties associated with their load-transfer behavior in the current deteriorated state. The piles, designed primarily to resist lateral forces through axial compression, rely on robust connections and material integrity for effective load distribution. However, the inspection findings indicate significant deterioration in multiple elements, including loss of section and unknown conditions at the connections to the pile caps.

Given these conditions, the load-carrying capacity and effective stiffness of the battered piles are highly uncertain, making it impractical to reliably incorporate them into the analysis model. Furthermore, the lateral force analysis conservatively assumes that the vertical piles resist lateral forces through flexural and axial mechanisms, providing a more straightforward and reliable assessment of the pier's lateral stability.

This approach aligns with conservative engineering practices, ensuring that the analysis is based on known and predictable structural behavior rather than additional speculative assumptions about compromised elements.

Additional inspection or testing of the battered piles could provide data to refine this analysis in the future, but for the purposes of this evaluation, their contribution was conservatively neglected.

Ineffective/Nonbearing Piles To assess the structural effects of ineffective or nonbearing piles on the Manchester Pier, a parametric analysis was conducted by selectively removing individual interior piles from the model. The study evaluated the redistribution of forces among the remaining piles as well as the resulting internal shears and moments within the pile caps. Two representative configurations were considered: a 4-Pile system and a 7-pile system.

Figure 5 - Typical ineffective bearing contact between pile and cap

Interior Pile Ineffectiveness in 4-Pile Systems (Section 1) In the 4-Pile system (designated Section 1 in the Table below), one interior pile was assumed to be completely ineffective, representing scenarios such as complete section loss or the loss of bearing contact with the pile cap. The analysis revealed significant changes in load distribution among the remaining piles, with adjacent piles carrying additional axial load to compensate for the ineffective pile. This redistribution was accompanied by equally proportional increases in internal shear and moment demands on the pile caps. The pile caps experienced localized stress concentrations in areas near the ineffective pile, highlighting their critical role in accommodating altered load paths and maintaining structural stability.

Interior Pile Ineffectiveness in 7-Pile Systems (Section 2) A similar analysis was performed on a 7-pile system (designated Section 2 in the Table below), where the loss of one interior pile resulted in a more distributed but still measurable redistribution of loads. The larger number of piles provided additional redundancy, limiting the increased load on adjacent piles. Despite this, the pile caps exhibited comparable trends in shear and moment redistribution, with stress concentrations occurring around the ineffective pile location. The results emphasize the pile caps' role as integral components of the structural system, managing redistributed forces when piles become ineffective.

Summary of Findings The analysis demonstrated that the loss of an interior pile—whether in a 4-Pile or 7-pile system—has a significant impact on both the piles and the pile caps. The pile caps must resist the increased shear and moment demands resulting from altered load paths, while the remaining piles carry greater axial loads. These findings reinforce the need for immediate repair measures to restore effective load paths and reduce overstress conditions in both the piles and pile caps.

The tables below summarize the results of increases in shear and moment demands to the pile caps, and axial force and moments in the piles, resulting from the ineffective piles in both systems:

Member Load Case Load Type

Unit Baseline

Load Section 1

Load Section 1

(Δ%) Section 2

Load Section 2

(Δ%)

Piles

H10 Inventory Axial kip 38.48 40.13 4.3% 39.35 2.3%

Moment kip*ft 0.03 0.03 0.0% 0.03 0.0%

H10 Operating Axial kip 31.60 33.13 4.8% 32.47 2.8%

Moment kip*ft 0.02 0.02 0.0% 0.02 0.0%

100 psf Operating

Axial kip 9.73 11.66 19.9% 11.28 15.9%

Moment kip*ft 0.00 0.00 0.0% 0.00 0.0%

100 psf Operating w/ Wind

Axial kip 10.01 12.08 20.7% 11.77 17.6%

Moment kip*ft 55.99 56.34 0.6% 56.34 0.6%

OSV Legal Axial kip 23.85 31.47 32.0% 27.71 16.2%

Moment kip*ft 0.02 0.02 0.0% 0.02 0.0%

Table 3 - Increased Load Demands on Piles Due to Non-Bearing Piles

Member Load Case Load Type

Unit Baseline

Load Section 1

Load Section 1

(Δ%) Section 2

Load Section 2

(Δ%)

