Geotechnical Engineering Investigation


PT. BSG serves Geotechnical Engineering Investigation, includes:

  • Soil / Rock Core Drilling and Sampling
  • Standard Penetration Test (SPT)
  • Cone Penetration Test (CPT)
  • Soil / Rock Mechanical Reporting
  • Insitu Permeability Test (Packer Test Constant Head / Falling Head)

Cone Peneration Test (CPT)

The standardized cone – penetrometer test (CPT) involves pushing a 3.58 cm diameter 60o cone through the underlying ground at a rate 1-2 cm/s. the CPT can be very effective in site characterization, especially site with discrete stratigraphic horizons or discontinuous lenses. The methodology was adopted by ASTM D 3441. the CPT is a valuable method of assessing subsurface stratigraphy associated with soft materials, discontinous lenses, organic materials (peats), potentially liquefiable materials (silt and sands), and landslides. CPT can be easily and quickly mobilize to site and relatively quick simple and economical. The main disadvantages are not obtaining a soil sample for viasual/laboratory inspection, and sometimes serveral limited depth capanility.

Quantity : 4 unit Capacity : 2.5 tonf


The piezecone test (CPTu) includes the measurement of tip resistance, side friction and excess dynamic pore water pressure. These pore water pressures are developed during the steady, slow penetration of the cone into the soil.Application of CPTu tests may not be possible when coarse and very coarse fraction (sand-gravel mix, gravel, rock waste, clayey weathering waste) are occurring in the subsoil. CPTu tests should always be supplemented by research drillings, soil sampling and laboratory tests.

Drilling machines

PT. BSG have 5 unit imported drilling machines for soil/rock drilling and sampling with maximum 100 m depth.YBMYSO 01,YBMYSO 05,Toho,Yamaguchi in good performance will be running for service our client. Drilling machines use for obtaining a soil sample for visual/laboratory inspection and supporting Standard PenetrationTest(SPT)orothertest.

Downhole Seismic Testing

Downhole seismic testing is one field test that is commonly used to determine compression-wave (P) and shearwave (S) velocity profiles in geotechnical earthquake engineering investigations. These profiles are required input in evaluations of the responses to earthquake shaking of geotechnical sites and structures at these sites. This technique measures vertical changes in seismic velocity by placing a source at the top of a borehole and measuring travel-times at multiple intervals in the borehole, usually with a 3-component geophone.The preferred method for preparing a borehole for downhole testing incorporates one borehole.A dry test hole is preferred to avoid signal noise caused by waves transmitted through the water column in a water-filled test hole. The methodology was adopted from ASTM D4700. Common applications include Bridge/dam foundation analysis, Insitu materials testing, Soil and rock mechanics, Earthquake engineering, Liquefaction analysis.

Dilatometer (DMT)

The Marchetti dilatometer (DMT) consists of a flat steel blade having a thin, expandable, circular steel membrane mounted on its surface. The blade is connected to the control-measurement unit by pneumatic wire used to transfer gas pressure exerted on the membrane. The test involves pressing of the blade which membrane deforms under the influence of the acting gas pressure in the ground.Dilatometer can be used to identify the type and state of the soil, determine the geological profile and history of the stress condition, estimate values of the geotechnical parameters (undrained shear strength, coefficient of the at-rest earth pressure of the non-cohesive and cohesive soils, overconsolidation stress, deformation modules). Based on the in situ measurements of the values of pressure and the estimated values of the effective vertical stress and pore pressure, the following dilatometric parameters of the subsoil are determined (at the depth of the measurement)


Pile Driving Analyzer (PDA) is one type of dynamic test using the wave analysis method which can be performed during or after pile installation using conventional pile driving equipment. This test can be applied to driven steel, driven timber and even concrete piles (eg. pre-stressed driven concrete piles, drilled shafts, auger cast piles). PDA equipment calculates the velocity and force signals obtained from accelerometers and strain transducers attached to the pile during driving. This data is analyzed using CAPWAP software to calculate the pile capacity.The information that PDA testing can provide includes: verification of pile capacity at the time of testing, data for developing termination criteria for design loads, assessment of energy transfer and driving efficiency, measurement of stress levels induced on the pile during driving, and assessment of pile integrity and possible damage.The ideal hammer weight / mass for testing PDA test is 1% - 2% of the pile foundation capacity required to achieve. The number of pile foundations used with PDA test is generally as much as 1% of the number of pile foundation points in a single project. (SNI Geotechnical Engineering 8460 – 2017)


Instrumentation of geotechnical structure in the field has been beneficial in evaluating the movements and failure in the structure under real condition. As well as assessing the performance of new materials and methods used in the design and construction of geostructures.