R-7278 VDG Tiebacks Addendum 3.pdf

R-7278 Addendum No. 03

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

September 9, 2026

ADDENDUM NO. 03

PLANS AND SPECIFICATIONS NO. R-7278

NAPLES SEAWALL – VISTA DEL GOLFO TIEBACKS

IN THE CITY OF LONG BEACH, CALIFORNIA

NOTICE TO HOLDERS OF PLANS AND SPECIFICATIONS

Please note the following changes, clarifications, and additions:

1. QUESTIONS AND RESPONSES

2. SPECIFICATIONS

3. ATTACHMENTS

CONTACT: Before the Bid opening, prospective Bidders shall direct any communications regarding this Work to:

City of Long Beach, Department of Public Works Project Management Bureau 5th Floor, City Hall 411 W. Ocean Boulevard Long Beach, CA 90802 Attention: Stephen Figueira E-mail: Stephen.Figueira@longbeach.gov / TidelandsCIP@longbeach.gov

Communications may be written or oral, but the City is not bound by any oral interpretation of the Contract Documents made by any City employee, nor does the City guarantee the accurate transcription of oral questions.

PREPARED BY: Stephen Figueira

ACKNOWLEDGED BY:

Company Name

Print Name Title

Signature Date mailto:Stephen.Figueira@longbeach.gov mailto:TidelandsCIP@longbeach.gov

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

PLANS AND SPECIFICATIONS NO. R-7278

NAPLES SEAWALL – VISTA DEL GOLFO

TIEBACKS

IN THE CITY OF LONG BEACH, CALIFORNIA

ADDENDUM NO. 03

01. QUESTIONS AND RESPONSES

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

1. QUESTIONS AND RESPONSES

1. Question: Section 14.2 Use of Apprentices, of the PLA states that apprentices MAY comprise up to 30% of each craft’s workforce. It was stated during the prebid meeting that apprentice requirements are 1 apprentice hour to 5 journeyman hours (20%). Please clarify what percentage of apprentice hours are required.

Response: Response: Both requirements apply but address two different issues:

PLA: Section 14.2 notes that Apprentices may comprise up to thirty percent (30%) of each craft's work force (calculated by hours worked).

Labor Compliance: Page A-4 references Section 1777.5 of the Labor Code, which states that contractors must maintain a ratio of 1 apprentice hour for every 5 journeyperson hours for each applicable craft or trade.

2. Question: Per Section 02 41 19, Part 3.1-A-1, contractor to contact City Marine Bureau to secure a launch permit 4 weeks prior to site work for the launching of marine equipment. Are there any costs associated with this permit?

Response: There will not be permit fees for this.

3. Question: Are there any specifications for vibration and noise monitoring that need to be met other than local ordinances?

Response: Yes. Please see revised specification Section 31 50 00 – Tieback Anchors, Section 3.8 Monitoring, included in this Addendum.

4. Question: Per section 05 50 00, Part 2.1-A, contractor is to engage a qualified engineer to design tieback anchor system. Is this still required with the provided tieback design provided in plans?

Response: The contractor shall submit shop drawings, stamped by a qualified professional engineer, that are in conformance with the provided specifications and construction drawings. Division J Section 05 50 00 Part 2.1A. shall be revised to read "Delegated Design: Engage a qualified professional engineer to stamp the shop drawings submittal."

5. Question: Additive bid items 17 – 19 call for the repair and painting of pile caps.

Please list the types of repairs and provide profile views of the repairs required.

Response:

Division C Bid sheet has been updated to reflect the information below.

Additive Area 1 (1-7 VDG) = 3 properties+ Street End Additive Area 2 (33-47 VDG) = 4 properties + Street End Additive Area 3 (55-97 VDG) = 8 properties

For each property and street end in the additive areas, assume 5 post pocket repairs per construction notes 4&5, continuous horizontal joint repair per construction note 6, 16 SF of spall repair per construction note 7, 8 LF of crack repair per construction note 8, painting per construction note 10, and 1x expansion joint reseal at every other address per construction note 9.

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

Docks, gangways and platforms will not be relocated adjacent to the additive area extents. Contractor shall factor working from private docks and protection of private docks into pricing.

6. Question: Per plan Sheet G-1, Geotechnical Design Notes, contractor to account for soil conditions described in the Geotechnical Engineering Memorandum. Please provide referenced Memorandum.

Response: The following documents have been included in this Addendum (see 03. Attachments).

• Geotechnical engineering memorandum "Vista del Golfo Seawall Tie-Back Repair 11 to 31 Vista del Golfo, Long Beach, California" dated May 13, 2025

• “Coastal Engineering Design Parameters, Vista Del Golfo Seawall Tieback Installation & Cap Repair” dated May 19, 2025

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

PLANS AND SPECIFICATIONS NO. R-7278

NAPLES SEAWALL – VISTA DEL GOLFO

TIEBACKS

IN THE CITY OF LONG BEACH, CALIFORNIA

02. SPECIFICATIONS

Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

SPECIFICATIONS

Please note the following updates to Specifications for the NAPLES SEAWALL – VISTA DEL GOLFO TIEBACKS (Specification Number R-7278):

• Division C Bid Documents – Bid Tab Form sheets C-1 and C-2, shall be replaced in its entirety with the attached document. See following sheets.

• Division J CSI Technical Specifications – Section 31 50 00 – Tieback Anchors, Section 3.8 Monitoring shall be added attached document. All existing subsequent sections shift accordingly. See following sheets.

Department of Public Works C-1 R-7278

City of Long Beach Division C – Bid Documents

BIDDER'S NAME: ______________________

BID TO THE CITY OF LONG BEACH

NAPLES SEAWALL – VISTA DEL GOLFO (VDG) TIEBACKS

In accordance with the Notice Inviting Bids for this Work in the City of Long Beach, California, to be opened on September 19, 2026, at 10:00 a.m., we offer to furnish all necessary labor, tools, materials, appliances and equipment for and perform all Work mentioned in the Notice Inviting Bids, in full compliance with Plans & Specifications No. R-7278 at the prices listed below.

