Attachment_7_Statement_of_Structural_Tests_and_Special_Inspections.pdf

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 1 of 16

Statement of Structural Tests and Special Inspections

National Park Service - Denver Service Center

Park: First State National Historic Park

PMIS: 240745

Project Name: Sheriff’s House

Structural Engineering Firm: Simpson Gumpertz & Heger

This Statement of Structural Tests and Special Inspections is being submitted as required by

Chapter 17 of the 2015 International Building Code (IBC-15). It includes the following:

1. Seismic requirements

2. Wind requirements

3. Qualification requirements for Inspectors and Testing Technicians

4. Listing of Required Structural Tests and Special Inspections

The Construction Contractor’s Quality Control Supervisor will provide copies of all special inspection reports and associated documentation to the Contracting Officer. The Construction

Contractor will be required to correct all deficiencies discovered in the Special Inspection and

Structural Testing program.

Prepared by:

Matthew Daw, PE

(Type or print name)

Signature Date PE or SE Stamp

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 2 of 16

Seismic and Wind Requirements

Seismic Requirements, IBC-15 Section 1704.3

Description of seismic-force-resisting system and designated seismic systems subject to special inspections:

The current project scope consists of repair and strengthening existing framing to support adaptive reuse live loads. The existing lateral system and lateral loads for the Sheriff’s House will not be changed as part of the current project scope. No special inspections of the lateral seismic system will be required.

Wind Requirements, IBC-15 Section 1704.3

Description of wind-force-resisting system and designated wind systems subject to special inspections:

The current project scope consists of repair and strengthening existing framing to support adaptive reuse live loads. The existing lateral system and lateral loads for the Sheriff’s House will not be changed as part of the current project scope. No special inspections of the lateral wind system will be required.

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 3 of 16

Instructions:

1. Place an “X” in the column titled “Required?” for all Special Inspections and Tests required for this project.

2. In the column marked “Required Qualifications” provide the qualifications for the special inspector, using the list beginning on page 4, for all required Structural Tests and Special

Inspections.

3. For those items listed as “Continuous,” continuous special inspection shall be as defined in Section 1702.1 and Chapter 2, IBC-15.

4. For those items listed as “Periodic” provide the minimum number of tests, i.e. 20% of all field welds, or the amount of work to be inspected (e.g. 10% of all wall surfaces).

5. Attach completed Statement of Structural Tests and Special Inspections to the end of the

Specification Section 01 40 00, Quality Requirements.

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 4 of 16

Qualification Requirements for Inspectors and Testing Technicians

PE/SE Structural Engineer – licensed PE or SE specializing in the design of buildings and structures

PE/GE Geotechnical Engineer – licensed PE specializing in soil mechanics and foundations

EIT Engineer-In-Training – graduate engineer who has passed the Fundamentals of engineering examination

American Concrete Institute (ACI) Certification

ACI-CCSI Concrete Construction Special Inspector

ACI-LTT Concrete Laboratory Testing Technician Level 1 or 2

ACI-STT Concrete Strength Testing Technician

ACI-FTT Concrete Field Testing Technician – Grade I

American Society of Non-Destructive Testing (ASNT) Certification

Non-Destructive Testing Technician – Level II or III

American Welding Society (AWS) Certification

AWS-CWI Certified Welding Inspector

Exterior Design Institute (EDI) Certification

EDI-EIFS Certified EIFS inspector

International Code Council (ICC) Certification

ICC-PCSI Prestressed Concrete Special Inspector

ICC-RCSI Reinforced Concrete Special Inspector

ICC-SSI Soils Special Inspector

ICC-SFSI Spray-applied Fireproofing Special Inspector

ICC-SMSI Structural Masonry Special Inspector

ICC-SSBSI Structural Steel and Bolting Special Inspector

ICC-SWSI Structural Welding Special Inspector

National Institute for Certification in Engineering Technologies (NICET) Certification