Pile Caps

H10 Inventory Shear kip 18.70 22.38 19.7% 21.15 13.1%

Moment kip*ft 64.50 64.79 0.4% 64.59 0.1%

H10 Operating Shear kip 15.34 18.18 18.5% 17.23 12.3%

Moment kip*ft 51.94 51.94 0.0% 51.94 0.0%

100 psf Operating

Shear kip 4.81 5.22 8.4% 5.22 8.4%

Moment kip*ft 10.76 12.38 15.1% 12.37 15.0%

OSV Legal Shear kip 13.23 16.74 26.5% 14.27 7.9%

Moment kip*ft 28.30 42.04 48.6% 34.16 20.7%

Table 4 - Increased Load Demands on Pile Caps Due to Non-Bearing Piles

Load Rating Results A load rating is a measure of a structure’s capacity to safely carry loads, such as vehicles or pedestrian traffic, under specific conditions. The process involves determining a load rating factor, which is based on the desired live load effect, such as the expected vehicle load or pedestrian traffic. This rating factor reflects the structure's ability to support the live load while accounting for factors like material strength and condition. Once the rating factor is determined, it is multiplied by the live load value to calculate the safe load capacity of the structure, ensuring that it can safely support the expected loads without failure. This expression is represented mathematically as follows:

Where C represents the factored resistance (capacity), γDCDC represents the factored dead load effect, and γLLLL represents the factored life load effect.

Load Rating Summary Stringers

Load Case

GVW

(tons)

RF Rating (tons) Effect

H10 Inventory 10.00 0.62 6.18 Moment

H10 Operating 10.00 0.80 8.01 Moment

OSV Legal 9.10 0.84 7.67 Moment

100 psf Operating

100.00 1.00 100.00 Shear

Table 5 - Stringers Rating Summary

Pile Caps with All Piles Effective

Load Case

GVW

(tons)

RF Rating (tons) Effect

H10 Inventory 10.00 1.32 13.17 Moment

H10 Operating 10.00 1.71 17.10 Moment

OSV Legal 9.10 3.11 28.30 Moment

100 psf Operating

100.00 1.00 100.00 Shear

Table 6 - Pile Caps (All Piles Effective) Rating Summary

Pile Caps with Ineffective Interior Pile

Load Case

GVW

(tons)

RF Rating (tons) Effect

H10 Inventory 10.00 1.32 13.17 Moment

H10 Operating 10.00 1.71 17.10 Moment

OSV Legal 9.10 2.23 20.29 Moment

100 psf Operating

100.00 1.00 100.00 Shear

Table 7 - Pile Caps (1 Pile Ineffective) Rating Summary

Piles

Load Case

GVW

(tons)

RF Rating (tons) Effect

H10 Inventory 10.00 0.34 3.40 Axial

H10 Operating 10.00 0.44 4.40 Axial

OSV Legal 9.10 0.66 6.01 Axial

100 psf Operating

100.00 7.34 734.00 Axial

Table 8 - Piles Rating Summary (Overall governing rating and posting limit highlighted in yellow)

From the above results, the piles control the overall load carrying capacity of the structure as expected. As is common practice for highway bridges, the design vehicle (H10) operating rating is used to determine the governing safe load capacity of the structure.

Discussion and Implications Summary

• The existing weight limit of 8,000 lbs (4 tons) shall remain.

• The OSV has a safe load capacity of 12,000 lbs (6 tons). As this vehicle is more precisely known, a lower factor of safety is applied to it and should not, therefore, but used in normal posting decisions.

• After positive connections have been made (shimming), the OSV may continue to operate with a maximum gross vehicular weight of 12,000 lbs (6 tons) assuming the same axle configuration shown in this report.

Discussion Rating factors below 1.0 for the H10 vehicle load cases are expected. The H10 is a notional code design vehicle that was established after the construction of the pier. This rating justifies the existing posting of 4 tons and the decision for this limit to remain in effect.