We certify that we have examined the site and that the Bid is complete. By signing the Bid, we certify that the Contractor will not submit a claim based on failure to examine the site thoroughly.

The base bid total shall be used for determining the lowest bidder.

Note: Items designated (S) are “Specialty Items” in accordance with the City’s General Requirements, Section 2-3.2.

BASE BID

ITEM

NO.

ITEM DESCRIPTION

ESTIMATED

QUANTITY

UNIT

UNIT PRICE

(IN FIGURES)

ITEM

TOTAL

(IN

FIGURES)

1. Mobilization/Demobilization (not to exceed 10% of Base Bid Total)

1 LS

2. Temporary Security Fencing and Pedestrian Routing Signage

1 LS

3. Topographic Survey Monitoring

1 LS

4. Vibration and Noise Monitoring

1 LS

5. Pre-Construction Inspection and Report

1 LS

6. Dock, Gangway, and Platform Removal, Storage, Modification and Reinstallation and Utility Disconnection and Reconnection

8 EA

7. Tieback Anchor Installation (S)

71 EA

8. Tieback Anchor Grouting (S)

24 CY

9. Lightweight Cellular Concrete Injection

351 CY

10. Post Pocket Full Repair 37 EA stfigue Text Box Addendum 03

Department of Public Works C-2 R-7278

City of Long Beach Division C – Bid Documents

ITEM

NO.

ITEM DESCRIPTION

ESTIMATED

QUANTITY

UNIT

UNIT PRICE

(IN FIGURES)

ITEM

TOTAL

(IN

FIGURES)

11. Post Pocket Waterside Repair

7 EA

12. Grind and Patch Repair 330 LF

13. Pile Cap Spall Repair 231 SF

14. Pile Cap Crack Repair 55 LF

15. Reseal Expansion Joint 12 EA

16. Paint Pile Cap 330 LF

BASE BID TOTAL _______________________________________________

BID ADDITIVE ITEMS

ITEM

NO.

ITEM DESCRIPTION

ESTIMATED

QUANTITY

UNIT

UNIT PRICE

(IN FIGURES)

ITEM TOTAL

(IN

FIGURES)

17. Seawall Cap Repair & Paint 1 to 7 Vista del Golfo and Savona Walk street end)

185 LF

18. Seawall Cap Repair & Paint 33 to 47 Vista del Golfo and Iona Walk street end

205 LF

19. Seawall Cap Repair & Paint 55 to 97 Vista del Golfo

379 LF

BID ADDITIVE TOTAL _________________________________

TOTAL (BASE BID + BID ADDITIVES) _________________________________

We understand that these quantities are estimates only and are given solely for the purpose of facilitating the comparison of Bids, and that the Contractor’s compensation will be computed on the basis of the actual quantities in the completed Work.

DO NOT SUBMIT THIS FORM AS YOUR BID. BIDS ARE TO BE SUBMITTED

ELECTRONICALLY AS DESCRIBED IN DIVISION B.

(Continued on Next Page) stfigue

SECTION 31 50 00 – TIEBACK ANCHORS

31 50 00- 1 R - 7278

PART 1 - GENERAL

1.1 SUMMARY

A. Section includes tieback anchor system consisting of the anchor rod, anchor rod cap, grout and bearing bracket.

1.2 PREINSTALLATION MEETINGS

A. Preinstallation Conference: Conduct conference at the project staging yard on Ionia Walk.

1.3 ACTION SUBMITTALS

A. Shop Drawings: For tieback anchor system, prepared by or under the supervision of a qualified professional engineer. Include plans, elevations and sections of the proposed layout and details of the tieback anchors.

B. Delegated-Design Submittal: For tieback anchor system, including analysis data signed and sealed by the qualified professional engineer responsible for their preparation.

C. Grout Mix Design: For tieback anchor system.

D. Lightweight Cellular Concrete: For soil void fill.

1.4 INFORMATIONAL SUBMITTALS

A. Qualification Data: For the following:

1. Professional Engineer: Experience with providing delegated-design engineering services of the type indicated, including documentation that engineer is licensed in California.

B. Contractor Calculations: For tieback anchor system. Include analysis data signed and sealed by the qualified professional engineer responsible for their preparation.

C. Existing Conditions: Using photographs, show existing conditions of adjacent construction and site improvements that might be misconstrued as damage caused by inadequate performance of tieback anchor system. Submit before Work begins.

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31 50 00- 2 R - 7278

D. Driller Logs: Submit the original handwritten log and three (3) copies in typed format within two days of the completion of each hole. Separate logs must be made for each hole. At a minimum, include the following information on the logs or in the records for each hole:

1. Hole number or designation and elevation of top of hole.

2. Vertical inclination and horizontal angle (relative to normal to the wall face) of the hole.

3. Make and manufacture model designation of drilling equipment.

4. Dates and time when drilling operations were performed.

5. Time required for drilling each run.

6. Steel casing seat elevation, if required.

7. Geologic classification or description by depths of each stratigraphic unit encountered. This classification or description to be made immediately following the taking of the core.

8. Depth and elevation of hard drilling and other unusual occurrences.

9. Depth and elevation at which groundwater is encountered.

10. Depths and elevations at which drill water is lost and regained and amounts.

11. Depth and elevation of bottom of hole, determined by measuring the drill steel length.

E. Anchor Records: Upon completion of installation of each anchor, submit anchor records. Records must include: bond length, free stressing length of anchor, grout mix, grout pressure, bags of cement injected, a report of performance test or proof test results, and hole alignment surveys. The performance and proof test results must include measured lengths of drill holes and anchors, the loads and elongations recorded during testing, monitoring and stressing of the anchors, and graphs of test results.

