Excavations and Backfilling Works Notes

Specifications for Excavations and Backfilling Works

  • General Overview:

    • The document provides guidelines for excavations and backfilling works based on standard specifications from the Ministry of Public Works and Housing (1996).

    • Includes civil, architectural, mechanical, and electrical works.

    • The Bill of Quantities (BOQ) outlines standard quantities for these works.

  • General Specifications:

    • Specified works include site cleaning prior to excavation, rubbish removal, and removal of unwanted trees.

    • The site must be free of obstacles to ensure smooth operations.

  • Bill of Quantities (BOQ) Details:

    • Excavation work prices must include removal of buried structures and surplus material.

    • Quantities must be based on elements' dimensions specified in drawings.

    • Specific types of soil (clean sand or kurkar) must be used for backfilling, with compaction tests conducted.

Excavation Parameters

  • Types of Soil:

    • Excavation can include various soil types as specified in drawings, e.g.

    • 1.1 Excavation of any soil type in cubic meters (M³) with required works.

    • 1.2 Backfilling approved excavated material to maintain levels.

    • 1.3 Use of imported clean sand material for backfilling (M³).

  • Filling Requirements:

    • Filling operations must only commence after obtaining written permission from the engineer.

    • Materials must be free of rubbish and organic substances.

    • Each filling layer must not exceed 25 cm, and proper compaction must be ensured.

Related Issues

  1. Rocks and Solid Ground Layers:

    • Specialized tools should be employed for accuracy and safety.

    • Activities may need engineer approval if blasting is involved.

  2. Agricultural Soil:

    • Contractor may have to handle agricultural layers and keep them for landscaping purposes at no extra cost.

  3. Site Leveling:

    • Essential for preparing foundations and should not incur extra costs.

Site Management

  • Safety Precautions:

    • Regular checks of excavation sites for stability.

    • Ensure safe access and means to prevent collapse.

  • Excavation Safety Key Points:

    • Avoid underground utilities and ensure safe digging practices.

    • Check excavation stability daily before work.

Excavation Equipment

  • Hand Tools:

    • Spade, shovel, hoe, trowel, rake, pickaxe, mattock for smaller depths.

  • Machinery Tools:

    • Tracked and wheeled excavators, bulldozers, chain trenchers for larger depths.

    • Equipment includes dragline excavators, front-end loaders, and dump trucks.

Safety Procedures

  • Contractor’s responsibility includes securing the site from collapses and handling damages to adjacent structures.

  • Contractors must correct any damages caused without financial compensation from the employer.

Quantity Surveying

  • All excavation quantities calculated based on proper principles.

  • Volumes calculated from planned areas and vertical heights from excavation bases.

This document serves as a comprehensive guide on the processes, responsibilities, and specifications related to excavations and backfilling works ensuring that all parties adhere to standards while managing site activities effectively.