Matakuliah: S2094 / Rekayasa Pondasi

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Pertemuan 04Penyelidikan Tanah

• Matakuliah S2094 / Rekayasa Pondasi
• Tahun 2005
• Versi 1.1

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Cone Penetration Test (CPT)

• Originally Developed in Netherlands 1930s
• Further developments in 1950s
• Dutch Cone
• ASTM D 3441
• Types of CPT devices
• mechanical cone
• electric cone
• piezocone

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Mechanical Cone
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Electrical Cone
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Cone Penetrometer
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CPT Truck
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Crawler Type CPT Truck
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CPT Truck Interior
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CPT Operation Inside the CPT Truck
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CPT Data Acquisition Analysis
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Cone Penetration Test (Sondir)
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Cone Penetration Test (Sondir)
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Cone Penetration Test (Sondir)
cu qc/14 (Begeman1963)cu fs/12qc/N 3-6
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Cone Penetration Test (Sondir)

• Ada 2 macam yaitu
• Standard type (mantel konus)
• Friction Sleeve (bikonus)
• Ujungnya terdiri dari sebuah kerucut (konus) 600,
  luas penampang 10 cm2.
• Dapat mencapai kedalaman 30 m, tergantung kondisi
  tanah.
• Sondir ringan 2.5 ton Sondir berat 10 ton
• Cocok untuk di Indonesia, terdapat banyak lapisan
  lempung yang dalam dengan kekuatan rendah.
• Nilai konus dalam kg/cm2
• Nilai konus yang diperoleh sondir tidak dapat
  disamakan dengan daya dukung tanah !!

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Cone Penetration Test (CPT)

• Measures
• Cone Resistance, qc
• Sleeve Resistance, fsc
• Typical CPT results

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Typical CPT Data
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Use of CPT Data
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CPT Versus SPT

• CPT Advantages over SPT
• provides much better resolution, reliability
• versatility pore water pressure, dynamic soil
  properties
• CPT Disadvantages
• Does not give a sample
• Will not work with soil with gravel
• Need to mobilize a special rig

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Vane Shear Test

• Originally developed by Swedisg Engineer, John
  Olsson in 1920s
• Now Standardized as ASTM D2573
• Specially suited for soft, sensitive clays
• Quick test, used to determine undrained shear
  strength

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Vane Shear Test

• Relationship between Su and applied Torque

• Relationship between Su and applied Torque (after
  correction factor)

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Pressuremeter
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Flat Plate Dilatometer
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Comparison of In-Situ Test Methods

• Table 3.5
• Simplicity ruggedness
• Ease of Testing
• Resolution
• Basis for Interpretation
• Types of Soils
• Equipment Availability
• Potential for Future Development

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Comparison of In-Situ Test Methods
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Geophysical Exploration Methods

• Seismic Survey
• Seismic Refraction
• Seismic Reflection
• Electrical Resistivity
• Ground Penetration Radar

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• Seismic Survey
• Seismic Refraction

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• Seismic Survey
• Seismic Reflection

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• Electrical Resistivity
• Ground Penetration Radar

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Economics