The pile caps that considered all piles effective in bearing achieved rating factors exceeding 1.0 for all load effects considered in the analysis, indicating their capacity to safely convey the intended loads. This outcome is consistent with expectations, given the relatively recent installation of these elements and their observed structural integrity during the inspection. The lack of significant deterioration or damage in the pile caps reinforces their role as reliable components in the overall load path of the pier structure.

Under the one-pile-ineffective pile cap model, the analysis revealed only a slight decrease in the OSV rating, dropping from 28 tons to 20 tons, which represents a 28% reduction. All calculated load rating factors remained above 1.0, indicating that the structure still meets the safety requirements for the intended loads. However, it is still imperative that positive connections (shims) are installed immediately to ensure structural stability.

The rating results for the piles exhibited significant variability, reflecting the inherent uncertainties in their condition.

Conservative assumptions were applied to ensure safety, including a reduced Young’s modulus of 1,000 ksi to account for potential deterioration and material variability. Additionally, an unbraced column length of 50 feet was used in the analysis, representing an extreme case that is highly likely to encompass the actual conditions of all piles. These conservative parameters provide a cautious basis for assessing the load-carrying capacity of the piles under the observed conditions.

The OSV was rated at 12,000 lbs (6 tons) axial capacity, which is greater than the current posted load limit of 8,000 lbs (4 tons). As previously noted, the Young’s modulus for the piles was conservatively assumed to be 1,000 ksi to reflect potential internal deterioration. Given the unknown load paths due to internal deterioration and the evident satisfactory performance of the pier under the specified loads provided by the owner, engineering judgment supports the conclusion that the OSV continued operation is acceptable with immediate implementation of restoring positive connections between all piles and pile caps.

Recommendations This section builds on the thorough recommendations provided in the inspection report by adding commentary specific to the pier's structural load-carrying capacity. The inspection report's recommendations remain valid, and this analysis highlights critical action items to ensure the pier’s continued safe use.

Immediate Actions The most immediate and critical action is to replace the deteriorated piles in the end bent as recommended in the inspection report. Until these replacements are completed, the two end spans must be restricted from heavy vehicular traffic to prevent overstressing the remaining structural elements.

Another urgent priority is to provide positive connections between the pile caps and all non-load-bearing piles. These connections can be achieved by shimming, ideally using plastic shims to minimize future maintenance. Plastic shims are preferred over pressure-treated lumber as they resist degradation and rot, reducing the need for frequent re-shimming.

Short-Term Actions Regular monitoring (inspections) and a scheduled routine maintenance plan for ongoing use of the structure should be implemented.

Long-Term Actions

Looking forward, it is essential to develop a comprehensive pile replacement plan to address the general deterioration and internal rot affecting the pier's load-carrying capacity. This plan should prioritize piles with the most severe deterioration and aim to restore the structural integrity of the entire pier over time.

Load Restrictions/Suggested Operational Changes The pier is currently posted for an 8,000 lb (4 ton) load limit, and this restriction cannot be increased based on current engineering judgment and the observed conditions of the structure. Immediate action to provide positive connections between the pile caps and nonbearing piles—such as shimming with plastic or pressure-treated lumber—is critical. Once these connections are in place, the structure may safely accommodate the owner-specified vehicle (OSV) operating on the pier, along with simultaneous pedestrian loading elsewhere on the structure.

Maintenance Recommendations Short-term repairs to strengthen critically deteriorated piles could allow for a potential increase in the load limit, but this would require a follow-up structural evaluation to confirm feasibility. However, given the ongoing deterioration and the age of the pier, a comprehensive long-term replacement plan should be developed and executed as soon as practical to ensure the structure's safety and continued functionality.

These measures, combined with routine inspections and proactive maintenance, will help extend the service life of the Manchester Pier while ensuring its safe operation for NOAA's intended use.

Conclusion Despite its age and signs of deterioration, the load rating analysis of the Manchester Pier indicates that the structure can continue to safely support its current loads with the immediate implementation of necessary repairs and maintenance. The analysis was conducted with conservative assumptions regarding material properties and deterioration, as the material grades of the pier’s timber elements are unknown. The pier is currently posted for 8,000 lbs (4 tons), and sound engineering judgment does not justify raising this posting due to the uncertainty surrounding the deteriorated piles, whose load paths cannot be precisely known.