1.5 CLOSEOUT SUBMITTALS

A. Record Drawings: Identify locations and depths of tie back anchors, capped utilities, abandoned-in-place support and protection systems, and other subsurface structural, electrical, or mechanical conditions.

1.6 FIELD CONDITIONS

A. Interruption of Existing Utilities: Do not interrupt any utility-serving facilities occupied by Owner or others unless permitted under the following conditions and then only after arranging to provide temporary utility according to requirements indicated:

1. Notify the City no fewer than 7 days in advance of proposed interruption of utility.

2. Do not proceed with interruption of utility without Owners written permission.

stfigue

31 50 00- 3 R - 7278

B. Survey Work: Engage a qualified land surveyor or professional engineer to survey adjacent existing buildings, structures, and site improvements; establish exact elevations at fixed points to act as benchmarks. Clearly identify benchmarks and record existing elevations. Coordinate survey with the City’s previous monitoring locations.

PART 2 - PRODUCTS

2.1 PERFORMANCE REQUIREMENTS

A. Delegated Design: Engage a qualified professional engineer to design tieback anchor system to resist all lateral loading and surcharge, including but not limited to, retained soil, groundwater pressure, adjacent building loads, adjacent traffic loads, construction traffic loads, material stockpile loads, and seismic loads, based on the following:

1. Compliance with OSHA Standards and interpretations, 29 CFR 1926, Subpart P.

2. Compliance with AASHTO Standard Specification for Highway Bridges or AASHTO LRFD Bridge Design Specification, Customary U.S. Units.

3. Compliance with requirements of authorities having jurisdiction.

4. Compliance with utility company requirements.

2.2 MATERIALS

A. Grout:

1. Cement

i. ASTM C150/C150M, V.

2. Water

i. Use fresh, clean, potable water free from injurious amounts of sewage, oil, acid, alkali, salts, or organic matter.

3. Aggregates

i. Fine aggregate for sand-cement grout must conform to ACI 301 and

ASTM C33/C33M for grout for backfilling holes. Aggregates must not contain substances which may be deleteriously reactive with alkalis in the cement.

4. Admixtures

i. Admixtures which control bleed, improve flowability, reduce water content and retard set may be used in the grout subject to approval. Any admixtures used must be compatible with the prestressing steel and mixed in accordance with the manufacturer's recommendations.

5. Grout Mixture for Anchors

i. Provide grout consisting of a homogenous, pumpable, stable mixture of

Portland cement and water. The water content must be the minimum stfigue

31 50 00- 4 R - 7278 necessary for proper placement but the water-cement ratio must not exceed 0.45 by weight.

ii. Base final proportions of materials on results of tests made on sample mixtures of grout. The minimum compressive strength of two-inch cubes, molded, cured, and tested in accordance with ASTM C109/C109M, must be 5000 psi at the time of stressing.

iii. Submit the proposed mix design for approval thirty days prior to installation of anchors with applicable test reports to verify that the grout mixture proportions selected will produce grout of the quality and minimum strength specified.

B. Tieback Anchors:

1. Anchor Bars: All-thread bar conforming to ASTM A615 Grade 75 or 80, or

ASTM A722. Couplers, nuts, spacers and other accessories must be in accordance with the anchor manufacturer's specifications and requirements.

2. Trumpet: ASTM A53/A53M Grade B of ASTM A500/A500M Grade B.

3. Bearing Plate: ASTM A36/A36M or ASTM A572/A572M Grade 50.

4. Bracket Assembly: Materials and fabrication in accordance with Section 05

50 00.

5. Corrosion Protection: Provide a tieback anchor assembly with Class I

Corrosion Protection per FHWA. Provide corrosion protection for the entire anchor and include anchorage covers and trumpets filled with corrosion inhibiting compound, or grout, and encapsulation of the free stressing length and bond length. Coat the bracket and all exposed steel components of the tieback anchor in accordance with Section 05 05 00.

C. Low Density Cellular Concrete

1. Provide low-density cellular concrete to fill voids between the existing concrete sheet pile panels and the soil behind them. The fill must must not contain gravel or rock and have a density of not more than 50 pcf, a compressive strength at 28 days of at least 100 psi, and a slump flow of at least 12 inches. The fill must be capable of placement at low pressures through a 1-inh diameter nozzle.

PART 3 - EXECUTION

3.1 INSTALLATION - GENERAL

A. Locate tieback anchor system clear of permanent construction, so that construction and finishing of other work is not impeded.

B. Install tieback anchor system to ensure minimum interference with roads, streets, walks, and other adjacent occupied and used facilities.

stfigue

31 50 00- 5 R - 7278

1. Do not close or obstruct streets, walks, or other adjacent occupied or used facilities without permission from City and authorities having jurisdiction.

2. Provide alternate routes around closed or obstructed traffic ways if required by authorities having jurisdiction.

3. Install tieback anchor system without damaging existing buildings, structures, and site improvements adjacent to excavation.

4. Account for existing concrete guide piles in the tieback installation plan.

3.2 PROJECT PHASING

The contractor shall follow the following project phasing:

A. Drill anchor holes

B. Install anchors and bearing brackets – hand tighten anchor nut

C. Install anchor grout

D. Install low density concrete

E. Anchor stressing and lock off

F. Concrete pile cap repairs

3.3 DRILLING

A. Drill holes at the locations and inclinations and to the minimum depth and diameters shown.

B. Drill holes through existing concrete with a diamond core bit.

C. Drill holes in soil by auger drilling or rotary drilling. Where required to prevent caving, provide holes with steel casing for support of the surrounding material.

