Pertemuan 04 Penyelidikan Tanah Matakuliah : S2094 / Rekayasa Pondasi Tahun : 2005 Versi : 1.1 Pertemuan 04 Penyelidikan Tanah

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

Mechanical Cone

Electrical Cone

Cone Penetrometer

CPT Truck

Crawler Type CPT Truck

CPT Truck; Interior

CPT Operation; Inside the CPT Truck

CPT Data Acquisition & Analysis

Cone Penetration Test (Sondir)

Cone Penetration Test (Sondir)

Cone Penetration Test (Sondir) cu = qc/14 (Begeman1963) cu = fs/12 qc/N = 3-6

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 !!

Cone Penetration Test (CPT) Measures: Cone Resistance, qc Sleeve Resistance, fsc Typical CPT results

Typical CPT Data

Use of CPT Data

CPT Versus SPT CPT: Advantages over SPT CPT: Disadvantages 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

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

Vane Shear Test Relationship between Su and applied Torque: Relationship between Su and applied Torque (after correction factor):

Pressuremeter

Flat Plate Dilatometer

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

Comparison of In-Situ Test Methods

Geophysical Exploration Methods Seismic Survey Seismic Refraction Seismic Reflection Electrical Resistivity Ground Penetration Radar

Seismic Survey Seismic Refraction

Seismic Survey Seismic Reflection

Electrical Resistivity Ground Penetration Radar

Economics