Immediate action is required to provide positive connections for the non-bearing piles, which will help stabilize the structure. Once these connections are made, the pier will be able to safely carry the owner-supplied vehicle (OSV) and pedestrians. However, the pier will not be able to support the H10 vehicle under current conditions. Recommendations for repair, load restrictions, and maintenance are outlined to ensure the continued safe use of the pier for NOAA’s operational needs, and to extend the pier's service life with the implementation of routine inspections and targeted repairs.

APPENDIX

Appendix A:

Sketches

SH 2024-01-09

Appendix B:

Load Rating Analysis Calculations

Contents

1 Loads 1-2

1.1 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.2 ASCE-7 Online Hazard Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1.3 Owner-Specified Vehicle Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

2 Analysis Narrative and Summary 2-1

2.1 Capacity and Rating Factor Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.1.1 Stringers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2.1.2 Pile Caps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2.1.3 Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.2 Loads Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

2.3 Model Construction Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36

2.4 Output Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44

0-1

1 Loads

1-2

1.1 Calculations

1-3

JOB NO. GOLDW24001

SHEET DATE

PROJECT Manchester Pier Inspection Load Rating BY: WJL 2024-10-25

SUBJECT Loads and Load Combinations CHK'D xyz yyyy-mm-dd

Description The purpose of this workbook is to quantify the permanent and live loads applied to various members for determination of safe live load carrying capacity. The intent is to use the principles of superposition and influence diagrams to position the transient loads to produce the maximum member load effects.

Standards and References AASHTO. "LRFD Bridge Design Specifications." 9th Edition, 2020. LRFDBDS.

"LRFD Guide Specifications for the Design of Pedestrian Bridges." 2nd Edition, 2015. GSDPB.

"Manual for Bridge Evaluation." 3rd Edition, 2018. MBE.

ASCE. "ASCE Hazards Report." https://ascehazardtool.org. Accessed 2024-10-25. ASCE.

Ford. "2025 Ford Super Duty F-250 XLT Truck Model Details & Specs." https://www.ford.com/trucks/super-duty/ models/f250-xlt/. Accessed 2024-12-19. FORD.

Methodology and Assumptions

Structural analysis is in accordance with the Load and Resistance Factor Rating (LRFR) methodology.

Wind Loading

ASCE 7 Online Hazard Tool Used for Wind Speed Category II Building Assumed Height above water from water = < 33 ft To minimize the number of unique load cases generated in the analysis, wind speeds corresponding to the limit states will be applied to the model by scaling the ultimate wind speed pressure proportionally to the squares of wind speeds Wind Exposure Category C, AASHTO Sec. 3.8.1.1.4 Wind effects will be enveloped by a directional procedure, considering the governing load effects from wind angles of attach from the south, north, and northwest

Live Loading

Impact is not applied to the timber structure per LRFDBDS-9 § 3.6.2.3.

Load case 1, uniform loading: All spans are uniformly loaded with an appropriate live load pressure (STRENGTH 1) of , which envelopes the AASHTO pedestrian design load with surcharge to ≔pLL 100 psf account for equipment, loading, and other transient loads.

Load case 2, H-10 design vehicle: H-10 truck without impact positioned in one lane with simultaneous uniform live load pressure applied in remaining lanes (STRENGTH 2) Load case 3, Owner vehicle #1: Truck without impact positioned in one lane with simultaneous uniform live load pressure applied in remaining lanes (STRENGTH 2) Load case 4, Owner vehicle #2: Truck without impact positioned in one lane with simultaneous uniform live load pressure applied in remaining lanes (STRENGTH 2) Load case 5, uniform loading w/ 70mph wind: All spans are uniformly loaded with uniform live load pressure with simultaneous wind pressure at 70mph Longitudinal braking force is not considered due to the low travel speed. Notional longitudinal loads equal to 2% of permanent gravity loads will be considered in both lateral directions simultaneously to envelope stability considerations.