D. Tolerances: Locate anchor holes within 2 inches vertically and 1 inch horizontally of the locations shown on the drawings. The alignment angle of the holes must be within 5 degrees of perpendicular to the wall in a horizontal plane and within

2.5 degrees of the specified angle in a vertical plane.

E. Concrete Panel Steel Reinforcement: Avoid existing steel reinforcement within concrete panel. If steel reinforcement is contacted, cease drilling operations and notify with Engineer.

stfigue

31 50 00- 6 R - 7278

3.4 ANCHOR INSTALLATION

A. Inspect all anchors prior to insertion in the hole and repair any damage to corrosion protection. If, in the opinion of the Engineer, the damage is not repairable, replace the damaged anchor.

B. Immediately before anchor insertion, clean the holes to remove drill cuttings and mud.

C. Insert anchors into holes in a manner that does not damage or deteriorate the anchor or the corrosion protection.

D. Grouting of Anchors

1. Place grout within the bond length such that the hole is filled in a manner to prevent air voids. Progressively fill the soil anchor hole and maintain it completely full from bottom to top of the bond zone until the grout has set.

Grouting of a soil anchor hole must be performed within 48 hours of the time the hole is drilled. The grouting procedure used must provide soil anchors which meet the specified design capacity. Post-grouting will normally result in higher bond values.

i. Gravity Grouting: Gravity grouting must proceed from the bottom of the hole to the top of the bond zone.

ii. Pressure Grouting: Determine the method of pressure grouting and prove with a demonstration anchor. Grout production anchors using the methods and target pressures that were used on the acceptable demonstration anchor. Grouting pressures and pumping rates must be controlled to prevent ground surface heave or fracturing. Incrementally increase grouting pressures until a refusal is reached or an acceptable amount of grout is pumped.

iii. Post-Grouting: Determine the number of phases of post-grouting and prove with a demonstration anchor. Grout production anchors using the methods and target pressures that were used on the acceptable demonstration anchor. Grouting pressures and pumping rates must be controlled to prevent ground surface heave or fracturing. Incrementally increase grouting pressures until a refusal is reached or an acceptable amount of grout is pumped.

2. Grout all holes within 48 hours of drilling. All anchors must be grouted on the same day they are placed in the hole. Do not leave ungrouted anchors in place overnight.

E. Bearing Bracket Installation: Install the bracket assembly over the anchor head and against the wall and secure to the wall as shown. If necessary, bevel the bearing plate, provide a beveled washer, or adjust the angle of end the pipe on the bracket so that the surface the nut bears on is perpendicular to the anchor, within 1 degree, and centered on the anchor. Anchor threads and nuts must be free of dirt, grout or other contaminants. Corrosion protection must be maintained intact at the anchorage and any damage must be repaired prior to stressing stfigue

31 50 00- 7 R - 7278

3.5 LOW DENSITY CELLULAR CONCRETE

A. General Requirements

1. Use gravity feed hopper system with 1” tremie tube and 1” rigid pipe to place low density cellular concrete between the back of the concrete pile cap and panels and the adjacent soil to fill void from the mudline elevation to the ground surface. Grout placement should be by gravity only without additional pressurization.

2. Hand mixing of low-density cellular concrete on-site is allowable.

B. Placement

1. Do not place cellular concrete until all anchors within 8 feet of the placement area have been installed and grouted. Install bearing plates and tighten nuts to a snug tight condition.

2. Place low density cellular concrete in the gap between the concrete pile cap and the soil to the mudline elevation approximately 13’ below ground surface or refusal.

3. Place low density cellular concrete in a continuous manner until low density cellular concrete is seen at the ground surface.

4. Do not stress anchors until cellular concrete has reached at least 50 percent of its design strength and an age of at least two days

3.6 STRESSING

A. General Requirements

1. Stress the anchors after the anchor grout in the bond zone has reached the specified strength, as verified by grout cube break.

2. Prior to stressing, surfaces upon which the stressing equipment is resting must be clean, and the stressing equipment must be aligned as nearly with the center of the hole as possible.

3. Apply an Alignment Load of 10 percent of the Design Load to the anchor prior to setting dial gauges.

4. Stress the anchor in accordance with the anchor manufacturer's recommendation, subject to the approval of the Engineer. Design and Lock-off loads are shown on the drawings. The maximum stress must never exceed 80 percent of the specified ultimate strength of anchor steel.

5. Conduct stressing of the anchors so that accurate elongation of the anchor steel can, at all times, be recorded and compared with the computations submitted and accepted.

6. Safety precautions must be taken to prevent workers from being behind or in front of the stressing equipment during stressing.

7. Submit a sequence for stressing of anchors for review and perform stressing of the anchors in accordance with the submitted sequence.

8. All stressing must be done in the presence of a representative of the Engineer.

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31 50 00- 8 R - 7278

9. At no time during the stressing and testing of an anchor must the stressing equipment be disconnected from the temporary stressing head or anchor.

B. Lock-off

1. After completion of all required tests, Return the load to the Alignment Load and apply the specified Lock-off Load to the anchor.

2. A lift-off test must be made to verify the load in the anchor tendon before the tendon is locked-off and the stressing equipment is removed.

i. The lift-off reading must be within five percent of the specified lock-off load.

ii. If the lift-off reading is not within five percent of the specified lock-off load, reset the anchorage and another lift-off reading must be made.

Repeat this procedure until a satisfactory lift-off reading is obtained.

3. After lock-off, the trumpet must be filled with grout and the anchor head protective cap installed.

3.7 FIELD QUALITY CONTROL

A. Survey-Work Benchmarks: Resurvey benchmarks daily during installation of tieback anchor system, excavation progress, and for project duration.

1. Maintain an accurate log of surveyed elevations and positions for comparison with original elevations and positions.

2. Promptly notify Engineer if changes in elevations or positions occur or if cracks, sags, or other damage is evident in adjacent construction.

