Soils/Soil Investigation

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Soil investigation is to carry out physical testing on site to understand the ground conditions for geotechnical design (foundations, retaining walls & soil improvement). Site works are usually comprising of Standard Penetration Test, [1]Cone Penetration Test[2], Vane Shear Test[3], Installation of Water Standpipe, Instrumentations, ... etc. Usually, laboratory testing on soil samples extracted from site works will be carried out to determine the engineering properties of soil.

Soil moisture

Soil moisture is water in the soil that affects soil conditions. The type and amount of soil moisture must be considered on the design and construction of a foundation. If water collects in an enclosed space, such as te area beneath the floor of a residential crawl space foundation, it can cause odor, mold, and wood decay. Water penetrating the walls of a full basment xan make the basement area unsuitable as a storage, work, or living space. methods commonly used to prevent potential surface and ground water problems include proper grading around the perimeter of the building, drain tile ,and vapor barriers.

Soil compaction

Compact soil.jpg

Soil compaction is the process of apply energy to loose soil to increase its density and load-bearing capacity through consolidation and removal of voids Soil compaction is commonly specified for building foundations,trench backfills,curbs and gutter, bridge supports, slab work, driveways,sidewalks, cemeteries and other confined work areas.

During excavating, grading , and /or trench, air infiltrating the soil causes air void and an increase in volume. Air voids in the soil cause weakness and inability to carry heavy loads. Air voids in uncompacted soil also cause undesirable settlement of a structure, resulting in cracks or complete failure. Compacted soil reduces water penetration and related problems.Water penetration swells the soil during the wet season. Water removal contracts the soil during the dry season. In addition, water expands when frozen in the soil, causing heaving and cracking of walls and floor slabs.

Soil compaction methods

Soil compaction methods include impact force, vibration, and static force. Impact force compaction using a machine that alternately strike and leaves the ground at high speed to increase soil density. Vibration compaction is compaction using a a machine to apply high-frequency vibration to the soil to increase soil density. Static force compaction is compaction using heavy machine that squeezes soil particles together without vibratory motion to increase soil density.

  1. "Standard penetration test". Wikipedia. 2021-10-11. 
  2. "Cone penetration test". Wikipedia. 2021-01-13. 
  3. "Shear vane test". Wikipedia. 2019-12-05.