Loads 1-4

LM 2024-12-27

PROJECT Manchester Pier Inspection Load Rating BY: WJL 2024-10-25

SUBJECT Loads and Load Combinations CHK'D xyz yyyy-mm-dd

Loads

Dead Loads A factor of 1.10 will be applied to the automatic calculation of the member self-weights to conservatively account for growth, debris, and variability in material densities.

Assumed weight of bull railing, applied lineally along the exterior members

≔wrail 75 plf

Assumed density of all timber ≔ρ 60 pcf Assumed weight of decking and incidental permanent loads acting uniformly on stringers

≔pDL 20 psf

Wind Loading

Ultimate design wind speed ≔Vu 97 mph Ref: ASCE-7 Online Hazard Tool

Wind speed at Strength V ≔V5 80 mph

Wind speed at Service I ≔V1 70 mph

Wind pressure ≔p ⎛⎝ ,,,V Kz G CD ⎞⎠ ⋅⋅⋅⋅⋅⋅2.56 10-6 ⎛

V mph

Kz G CD ksf AASHTO Eq. 3.8.1.2.1-1

≔Kz 1.0 ≔G 1.0

≔CD 1.3

Strength III (ultimate) ≔pSTR3 =p ⎛⎝ ,,,Vu Kz G CD ⎞⎠ 31.313 psf

Strength V ≔pSTR5 =p ⎛⎝ ,,,V5 Kz G CD ⎞⎠ 21.299 psf

Service I ≔pSVC1 =p ⎛⎝ ,,,V1 Kz G CD ⎞⎠ 16.307 psf

Scaling factors for load application (for reference for STAAD input only)

Live Loads (Vehicles) 1-5

PROJECT Manchester Pier Inspection Load Rating BY: WJL 2024-10-25

SUBJECT Loads and Load Combinations CHK'D xyz yyyy-mm-dd

Live Loads (Vehicles) H10 -- Required for clear deck widths over 10ft per GSDPB-2 Table 3.2-1

Owner-specified vehicle -- Wylie 550 Gallon Express Water Wagon trailer. Assume this trailer is fully loaded with published GVW. Assume a Ford F-250 Super Duty Crew Cab model pickup truck.

Truck Axle spacing (wheelbase), Crew Cab ≔S1 =159.7 in 13.308 ft

Truck Gage (track) ≔G1 =69.5 in 5.792 ft Say ≔G1 6 ft

Truck Front axle

GAWR

≔P1 5600 lbf

Truck Rear axle GAWR ≔P2 6340 lbf

Trailer Axle spacing ≔S2 =162 in 13.5 ft

Trailer Gage (track) ≔G2 =70.5 in 5.875 ft Say ≔G2 6 ft

Trailer GVWR ≔P3 6200 lbf Total GVW

≔W_OSV1 ++P1 P2 P3 =W_OSV1 18140 lbf =W_OSV1 9.1 tonf

Load Combinations See Appendix for Tabulated Load Combinations. The load combinations are automatically generated based on user-defined load factors and combination parameters.

1-6

1.2 ASCE-7 Online Hazard Report

1-7

ASCE Hazards Report Address:

No Address at This Location

Standard: ASCE/SEI 7-22 Latitude: 47.573718

Risk Category: II Longitude: -122.544942

Soil Class: Default Elevation: 0 ft (NAVD 88)

Wind

Results:

Wind Speed 97 Vmph

10-year MRI 67 Vmph

25-year MRI 73 Vmph

50-year MRI 78 Vmph

100-year MRI 83 Vmph

300-year MRI 92 Vmph

700-year MRI 97 Vmph

1,700-year MRI 104 Vmph

3,000-year MRI 108 Vmph

10,000-year MRI 117 Vmph

100,000-year MRI 135 Vmph

1,000,000-year MRI 154 Vmph

Data Source: ASCE/SEI 7-22, Fig. 26.5-1B and Figs. CC.2-1–CC.2-4, and Section 26.5.2