B. Anchor Testing

1. Frequency: The first anchor installed and every tenth anchor following must be performance tested. All other anchors must be proof tested.

2. General Anchor Testing Requirements

i. During the stressing of each anchor, keep a record of gage pressure and of anchor elongation at each stage of stressing to the specified test or Lock-off Load, as applicable. The Test Load must not be exceeded.

ii. Provide a qualified California registered Professional Engineer to evaluate the anchor test results and determine the acceptability of the anchors in accordance with the criteria indicated hereunder.

iii. Final acceptance of each anchor will be made by the Engineer. All tests must be run in the presence of the Engineer or his representative.

3. Demonstration Anchor: The first anchor installed must be designated as a demonstration test anchor. Use demonstration test anchor to verify the bond strength of anchor and the adequacy of the anchor design and installation procedures.

4. Performance Test

i. Performance testing consists of cyclically and incrementally loading and unloading the anchor, and conducted in accordance with PTI DC35.1, Paragraph 8.3.2.

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31 50 00- 9 R - 7278

ii. Make measurements of the elongation of prestressing steel in accordance with PTI DC35.1. If the total movement at the end of 10 minutes at the Test Load exceeds 0.040 inch, the Test Load must be held an additional 50 minutes and the movement readings must be taken at the interval specified in PTI DC35.1, Paragraph 8.3.2.

iii. Submit test records, including plots and graphical analysis of test data upon acceptance of each performance tested anchor.

iv. If the performance test criteria are not met, the Contractor shall replace the anchor or enhance the existing anchor capacity by post-grouting or other acceptable method. The performance test shall then be carried out on the new or post-grouted anchor. This procedure will be repeated until the required test criteria are met. Once the test criteria are met, an additional performance test shall be performed on an anchor in selected by the Engineer.

5. Proof Test

i. Proof testing consists of incrementally loading the anchor and conducted in accordance with PTI DC35.1, Paragraph 8.3.3.

ii. Make measurements of the elongation of prestressing steel in accordance with PTI DC35.1. If the total movement at the end of 10 minutes at the Test Load exceeds 0.040 inch, the Test Load must be held an additional 50 minutes and the movement readings taken at the interval specified in PTI DC35.1, Paragraph 8.3.3.

iii. Submit test records, including plots and graphical analysis of test data upon acceptance of each proof tested anchor.

iv. If the proof test criteria are not met, the Contractor shall replace the anchor or enhance the existing anchor capacity by post-grouting or other acceptable method. The proof test shall then be carried out on the new or post-grouted anchor. This procedure will be repeated until the required test criteria are met.

v. Compare the proof test results with similar anchors in which performance tests have been performed. If any significant variation from the proof tests occurs, the Engineer may require additional performance tests.

3.8 MONITORING

A. Monitor and maintain tieback anchor system.

B. Continuously monitor vibrations, settlements, and movements to ensure stability of site and to ensure that damage to permanent structures is prevented.

C. The Contractor shall provide vibration and noise monitoring for the following work:

i. Demolition – Breaker bars, skip loader, jack hammers, bobcat, etc.

ii. Tie-Back Anchor Hole Drilling

iii. Production Tie-Back Anchors stfigue

31 50 00- 10 R - 7278

iv. Concrete repair preparation

v. Grading/Compaction - skip loader, bobcat, vibratory equipment, etc.

D. Continuous vibration and noise monitoring is required during the demolition and new construction phases of the project as follows:

i. The maximum vibration levels with respect to adjacent improvements are:

ii. Residential Structures = 0.75”/sec Peak Particle Velocity (PPV)

iii. Contractor shall submit a Vibration Monitoring Plan prepared by a properly qualified third-party vibration specialist for approval by the City and shall include the following at a minimum:

iv. Means and Methods - Seismographs - A minimum of 2 seismographs shall be utilized to monitor vibration generated at the site. The seismographs shall remote capabilities and shall have a local alarm.

v. Locations – the project seismographs shall be set up on adjacent private and/or City properties during construction activities. The location of the seismographs will be determined by the contractor based on where construction activities are to be performed. At a minimum, the location of one seismograph should be placed adjacent to the closest residential structure.

vi. Threshold Notifications – Seismographs shall be programmed to notify the on-site contractor and vibration consultants when PPV levels exceed 0.50 inch/sec at residential structures. If vibration levels exceed a PPV of 0.50 in/sec, the contractor shall evaluate their construction procedures to minimize vibration. If the vibration levels exceed the maximum threshold limit for the project, all construction activities in the area shall cease until revised methods can be implemented to meet specifications.

vii. Reporting – Vibration monitoring equipment for the project shall be capable of providing continuous monitoring of the peak particle velocity and a permanent record of all monitoring. A report shall be submitted to the City on a weekly basis with will list the date, seismograph location and recorded PPV. Copies of the daily seismographic records shall be submitted with the report.

viii. Daily Record/Log – The contractor shall maintain a compliant log and make available to the City upon request. Log shall document all complaints received, including the date, time complaint was made, nature of complaint and actions taken. Responses to complaints shall be made within 24 hours in writing.

ix. Noise generated by construction shall not exceed 65 dB at any active nesting site within five hundred feet of project site for black-crowned night herons, great blue herons, snowy egrets, raptors, or other sensitive species. If construction noise exceeds 65 dB, then alternative methods of construction or other sound mitigation measures shall be used as necessary to achieve the required dB threshold levels. If these sound mitigation measures do not reduce noise levels, construction within five hundred fee of the nesting trees shall cease and shall not recommence until either new sound mitigation can be employed or nesting is complete.

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31 50 00- 11 R - 7278

3.9 REPAIRS

A. Promptly correct detected bulges, breakage, or other evidence of movement to ensure that tieback anchor system remains stable.