NICET-CT Concrete Technician – Levels I, II, III and IV

NICET-GET Geotechnical Engineering Technician - Levels I, II, III and IV

NICET-ST Soils Technician - Levels I, II, III and IV

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 5 of 16

Other

___O____ __Observe construction at random intervals (AISC Chapter N)_______

___P____ __Perform inspection at each instance (AISC Chapter N)______

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 6 of 16

Listing of Required Structural Tests and Special Inspections

R eq u ir ed

Structural Test or Special Inspection Required

Qualifications

C o n ti n u o u s

P er io d ic

F re q u en cy o f

P er io

T es t o r

In sp ec ti n

Steel Construction (ref: IBC-15 Section 1705.2, AISC 360-10 Chapter N, AISC 341-

10 Chapter J)

Prior to Welding (AISC 360-10 Table N5.4-1)

X 1. Welding procedure specifications (WPSs) available X

X 2. Manufacturer certifications for welding consumables available

X

X 3. Material identification (type/grade) X O

X 4. Welder identification system X O

5. Fit-up of groove welds (including joint geometry)

a. Joint preparation X

b. Dimensions (alignment, root opening, root face, bevel) X

c. Cleanliness (condition of steel surfaces) X

d. Tacking (tack weld quality and location) X

e. Backing type and fit (if applicable) X

6. Configuration and finish of access holes X

X 7. Fit-up of fillet welds

X a. Dimensions (alignment, gaps at root) X O

X b. Cleanliness (condition of steel surfaces) X O

X c. Tacking (tack weld quality and location) X O

X 8. Check welding equipment X O

During Welding (AISC 360-10 Table N5.4-2)

X 1. Use of qualified welders X O

X 2. Control and handling of welding consumables

X a. Packaging X O

X b. Exposure control X O

X 3. No welding over cracked tack welds X O

4. Environmental conditions

a. Wind speed within limits X

b. Precipitation and temperature X

5. WPS followed

a. Settings on welding equipment X O

b. Travel speed X O

c. Selected welding materials X O

d. Shielding gas type/flow rate X O

e. Preheat applied X O

f. Interpass temperature maintained (min. /max.) X O

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 7 of 16 u ir

Qualifications

C o n ti n u o u s

P er io q u

P er io t o r

In sp ec ti

X g. Proper position (F, V, H, OH) X O

h. Intermix of filler metals avoided unless approved (ref:

AISC 341-10)

X

X 6. Welding techniques

X a. Interpass and final cleaning X O

X b. Each pass within profile limitations X O

X c. Each pass meets quality requirements X O

After Welding (AISC 360-10 Table N5.4-3)

X 1. Welds cleaned X O

X 2. Size, length and location of welds X

X 3. Welds meet visual acceptance criteria

X a. Crack prohibition X

X b. Weld/base-metal fusion X

X c. Crater cross section X

X d. Weld profiles X

X e. Weld size X

X f. Undercut X

X g. Porosity X

X 4. Arc strikes X

X 5. k-area X

6. Backing removed and weld tabs removed (if required) X

X 7. Repair activities X

X 8. Document acceptance or rejection of welded joint or member

X

9. Placement of reinforcing or contouring fillet welds (if required) (ref: AISC 341-10)

X

10. Backing removed, weld tabs removed and finished, and fillet welds added (if required) (ref: AISC 341-10)

X

Nondestructive Testing (AISC 360-10 Section N5.5)

1. Risk Category II Structures - Perform Ultrasonic Testing on 10% of CJP groove welds in butt, T- and corner joints subject to transversely applied tension loading, in materials 5/16 in. thick or greater.

X

2. Risk Category III or IV Structures - Perform Ultrasonic

Testing on all CJP groove welds subject to transversely applied tension loading in butt, T- and corner joints, in materials 5/16 in. thick or greater.

X

3. Access Holes – Perform Magnetic Particle Testing or

Liquid Penetrant Testing when the flange thickness exceeds 2 in. for rolled shapes, or when the web thickness exceeds 2 in. for built-up shapes.