Date Accessed: Fri Oct 25 2024

Page 1 of 3https://ascehazardtool.org/ Fri Oct 25 2024

REFERENCE FOR LOADS CALCULATIONS

1-8

1.3 Owner-Specified Vehicle Information

1-9

SUPER DUTY

2021 FORD

F-250 F-350 F-450

SUPER DUTY

2021 FORD

F-250 | F-350 | F-450

REFERENCE FOR LOADS CALCULATIONS

AVAILABLE TRIM PACKAGES

XL

Power Equipment Group: accessory delay for power features; trailer tow mirrors with 2-way fold, power/heated glass and heated manual spotter mirrors; Advanced Security Pack with inclination/ intrusion sensors; power door and tailgate locks; power windows with front one-touch-up/-down feature; upgraded door-trim panels, and Remote Keyless Entry System with 2 integrated keyhead transmitter remotes STX® Package:1 chrome grille and bumpers, 18" cast-aluminum wheels with bright center caps and LT275/65Rx18E BSW all-season tires (SRW), 17" polished forged-aluminum wheels (F-350 DRW), STX fender vent badges, and cruise control; DRW with 6.7L diesel engine also includes a high-airflow grille XL Value Package:1 chrome bumpers, bright center caps on wheels (SRW only), and cruise control

XLT

XLT Premium Package1 (SuperCab™/Crew Cab): 18" chrome-like PVD aluminum wheels (SRW only);

chrome front tow hooks, mirror caps, door and tailgate handles, 6" angular step bars, and exhaust tip; halogen fog lamps; SecuriCode™ keyless entry keypad; rear under-seat storage; 8-way power driver’s seat with heat; 2-way manual passenger seat with heat; and Reverse Sensing System XLT Value Package:1 halogen fog lamps, SecuriCode keyless entry keypad, rear under-seat storage (SuperCab/Crew Cab), 8-way power driver’s seat, and Reverse Sensing System

LARIAT

LARIAT Black Package1 (Crew Cab SRW 4x4): 6" black-painted angular running boards;

20" high-gloss black-painted premium aluminum wheels with LT275/65Rx2OE OWL all-terrain tires; Agate Black-painted grille, mirror caps and fender vent surrounds; headlamps with black-painted surrounds (LED headlamps only); body-color bumpers; Tough Bed® spray-in bedliner;

and rear wheel-well liners LARIAT Ultimate Package1 (Crew Cab): Remote Start System, LED CHMSL, LED box lighting, remote tailgate release, tailgate step, Intelligent Access with push-button start, power-tilt/-telescoping steering column with memory, Ice Blue ambient lighting, heated and ventilated front seats, easy-entry/-exit driver’s seat with memory, memory feature for sideview mirrors and power-adjustable pedals, wireless charging pad (requires front bucket seats), and Voice-Activated Touchscreen Navigation System with HD Radio™ Technology, and integrated SiriusXM® Traffic and Travel Link® with 5-year subscription2

LARIAT Value Package:1 Remote Start System, LED CHMSL, LED box lighting, heated and ventilated front seats, easy-entry/-exit driver’s seat with memory, and memory feature for sideview mirrors and power-adjustable pedals

LARIAT/KING RANCH

Chrome Package:1 18" chrome-like PVD aluminum wheels (SRW only) and chrome front tow hooks, bumpers, mirror caps, door handles, 6" angular step bars, and exhaust tip; KING RANCH also includes a chrome tailgate appliqué

KING RANCH

KING RANCH Monochromatic Paint Package (requires Chrome Package): monochromatic paint and chrome bumpers; deletes Stone Gray two-tone lower accent color and Stone Gray wheel-lip moldings KING RANCH Ultimate Package: quad-beam LED headlamps, LED fog lamps, LED taillamps, twin-panel moonroof, tailgate step, power-deployable running boards, and multicontour front bucket seats with Active Motion®

XLT/LARIAT/KING RANCH/PLATINUM

TREMOR® Off-Road Package1 (Crew Cab SRW 4x4 with 6.75' box): 18" low-gloss black-painted aluminum wheels, 35" LT285/75Rx18 off-road tires and spare tire, wheel-lip moldings, unique front air dam, limited-slip front differential, electronic-locking rear differential, unique front springs for increased ride height, front and rear performance shocks, transfer case and fuel tank skid plates, extended axle vent tubes, low-profile off-road running boards,…