B. Promptly repair damages to adjacent facilities caused by installation or faulty performance of tieback anchor system.

PART 4 - PAYMENT

A. Payment for Tieback Anchor Installation will be made at the unit price bid for which payment shall constitute full compensation for fabrication, installation and testing of each and Tieback Anchor, including concrete panel coring, waler system and other incidental operations, completed in place.

B. Payment for Lightweight Cellular Concrete Injection will be made at the unit price bid for which payment shall constitute full compensation for procuring materials, injecting, forming, curing and other incidental operations, completed in place.

C. Payment for Tieback Anchor Grouting will be made at the unit price bid for which payment shall constitute full compensation for procuring material, mixing/batching, forming, curing and other incidental operations, completed in place.

END OF SECTION

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Department of Public Works 411 West Ocean Boulevard, 5th Floor Long Beach, CA 90802

(562) 570-5578

PLANS AND SPECIFICATIONS NO. R-7278

NAPLES SEAWALL – VISTA DEL GOLFO

TIEBACKS

IN THE CITY OF LONG BEACH, CALIFORNIA

03. ATTACHMENTS

21700 Copley Drive # 200 * Diamond Bar, CA 91765 * Tel: 909-680-7777

TO: COMPANY: DATE:

Rafael Holcombe, P.E. Tetra Tech May 13, 2025

FROM: COMPANY: PHONE NUMBER:

Douglas Bell, P.E., G.E. Tetra Tech

(909) 655 3223

RE:

Geotechnical Engineering Memorandum

Vista del Golfo Seawall Tie-Back Repair

11 to 31 Vista Del Golfo, Long Beach, California

1. INTRODUCTION

This memorandum summarizes the geotechnical evaluation performed to support tie-back repair design for the seawall located adjacent to residential properties in the Naples district of Long

Beach. The interim repairs will extend between 11 and 31 Vista del Golfo, a total of 9 residential properties. The scope of work to prepare this memorandum included the following:

• Review of existing geotechnical and inspection reports pertinent to the subject area.

• Recommendations for new post-tensioned tie-back anchors.

• Recommendations for earth pressures to be used for evaluating the existing wall and designing the new tie-back anchors.

• Recommendations for tie-back anchor testing during construction.

Geotechnical information to support this effort was taken from existing investigation reports. No additional geotechnical exploration or testing was performed for this study.

2. PROJECT DESCRIPTION

2.1. HISTORICAL PERSPECTIVE

The existing seawall within the study area was installed in 1938/1939 and consisted of precast concrete sheet piles with a cast-in-place concrete cap. Lateral support to the wall was provided by steel tie-rods connecting the cap with concrete anchors piles installed parallel to and 18 feet landward of the seawall. The anchor piles were 1.5 inches in diameter, 24 feet deep and installed

10 feet center to center.

The existing pile cap was raised in the 1960’s to counteract the effects of land subsidence caused by oil extraction. Over the years, loss of soil from behind the wall, likely caused by weeping through openings in the joints between sheet pile panels, has been problematic. Rehabilitation efforts have been performed periodically in an attempt to address the soil loss and have included mud jacking, waterproofing, cement grout and polymer grout injection. Another increasing problem appears to be seaward tilting of the seawall.

Geotechnical Engineering Memorandum May 13, 2025

11 to 29 Vista del Golfo - Seawall Interim Repair TET 25-0283

In 2009, a comprehensive study of the seawall condition for the entire Naples area was performed by Transystems. The report recommended that the entire seawall be replaced. Subsequent studies recommended a robust steel sheet pile system installed to a sufficient depth to resist both static and seismic loading conditions. To date, this sheet pile replacement has only been completed in the first 2 of 6 phases. The current study area is programmed as Phase 6 of 6.

Concurrent with the seawall replacement plan, the City of Long Beach is implementing an interim repair program which includes leaving the existing concrete sheet pile panels in place and adding lateral support by installing post-tension tieback anchors. The restraining force of the tieback anchors would be imparted to the front of the existing wall using a corrosion-protected steel wale beam. This system has already been installed at several locations within the Naples district including a segment immediately to the west of the current project area, ending at 7 Vista del

Golfo. The proposed repair for the current project will be similar in concept to the tieback anchors recently constructed, with modifications to adapt to specific site constraints and soil conditions.

Tetra Tech personnel performed visual inspections of the subject area on June 20, 2024, August

29, 2024 as summarized in the Naples Island Seawalls Inspection Report (Tetra Tech, 2024) and

March 25, 2025 in support of this current memorandum. A summary of observations at selected points are summarized in Table 1. The location of the observation points are presented on the Site

Location Map, Plate 1.

Table 1

Summary of Observed Movement

Observation

Point

Number

8-29-2024

(Site Recon.)

Vista de Golfo

House Number

Horizontal Gap Measurement (inch)

NOTES

6/20/2024 8/29/2024 3/26/2025

P-1 23 0.50 0.50 0.63 Gap between planter border and seawall

P-2 23 0.88 0.88 0.88 Gap between brick planter wall and seawall

P-3 23 1.38 1.38 1.37 Gap between brick planter wall and seawall

P-4 27 2.25 2.38 2.75 Gap between planter border and seawall

P-5 27 5.00 4.13 4.69 Gap between planter border and seawall

P-6 31 1.63 1.63 1.75

Gap between edge of exposed aggregate slab and seawall

Observation

Point

Number

8-29-2024

(Site Recon.)

Vista de Golfo

House Number

Horizontal Gap Measurement (inch)

NOTES

6/20/2024 8/29/2024 3/26/2025

P-7 29 0.25 0.25 0.44

Opening in mortar of patio rock. Vertical offset 0.56"

The observations indicate that continuing movement is occurring at several areas along the seawall.

