HIGHWAY QUALITY TEST

Method Statement for Open Foundation

1. Description

This Method Statement covers the construction of Plain Cement Concrete (PCC) and Reinforced Cement Concrete (RCC) Open Foundations in accordance with the approved drawings, contract specifications, and the MoRTH Specifications for Road and Bridge Works.

The scope of work includes survey and setting out, excavation, preparation of the foundation bed, dewatering (where required), laying of PCC, reinforcement fixing, formwork, concreting, curing, quality control, safety requirements, and backfilling after completion of foundation works.

2. Materials

All materials used for the construction of the open foundation shall conform to Section 1000 of the MoRTH Specifications, relevant Indian Standards (IS Codes), approved mix designs, and the requirements of the Contract.

Only approved materials accompanied by valid test certificates and accepted by the Engineer shall be used for the work. Materials shall be properly stored, handled, and protected from contamination or deterioration prior to use.

• Cement conforming to the relevant IS Specifications.
• Fine Aggregate conforming to IS 383 and MoRTH requirements.
• Coarse Aggregate conforming to IS 383 and MoRTH requirements.
• Reinforcement Steel conforming to IS 1786 and approved Bar Bending Schedule (BBS).
• Water suitable for concrete production and curing in accordance with IS 456.
• Approved chemical admixtures, if specified in the approved mix design.
• Formwork materials capable of maintaining the required line, level, dimensions, and finish.

3. Preparation of Foundations

Excavation for laying the foundation shall be carried out in accordance with MoRTH Clause 300 and the approved drawings. The excavation shall be taken to the required line, level, dimensions, and founding level specified in the drawings.

Open foundations shall preferably be constructed under dry conditions. Where groundwater or seepage is encountered, suitable dewatering arrangements such as pumping, well-point systems, or diversion channels shall be provided and maintained throughout the construction period to ensure a clean, stable, and workable foundation bed.

The excavation bed shall be cleaned of all loose, soft, organic, and unsuitable materials before inspection by the Engineer. No concrete shall be placed until the foundation bed has been inspected and approved.

4. Setting Out

The foundation layout shall be established in accordance with the approved General Arrangement (GA) drawings and survey control points.

The plan dimensions of the foundation shall be set out at the bottom of the excavation using a Total Station, Auto Level, and measuring tape. The layout shall be checked with respect to the original centre line, reference benchmarks, and structural axes to ensure dimensional accuracy.

It shall be ensured that no portion of the bearing surface is higher than the approved founding level indicated on the drawings. All survey checks shall be verified and approved by the Engineer before commencement of PCC works.

5. Safe Bearing Capacity (SBC) of Soil

The Safe Bearing Capacity (SBC) of the foundation soil shall be verified at the founding level in accordance with the approved drawings, geotechnical investigation report, and project specifications.

Where specified in the Contract, the SBC shall be confirmed by the in-house Quality Control (QC) Laboratory or an approved testing agency before commencement of foundation works. Test results shall be reviewed and approved by the Engineer prior to placing Plain Cement Concrete (PCC).

If the actual soil conditions or Safe Bearing Capacity are found to differ from the design assumptions, the matter shall be immediately reported to the Engineer for further investigation and approval before proceeding with the work.

6. Construction of Open Foundation

Construction of the open foundation shall be carried out in accordance with the approved drawings, relevant MoRTH Specifications, and the approved Method Statement. The foundation bed shall be inspected and approved by the Engineer before commencement of concrete works.

Where the bearing surface consists of natural earth, a 150 mm thick Plain Cement Concrete (PCC) layer of Grade M15 shall be laid below the structural foundation concrete unless otherwise specified in the drawings or Contract. The lean concrete shall provide a clean, level, and stable working surface for reinforcement fixing and formwork erection.

Generally, no side formwork is required for the lean concrete layer. However, where necessary to maintain dimensions or due to unstable excavation sides, suitable formwork may be provided with the approval of the Engineer.

Side formwork shall be provided for the structural foundation concrete to maintain the required dimensions, alignment, and surface finish. Top formwork shall also be provided where the slope of the concrete surface is steeper than 1 Vertical : 3 Horizontal (1V:3H) to prevent displacement or slippage of freshly placed concrete.

Where concrete is placed on sloping surfaces without top formwork, the concrete slump shall be carefully controlled to ensure adequate workability while preventing segregation or movement of fresh concrete. The concrete shall be placed in a continuous operation and compacted using approved mechanical vibrators.

In cases involving steeply sloping surfaces, the top formwork may be erected progressively as concreting advances to ensure proper compaction and dimensional accuracy.

Reinforcement shall be fabricated, fixed, and supported strictly in accordance with the approved structural drawings, Bar Bending Schedule (BBS), IRC:112, and MoRTH Specifications. The specified clear cover shall be maintained throughout the concreting operation using approved concrete cover blocks.

Before placing the lean concrete, the foundation bed shall be thoroughly cleaned of all loose soil, organic matter, standing water, and other deleterious materials. The surface shall be lightly moistened to prevent excessive absorption of water from the concrete. Care shall be taken to avoid muddy conditions. Any softened or disturbed portion of the foundation bed resulting from over-wetting or other causes shall be removed, re-compacted where necessary, and brought back to the required level before concrete placement.

7. Inspection Plan and Testing

8. Safety Measures

All construction activities shall be carried out in accordance with the approved Environment, Health & Safety (EHS) Plan, applicable statutory regulations, and project safety requirements.

• Ensure all personnel wear mandatory Personal Protective Equipment (PPE), including Safety Helmet, Reflective Jacket, Safety Shoes, Gloves, and Eye Protection.
• Provide adequate barricading, warning signs, safety cones, caution tapes, and traffic management arrangements around the work area.
• Ensure safe access, working platforms, ladders, and walkways for inspection and construction activities.
• Protect excavations against collapse by providing safe side slopes, shoring, or bracing wherever required.
• Maintain proper dewatering arrangements to prevent flooding and unsafe working conditions.
• Use only certified lifting equipment operated by trained personnel.
• Ensure all electrical equipment is properly earthed and periodically inspected.
• Provide adequate illumination for night-time construction activities.
• Keep first-aid boxes, fire extinguishers, and emergency contact information readily available at the work site.
• Conduct daily toolbox talks and safety briefings before commencement of work.
• Maintain good housekeeping to eliminate trip hazards and ensure a safe working environment.