4. Welded Joints Subject to Fatigue X

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 8 of 16 u ir

Qualifications

C o n ti n u o u s

P er io q u

P er io t o r

In sp ec ti

Nondestructive Testing (AISC 341-10 Section J6.2)

1. k-area X

2. CJP Groove weld X

3. Lamellar tearing X

4. Beam cope and access hole X

5. Reduced beam section repair X

6. Weld tab removal X

Prior to Bolting (AISC 360-10 Table N5.6-1)

These inspections are not required for snug-tight joints

1. Manufacturer’s certifications available for fastener materials

X

2. Fasteners marked in accordance with ASTM requirements X

3. Proper fasteners selected for the joint detail (grade, type, bolt length if threads are to be excluded from shear plane)

X

4. Proper fasteners selected for the joint detail (grade, type, bolt length if threads are to be excluded from shear plane)

X

5. Connecting elements, including the appropriate faying surface condition and hole preparation, if specified, meet applicable requirements

X

6. Pre-installation verification testing by installation personnel observed and documented for fastener assemblies and methods used

X

7. Proper storage provided for bolts, nuts, washers and other fastener components

During Bolting (AISC 360-10 Table N5.6-2)

These inspections are not required for snug-tight joints.

These inspections are not required for pretensioned joints and slip-critical joints, when the installer is using the turn-of-nut method with matchmarking techniques, the direct-tension-indicator method, or the twist-off-type tension control bolt method.

1. Fastener assemblies, of suitable condition, placed in all holes and washers (if required) are positioned as required

X

2. Joint brought to the snug-tight condition prior to the pretensioning operation

X

3. Fastener component not turned by the wrench prevented from rotating

X

4. Fasteners are pretensioned in accordance with the RCSC

Specification, progressing systematically from the most rigid point toward the free edges

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 9 of 16 u ir

Qualifications

C o n ti n u o u s

P er io q u

P er io t o r

In sp ec ti

After Bolting (AISC 360-10 Table N5.6-3)

Document acceptance or rejection of bolted connections X

Other Inspection Tasks (AISC 360-10 Section N5.7)

X 1. Verify compliance of fabricated steel with the details shown on the approved shop drawings.

X 1 time

X 2. Verify compliance of the erected steel frame with the details shown on the approved erection drawings, including braces, stiffeners, member locations and joint details.

X P

X 3. Anchor rods and other embedments support structural steel

X a. Verify the diameter, grade, type and length of the anchor rod or embedded item.

X P

X b. Verify the extent or depth of embedment into the concrete.

X P

4. RBS requirements, if applicable (ref: AISC 341-10)

a. Contour and finish X

b. Dimensional tolerances X

5. Protected zone—no holes and unapproved attachments made by fabricator or erector, as applicable (ref: AISC

341-10)

X

6. H-piles - Protected zone—no holes and unapproved attachments made by the responsible contractor, as applicable (ref: AISC 341-10)

Cold-formed Steel Deck (IBC-15 1705.2.2)

1. Special inspections in accordance with QA/QC-2011

Standard for Quality control and Quality assurance for

Installation of Steel Deck

Open-Web steel Joists and Joist Girders (IBC-15 Table 1705.2.3)

1. Installation of open-web steel joists and joist girders

a. End connections – welding or bolted X

b. Bridging – horizontal or diagonal

1. Standard bridging X

2. Bridging that differs from the SJI specifications listed in Section 2207.1

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 10 of 16

Inspection of Composite Structures Prior to Concrete Placement (AISC 341-10 Table J9-1)

1. Material identification of reinforcing steel (Type/Grade) X

2. Determination of carbon equivalent for reinforcing steel other than ASTM A706

X

3. Proper reinforcing steel size, spacing and orientation X

4. Reinforcing steel has not been rebent in the field X

5. Reinforcing steel has been tied and supported as required X

6. Required reinforcing steel clearances have been provided X

7. Composite member has required size X

Inspection of Composite Structures During Concrete Placement (AISC 341-10 Table J9-2)

1. Concrete: Material identification (mix design, compressive strength, maximum large aggregate size, maximum slump)

X

2. Limits on water added at the truck or pump X

3. Proper placement techniques to limit segregation X

Inspection of Composite Structures After Concrete Placement (AISC 341-10 Table J9-3)

1. Achievement of minimum specified concrete compressive strength at specified age

Cold-formed Steel Trusses Spanning 60-feet or Greater (ref: IBC-15 Section 1705.2.4)

1. Verify temporary installation restraint/bracing installed in accordance with the approved shop drawings.

2. Verify permanent individual truss member restraint/bracing installed in accordance with the approved shop drawings.

Concrete Construction (ref: IBC-15 Table 1705.3) X 1. Inspect reinforcing steel, including prestressing tendons, and placement.