2.2. EXISTING GEOTECHNICAL INFORMATION

A geotechnical report, which was prepared for the Transystems evaluation, AESCO (2009), includes subsurface data relatively close to the project area. The closest boring from this study was located at the end of Savona Walk, west of the project site (Boring B-5). The AESCO report also included data from previous exploration performed by Kleinfelder in 2002. The closest boring from that investigation was located at the end of Ionia Walk, east of the project site (Boring KA-5).

Approximate locations of the borings are presented on the Site Location Map, Plate 1. The subsurface conditions encountered in these borings to the maximum depth of exploration of 30 feet consisted of loose to very loose silty sand and very soft to firm sandy silt. Groundwater was encountered approximately 2 to 3 feet below the ground surface. Standard Penetration Test (SPT) blowcounts in the borings suggest a friction angle of about 28 degrees for soils within the anticipated depth of the tieback anchors. Laboratory shear strength testing performed by AESCO indicate friction angles as low as 23 degrees.

3. DESIGN RECOMMENDATIONS

3.1. SEISMIC CONSIDERATIONS

Based on the review of the geotechnical data it is evident that the subsurface soils to a depth of at least 30 feet are liquefiable under seismic design conditions prescribed by the current California

Building Code. In the event of soil liquefaction, it is expected that significant ground deformation would occur that could cause large-scale distress to the seawall. The bonded length of the tieback anchors currently proposed for this project would be located within the potentially liquefiable soils and, therefore, cannot be relied upon to effectively resist movement of the wall during a design level earthquake. Therefore, it must be understood that the currently proposed interim repair design pertains to stabilizing the seawall under static loading conditions only.

3.2. WALL DESIGN PARAMETERS

The design static lateral earth pressures acting against the existing seawall with one row of tieback anchors are presented in Figure 1. The pressure diagram on Figure 1 includes loading from differential water level. It is recommended that a maximum potential differential groundwater head be estimated using a water depth of 2 feet below existing grade behind the seawall and the mean lower low tide level on the seaward side of the wall. Figure 1 also presents lateral pressure on the wall based on a uniform vertical surcharge behind the wall. Recommendations for specific point loads or loading that is offset from the back of the wall can be provided upon request.

3.3. ANCHOR LAYOUT AND DESIGN REQUIREMENTS

It is expected that the horizontal spacing of the tieback anchors will be based on optimizing load transfer to the existing sheet pile panels. A minimum horizontal spacing of 4 feet is recommended to minimize any bond stress reduction between adjacent anchors. Tieback anchors should be installed at an angle of at least 15 degrees but no more than 30 degrees, below the horizontal.

The unbonded length of the anchor, the distance between the anchor lock-off and the bonded zone should be a minimum of 10 feet and 15 feet for bar and strand anchors, respectively. In addition, the bonded zone of each anchor should begin a minimum distance of 5 feet behind a plane projected at an angle of 57.5 degrees from horizontal up from the base of the wall. The anchors must be unbonded in the zone between this plane and the back of the wall. The location of the bonded zone should also allow for at least 15 feet of soil cover over the midpoint of the zone. The above requirements are depicted on Figure 2.

Utilizing typical values presented by Federal Highway Authority (FHWA) Tie-Back Design manual, FHWA (1999) an ultimate bond strength of 12 psi for a pressure grouted anchor is considered achievable within the on-site soils.

It should be noted that the soil stratigraphy within the potential bonded zone is anticipated to be composed of loose to very loose sands and soft to firm silt. Given these conditions, it should be anticipated that substantial bonded lengths may be needed to achieve the required capacities.

To preclude overstressing of the near surface soils behind the wall during testing and/or lock-off of the anchors, the horizontal component of the maximum load of the anchor (Fh) should be limited to:

Fh < (1.125Kpɣh1 2s) x (1/ FS)

Where:

Fh = maximum allowable horizontal component of the anchor force (lbs)

Kp = ultimate coefficient of passive pressure = 3.4 ɣ = unit weight of soil = 100 lbs/ft3 (average effective unit weight of upper soils) h1 = depth to upper row of anchors from top of wall (feet) s = anchor horizontal spacing (feet)

FS = Factor of Safety (min. 1.5)

3.4. COMPRESSIVE CAPACITY OF EXISTING CONCRETE SHEET PILES

It is recommended that an allowable average skin friction of 95 psf and an allowable end bearing of 1,700 psf be used to evaluate the resistance of the existing concrete sheet pile panels to vertical loading from testing and lock-off of the tie-back anchors. The skin friction may be applied to both sides of the panels below the design scour elevation.

3.5. ANCHOR INSTALLATION AND TESTING

The locations and depths of all underground utilities should be thoroughly checked prior to design and installation of the tieback anchors. Caving of the anchor holes, particularly within saturated, loose deposits, should be anticipated and provisions, such as the use of hollow stem auger or temporary casing, utilized to minimize such caving.

The bonded portion of the anchors should be filled with grout placed from the tip up, and the grout should extend from the tip of the anchor to the defined limit of the bonded zone. To minimize the potential for caving, it is suggested that the portion of the anchor shaft within the unbonded length be backfilled with sand before testing the anchor. This portion of the shaft should be filled tightly and flush with the face of the excavation. The sand backfill may contain a small amount of cement to allow the sand to be placed by pumping. For post-grouted anchors the unbonded length may be filled with grout to the back face of the wall provided the tieback strands or bars are enclosed in sheathing.

The capacities of anchors should be verified by testing during construction. The tieback proof and performance testing program should be in compliance with the latest version of Post-Tensioning

Institute (PTI) guidelines PTI DC35.1-14, “Recommendations for Prestressed Rock and Soil

Anchors”.

Performance or proof testing should be performed on all anchors. Both testing methods include recording anchor movement for various loading increments, however, performance testing also includes several cycles of load testing and measurement of residual movement of the anchor for each cycle. At least 10 percent of the anchors should be performance tested to 1.33 times the design load. The remaining anchors should be proof loaded to 1.33 times the design load per PTI guidelines.

