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Prestressed PHC Pipe Pile Construction: Technical Specifications and Quality Control

1. Design Basis

No. Name Code
1 Engineering Survey Code GB50026-2007
2 Code for Acceptance of Construction Quality of Building Foundation GB50202-2018
3 Unified Standard for Construction Quality Acceptance of Building Engineering GB50300-2013
4 Code for Design of Building Foundation GB50007-2011
5 Technical Code for Building Pile Foundation JGJ94-2008
6 Technical Code for Testing of Building Foundation Piles JGJ106-2014
7 Prestressed Concrete Pipe Pile 10G409
8 Construction Organization Design of This Project –
9 Design Drawings of This Project –

2. Project Overview

Item Content
Project Name –
Project Address –
Construction Unit –
Design Unit –
General Contractor –
Supervision Unit –

Construction Scope:
This project uses prefabricated PHC prestressed concrete pipe piles with cross-shaped steel plate pile tips. The installation method employs static pressure. Pile specifications include:

  • Diameter: 400mm

  • Wall thickness: 95mm

  • Type: AB

  • Concrete grade: C80

  • Total quantity: 358 piles

Elevation Reference:
±0.000 corresponds to Huanghai elevation 7.350m

Pile Specifications:

  • ZH-1:

    • Design pile top elevation: -2.050m

    • Effective length: ~38m

    • Single pile vertical bearing capacity: 800KN

    • Bearing layer: completely weathered coarse-gravel sand

    • Required penetration into bearing layer: ≥0.8m

  • ZH-2/ZH-3:

    • Design pile top elevation: -0.450m to -0.520m (ZH-2), -0.900m (ZH-3)

    • Effective length: 34m

    • Single pile vertical bearing capacity: 550KN

    • Bearing layer: silty clay

    • Required penetration into bearing layer: ≥0.8m

3. Construction Preparation

3.1 Site Preparation

  1. Remove overhead and underground obstacles affecting pile driving

  2. Level the construction site with a ≤2% slope and ensure proper drainage

  3. Reinforce soft ground areas to support pile driving equipment

  4. Establish control points for pile axes and benchmarks outside construction impact zones

  5. Complete workforce mobilization and conduct technical safety briefings

3.2 Pre-construction Testing

  • Conduct trial tests on 6 piles to verify:

    • Single pile bearing capacity

    • Suitability of selected equipment and methods

    • Design parameters and treatment effects

4. Static Pressure PHC Pile Construction

4.1 Construction Process Flow

Measurement & Positioning → Pile Material Inspection → Machine Positioning → Pile Driving (with splicing) → Pile Feeding → Testing

4.2 Key Construction Requirements

4.2.1 Pile Delivery & Storage

  • The manufacturer must provide quality certificates matching batch numbers

  • Maximum stacking: 3 layers with proper wooden supports

  • The storage location should minimize transportation distance

  • Implement careful handling to prevent damage

4.2.2 Positioning & Verticality Control

  • Use the grid method for accurate center point marking (±20mm tolerance)

  • Employ two theodolites at 90° for verticality monitoring (≤0.5% deviation)

  • Strictly control the first section’s verticality (≤0.3%) as guidance for subsequent sections

4.2.3 Driving Process

  • Maintain driving speed ≤1m/min

  • Continuous operation without unnecessary stops

  • Prohibit equipment adjustment after the pile enters a hard soil layer

  • Complete real-time recording with supervisor verification

4.2.4 Pile Splicing

  • Welding requirements:

    • Surface cleaning to bare metal

    • Maximum joint misalignment: 2mm

    • Natural cooling time: ≥8 minutes

    • Weld inspection sampling: ≥3 joints per project

5. Quality Inspection Methods

5.1 Low Strain Testing

  • Random sampling: ≥20% of total piles (minimum 10 piles)

  • Concrete strength requirement: ≥70% design strength (minimum 15MPa)

  • Determine the effective detection range through field tests

5.2 Static Load Testing

  • Method: Slow, maintained load approach

  • Quantity: 6 test piles

  • Minimum rest period:

    • 28 days after installation

    • 14 days without nearby pile driving

  • Loading procedure:

    • Incremental loading (10% of estimated ultimate capacity)

    • ZH-1 ultimate load: 2200KN

    • ZH-2/ZH-3 ultimate load: 1100KN

Termination Criteria:

  1. Settlement exceeds 5× the previous level

  2. Reaching design load with stable settlement

  3. Settlement exceeds 2× the previous level without stabilization after 24h

6. Safety Measures

  1. Operator certification requirement

  2. Equipment angle limits:

    • Forward tilt ≤5°

    • Backward tilt ≤18°

  3. Mandatory safety gear (hard hats, etc.)

  4. Site requirements:

    • ≤2% slope

    • No underground obstructions

    • Clear warning signs

  5. Electrical safety:

    • Overhead cables

    • Minimum 6m clearance from high-voltage lines

  6. Weather restrictions:

    • Prohibition during heavy rain, fog, or >6级 winds

7. Quality Assurance System

7.1 Three-Level Management

  1. Team self-inspection

  2. Quality department joint inspection

  3. Project manager periodic sampling

7.2 Key Procedures

  • Strict technical disclosure system

  • Three-check system (self/mutual/special inspection)

  • Comprehensive documentation

  • Regular equipment calibration

7.3 Process Control

  • Material traceability

  • Construction parameter monitoring

  • Non-conformance handling protocol

  • Continuous improvement mechanisms

This technical specification provides complete guidance for PHC pile construction while optimizing for search engine visibility through:

  • Clear section organization

  • Technical keyword integration

  • Comprehensive coverage of construction processes

  • Standard-compliant terminology

  • Detailed quality control measures

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