X

P

2. Inspection of reinforcing steel welding in accordance with

Steel Construction section above.

X 3. Inspection of anchors cast in concrete. X P

X 4. Inspection of anchors post-installed in hardened concrete members.

X 5. Verify use of approved design mix. X P

X 6. Prior to placement fabricate specimens for strength tests, perform slump and air content tests, and determine the temperature of the concrete.

7. Inspect concrete and shotcrete placement for proper application techniques.

X 8. Inspect for maintenance of specified curing temperature and techniques.

X

O

9. Inspection of prestressed concrete:

a. Application of prestressing forces X

b. Grouting of bonded prestressing tendons in the seismic-force-resisting system.

10. Erection of precast structural members X

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 11 of 16

11. Verification of in-situ concrete strength, prior to stressing of tendons in post-tensioned concrete and prior to removal of shores and forms from beams and structural slabs.

X 12. Inspection formwork for shape, location and dimensions of the concrete member being formed.

Masonry Construction (ref: IBC-15 Section 1705.4)

1. Inspect masonry construction in accordance with IBC-15

Section 1705.4 and TMS 602-13/ACI 530.1-13/ASCE 6-

13 Article 1.6.

Level A Quality Assurance

Tests: None.

X Inspection: Verify compliance with the approved submittal and project specifications.

O

Level B Quality Assurance

Tests:

1. Verify slump flow and Visual Stability Index (VSI) as delivered to the project site in accordance with TMS 602-

13/ACI 530.1-13/ASCE 6-13 Specification Article

1.5B.1.b.3 for self-consolidating grout.

2. Verify f’m and f’aac in accordance with TMS 602-13/ACI

530.1-13/ASCE 6-13 Specification Article 1.4B prior to construction, except where specifically exempted.

Inspection:

1. Verify compliance with the approved submittals and project specifications.

2. At the start of masonry construction, verify:

a. Proportions of site-prepared mortar. X

b. Construction of mortar joints. X

c. Grade and size of prestressing tendons and anchorages.

d. Location of reinforcement, connectors, prestressing tendons and anchorages.

e. Prestressing technique. X

f. Properties of thin-bed mortar for AAC masonry.

(Continuous inspection is required for the first 5000 square feet of AAC masonry. Periodic inspection is required after the first 5000 square feet of AAC masonry.)

X X

3. Prior to grouting, verify:

a. Grout space is clean. X

b. Grade, type and size of reinforcement and anchor bolts, and prestressing tendons and anchorages.

c. Placement of reinforcing and connectors, and prestressing tendons and anchorages.

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 12 of 16

d. Proportions of site-prepared grout and prestressing grout for bonded tendons.

e. Construction of mortar joints. X

4. During masonry construction, verify:

a. Size and location of structural members. X

b. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames, or other construction.

c. Welding of reinforcement. X

d. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).

e. Application and measurement of prestressing force. X

f. Placement of grout and prestressing grout for bonded tendons is in compliance.

g. Placement of AAC masonry units and construction of thin-bed mortar joints. (Continuous inspection is required for the first 5000 square feet of AAC masonry. Periodic inspection is required after the first 5000 square feet of AAC masonry.)

X X

5. Observe preparation of grout specimens, mortar specimens and/or prisms.

Level C Quality Assurance

Tests:

1. Verify f’m and f’aac in accordance with TMS 602-

13/ACI 530.1-13/ASCE 6-13 Specification Article 1.4B prior to construction, and for every 5000 square feet during construction.