For both the proof and performance testing the acceptance criteria should be a total movement of less 1 mm (0.04 inch) over a period of 10 minutes under the full test load of 1.33 times the design load. If the movement is in excess of 1 mm then the test load should held for an additional 50 minutes with readings taken every 10 minutes. If more than 1 mm is recorded over the final 10-minute period the test result should be deemed unacceptable.

Anchors that do not meet any of the testing criteria should be either rejected or locked off at a load not exceeding 50 percent of the load where the anchor stabilizes in 10 minutes. In the latter case, the reduced capacity must be evaluated and accepted by the Structural Engineer and the

Geotechnical Engineer.

After a satisfactory test, each anchor should be locked-off at the design load. This should be verified by rechecking the load in the anchor by a lift-off test. The lift-off load needed to unseat the wedge plate should be at least 90 percent of the design load.

Due to the presence of residential properties adjacent to the wall and above the anticipated anchor bond zone it is recommended that monitoring of the ground surface and existing structures be performed during construction. Survey monuments should be established on the existing seawall, planters, walkways and foundations of adjacent residences. The monuments should be continuously surveyed during the installation, testing and lock-off of the anchors. Because of gaps between the seawall and adjacent ground it should be expected that the sheet piles will deflect as the anchors are loaded. The Structural Engineer should provide a limit for the allowable movement. If discernible horizontal or vertical movement of the walkways or building foundations are measured, the anchor installation process should be discontinued and alterative design and/or construction methods be investigated.

3.6. CORROSION

As seawater intrudes behind the wall and is subject to tidal fluctuations, it is recommended that

Class I corrosion protection per FHWA (1999) be used for the tie-back anchors. This will require double encapsulation of anchor strands or bars. Exposed steel used for load plates or waler beams should be galvanized or utilize other means of protection for an aggressive marine environment.

In addition, any reinforced concrete used in the repair design should include a mix design and reinforcement cover applicable for an aggressive marine environment.

CLOSURE

The conclusions, recommendations and opinions expressed in this memorandum are based on

Tetra Tech’s review of background documents and on information obtained from field explorations and associated laboratory testing performed by others.

Due to the limited nature of the field explorations, conditions not observed and described in this report may be present on the site. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation and laboratory testing can be performed upon request. It should be understood that conditions different from those anticipated in this report may be encountered during construction.

Tetra Tech has endeavored to perform its evaluation using the degree of care and skill ordinarily exercised under similar circumstances by reputable civil, structural, and geotechnical professionals with experience in this area in similar soil conditions. No other warranty, either expressed or implied, is made as to the conclusions and recommendations contained in this report.

Respectfully submitted, Tetra Tech

Douglas Bell, G.E.

Principal Geotechnical Engineer

Distribution: pdf by email rafael.holcombe@tetratech.com

REFERENCES

AESCO 2009, Geotechnical Report, Naples Island Seawall Repair, Communications Facility, Long Beach, CA, AESCO Project No. 20082145-A4805, revision dated

February 5, 2009.

FHWA 1999, Federal Highway Administration Design Manual: Geotechnical Engineering

Circular No 4, Ground Anchors and Anchored Systems, Report No. FHWA-IF-99-015.

Dated June 1999.

Tetra Tech 2024, Site Inspection – 19 through 31 Vista Del Golfo – Memo#2, dated

September 16, 2024.

PLATE

B-5

KA-5

19 23 25 27 29 31 33 35 41 47

TET 25-283E APRIL 2025 DL

PLATE 1

VISTA DEL GOLFO - SEAWALL REPAIR

SITE LOCATION MAP

21700 Copley Drive, Suite 200, Diamond Bar, CA 91765

PROJECT NO.: DATE: DRAWN BY:

TETRA TECH

TEL 909.860.777 www.tetratech.com

P-7 P-6P-5P-4P-3P-2P-1

GRAPHIC SCALE:1''=

80'

80 160

EXPLANATION

(LOCATIONS APPROXIMATE)

B-5

KA-5

Boring (Kleinfelder, 2002)

Boring (Aesco, 2009)

Observation Points (Tetra Tech, 2024)

P-7

FIGURES

Maximum Scour Depth

W1

Rock Bolt Design Parameters (assuming 15’ of shored overburden underlain by 10’ of hard basalt)

10’

69° 47° 35°

1,875psf (15’ overburden pressure)

Critical angle based on preliminary SLOPE/W analysis

2,240lbs (lateral loads due to E80 loading)

5’

Basalt

600psf (vertical pressure due to E80 loading)

Range of Joint Dip Angles 35° to 69°

Joint Strength (assumed soil-filled) c = 50psf, θ = 32°

Full Hydrostatic Pressure

624psf (hydrostatic pressure)

Passive Earth Pressure

Active Earth Pressure

Surcharge Pressure

64 (W -W )2 1

ΔGW Pressure

24 H psf

H

2/3 H1

D

220 D psf 24 (H+D) psf

Tieback Anchor

2/3 (H-H )1

0.36 q psf q (psf)

H1

W2

Not to scale FIGURE 1

0.05q

1/3 H

Restrained Pressure

21700 Copley Drive, Suite 200, Diamond Bar, CA 91765 TEL 909.860.7777 www.tetratech.com

TET 25-283E

APR 2025

SCM

DB

JOB NO.

DATE

DRAWN BY

CHECKED BY

VISTA DEL GOLFO SEAWALL REPAIR – LONG BEACH, CA

DESIGN WALL PRESSURES

(ONE ROW OF TIEBACK ANCHORS)

JOB NO.

DATE

DRAWN BY

CHECKED BY

Maximum Scour Depth

W1

Rock Bolt Design Parameters (assuming 15’ of shored…