DIRECT PENETRATION & CORE BORING Flashcards
(24 cards)
A method of geotechnical investigation that physically samples and tests soil, rocks, and groundwater to analyze underground conditions.
Direct Penetration
Determines soil strength, density, and composition.
Helps in designing stable foundations for buildings and infrastructure.
Essential for assessing soil suitability for construction.
Direct Penetration
Inclusion in Direct Penetration
TRENCHING
PITTING
is a pit that is elongated over some distance in order to establish how the Surface conditions change over various parts of the work.
Trenching
pits are dug either manually or with an excavator in order to reveal the subsurface conditions to the depth desired.
Pitting test
2 TYPES OF DIRECT PENETRATION TESTS
1.Standard Penetration Test (SPT)
2.Cone Penetration Test (CPT)
Measures soil resistance using a hammer-driven sampler.
Purpose: Determines relative density and shearing resistance of cohesionless soils and strength of stiff cohesive soils.
Standard Penetration Test (SPT)
✔Used for sands, silts, clays, and weathered rocks.
✔ Common in foundation analysis for buildings, bridges, and
roads.
✔ Provides an approximate guide to soil properties but is
cost-effective and widely used.
Standard Penetration Test (SPT)
- is a common in site testing method used to determine the geotechnical engineering properties of soils and assessing subsurface stratigraphy. The test is also caled, Dutch Cone test.
Purpose: Determines soil type, strength, and layering without disturbing the ground significantly.
Cone Penetration Test (CPT)
✔ No borehole required—fast and cost-efficient.
✔ Provides continuous soil profile readings.
✔ Best for soft clays, silts, and sands where sampling is
difficult.
Cone Penetration Test (CPT)
A drilling method that extracts cylindrical cores of rock or soil for analysis.
Purpose:
Evaluates subsurface geology.
Identifies rock formations and ground conditions.
Essential for foundation design, tunneling, and mining exploration.
Core Boring
A hollow cylindrical drill made of metal with diamond or carbide tips for cutting through surfaces.
Core Drill:
cutting process that uses a drill bit to cut/enlarge a hole of circular cross-section in solid material
Drilling
Scaling, leaching, or pattern cracking can be signs of the need for ______
core drilling
Four Methods of Drilling
- PERCUSSION DRILLING
- CHURN DRILLING
- DIAMOND CORE
- JET DRILLING
It consists basically of a hammer unit which is driven by compressed air. This hammer unit imparts a series of short, rapid, blows to the drill steel or rods and at the same time slowly rotates them. Mainly used for water well drilling and not commonly used in mineral expo.
Percussion Drilling
It is a drilling technique in which a sharpened steel bit attached to rope or cable is repeatedlyraised and lowered at the rate of 30-60 strokes/min and crushing the rock and making the hole deeper. Useful in exploration work for sampling soft formations up to a depth of 100-150 m.
Churn Drilling
Designed specifically for mineral exploration and is the most important type of drilling. Recovery of the core drill enables details of the geology, ground conditions and mineralogy to be obtained that is no possible with any other method.
Diamond Core
Two Types of Diamond Drilling:
CONVENTIONAL DRILLING
WIRE LINE DRILLING
It is a placer sampling method where a casing and chisel-pointed bit are advanced by percussion while water is forced ahead to loosen the material and to flush out and bring the sample to the surface. It is replacing churn drilling in many placer mining districts where minerals other than gold are involved.
Jet Drilling
2 JET DRILLING
✓ Auger drills
✓ Rotary Drills
Excavation or fills for any building structure and excavations or fills accessory thereto shall be so constructed or protected that they do not endanger life and property.
PD. 1096 National Building Code of the Philippines Section 08.01 Article 2 Paragraph B.
They are important in soil sampling, beach placer sampling, and in evaluating clay deposits. In any event, auger drilling stops at the first boulder.
✓ Auger drills
It is mostly used to drill big holes in large quarries, open pit mines, petroleum extraction, and other fields.
✓ Rotary Drills