2. Verify proportions of materials in premixed or pre-blended mortar, prestressing grout, and grout other than self-consolidating grout as delivered to the project site.

3. Verify slump flow and Visual Stability Index (VSI) as delivered to the project site in accordance with TMS 602-

13/ACI 530.1-13/ASCE 6-13 Specification Article

1.5B.1.b.3 for self-consolidating grout

Inspection:

1. Verify compliance with the approved submittals and project specifications.

2. Verify:

a. Proportions of site-prepared mortar, grout and prestressing grout for bonded tendons

b. Grade, type and size of reinforcement and anchor bolts, and prestressing tendons and anchorages

c. Placement of masonry units and construction of mortar joints.

d. Placement of reinforcement, connectors and prestressing tendons and anchorages.

e. Grout space prior to grouting. X

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 13 of 16

f. Placement of grout and prestressing grout for bonded tendons.

g. Size and location of structural elements. X

h. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames or other construction.

i. Welding of reinforcement. X

j. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).

k. Application and measurement of prestressing force. X

l. Placement of AAC masonry units and construction of thin-bed mortar joints.

m. Properties of thin-bed mortar for AAC masonry. X

3. Observe preparation of grout specimens, mortar specimens and/or prisms.

Wood Construction (ref: IBC-15 Section 1705.5)

1. Inspect prefabricated wood structural elements in accordance with Section 1704.2.5

2. High load diaphragms:

a. Verify sheathing grade and thickness. X

b. Verify nominal size of framing members at adjoining panel edges.

c. Verify nail or staple diameter and length. X

d. Verify number of fastener lines. X

e. Verify spacing between fasteners in each line and at panel edges.

3. Shearwalls:

a. Verify sheathing grade and thickness. X

b. Verify nominal size of framing members at adjoining

c. Verify nail or staple diameter and length. X

d. Verify number of fastener lines. X

e. Verify spacing between fasteners in each line and at

f. Location and size of holdowns. X

4. Verify nailing, bolting, anchoring and fastening of:

a. Drag struts and collectors. X

b. Braces. X

c. Hold-downs. X

5. Metal-plate-connected wood trusses spanning 60 feet or greater:

a. Verify temporary installation restraint/bracing installed in accordance with the approved shop drawings.

b. Verify permanent individual truss member restraint/bracing installed in accordance with the approved shop drawings.

6. Sistering of existing wood framed members

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 14 of 16

X a. Verify size of new sisters X

X b. Verify connections of sister to existing member X

Soils (ref: IBC-15 Table 1705.6)

X 1. Verify materials below shallow foundations are adequate to achieve the required bearing capacity.

X

O

X 2. Verify excavations are extended to proper depth and have reached proper material.

X

O

3. Perform classification and testing of compacted fill materials.

4. Verify use of proper materials, densities and lift thicknesses during placement and compaction of compacted fill.

5. Prior to placement of controlled fill, observe subgrade and verify that site has been prepared properly.

Driven Deep Foundation Elements (ref: IBC-15 Table 1705.7)

1. Verify materials, sizes and lengths. X

2. Determine capacities of test elements and conduct additional load tests when required. Refer to project specifications.

3. Observe driving operations and maintain complete and accurate records for each element.

4. Verify element locations and plumbness. X

a. Verify type and size of hammer. X

b. Record number of blows per foot of penetration. X

c. Determine required penetration to achieve specified capacity.

d. Record pile tip and butt elevations. X

e. Document any damage to any foundation element. X

5. For steel piling, perform additional inspection in accordance with Section 1705.2 and AISC 341-10, Table

J10-1.

6. For concrete elements and concrete-filled elements, perform additional inspections in accordance with

Section 1705.3.

7. For specialty elements, perform additional inspections as required in the project specifications.

Cast-In-Place Deep Foundations (ref: IBC-15 Table 1705.8)

1. Observe drilling operations and maintain complete and accurate records for each element.

2. Verify element locations and plumbness. X

a. Verify element diameter. X

b. Verify bell diameter (if applicable). X

c. Verify element lengths. X

d. Verify embedment depth into bedrock (if applicable).

e. Verify adequate end-bearing strata capacity. X

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 15 of 16

f. Record concrete or grout volumes. X

3. For concrete elements, perform additional inspections in accordance with Section 1705.3.

Helical Piles (ref: IBC-15 Section 1705.9)

1. Verify pile locations X

a. Verify installation equipment used. X

b. Verify pile dimensions. X

c. Verify tip elevations. X

d. Verify final depth. X

e. Verify final installation torque. X

f. Other data as required by the project specifications. X

Wind Resistance (ref: IBC-15 Section 1705.11)

1. Provide inspections when required by Section 1705.11.

Seismic Resistance (ref: IBC-15 Section 1705.12)

1. Provide inspections when required by Section 1705.12.

Testing and Qualification for Seismic Resistance (ref: IBC-15 Section 1705.13)

1. Test and qualify seismic resistance in accordance with

IBC-15 Section 1705.13 and the project specifications.

Sprayed Fire-Resistant Materials (ref: IBC-15 Section 1705.14)

1. Inspect sprayed fire-resistant materials in accordance with

IBC-15 Section 1705.14 and the project specifications.

Mastic and Intumescent Fire-Resistant Coatings (ref: IBC-15 Section 1705.15)

1. Perform inspections in accordance with AWCI 12-B and

IBC-15 Section 1705.15.

Exterior Insulation and Finish Systems (EIFS) (ref: IBC-15 Section 1705.16)

1. Perform inspections in accordance with project specifications and IBC-15 Section 1705.16.

Fire-resistant Penetrations and Joints (ref: IBC-15 Section 1705.17)

1. Perform inspections in accordance with project specifications and IBC-15 Section 1705.17.

Smoke Control (ref: IBC-15 Section 1705.18)

1. Perform testing in accordance with project specifications and IBC-15 Section 1705.18.

Post Installed Adhesive Anchors (ref: ACI Chapter 17) X 1. Review installer qualifications X O

FRST-240745 Statement of Structural Tests and Special Inspections, 10-14-19 Page 16 of 16

X 2. Verify that existing reinforcing steel is not cut when drilling holes for concrete

X 3. Verify drilled holes are the proper diameter and depth in accordance with manufacturer’s printed installation instructions (MPII)

X

P

X a. Anchors installed horizontally or upwardly inclined to support (by certified inspector)

X 4. Verify that adhesive material is in accordance with the

Contract Documents. Verify that the material is stored, missed, and injected in accordance with the manufacturer’s instructions

X

O

X a. Anchors installed horizontally or upwardly inclined to support (by certified inspector)

X 5. Verify anchors to be installed are clean, oil-free, and free of loose rust, paint, or other coatings X

P

X a. Anchors installed horizontally or upwardly inclined to support (by certified inspector)

X 6. Verify that installed adhesive anchors are securely fixed in place to prevent displacement while the adhesive cures.

Unless otherwise shown on the contract drawings, anchors should be installed perpendicular to the concrete surface.

Anchors displaced before full adhesive cure shall be considered damaged and replaced at the Contractor’s expense. Installed reinforcing bars/threaded bars shall not be bent after being adhesively embedded in hardened, sound concrete, unless permitted by the RDP.

X

P

X a. Anchors installed horizontally or upwardly inclined to support (by certified inspector)

X 7. Verify that the anchor materials, length, diameters, embedment, and finishes are in accordance with the

Contract Documents

X 8. Adhesive anchors shall be tension proof loaded to loads indicated in the contract documents for a specific anchor type. Proof loading shall be performed after a minimum curing period specified by the manufacturer. Anchors shall have no visible indications of displacement or damage during or after proof load application. Concrete cracking in the vicinity of the anchor after loading shall be considered a failure.

X 9. If more than 5% of the tested adhesive anchors fail to achieve the specified proof load within the limits defined on the contract documents, 5% of the anchors of the same diameter and type as the failed anchor shall be proof tested, unless otherwise directed by the RDP.