We believe that a quality work begins at the base. In our trajectory, begun in 1979, we provide consulting services in foundations and earthworks, geotechnical and geo-environmental investigations, geotechnical instrumentation and soil laboratory tests.

Damasco Penna

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24/09/2017(Português do Brasil) Prática de fundações e geotecnia – Pós graduação FESP

Services


  • PIEZOCONE TESTS (CPTU)
  • DILATOMETRIC TESTS (DMT)
  • VANE TESTS
  • PRESSUREMETER TESTS (PMT)
  • ROTARY DRILLING
  • SAMPLE COLLECTION
  • SPT SOUNDINGS
  • ENVIRONMENTAL INVESTIGATIONS
  • LABORATORY TESTS

PIEZOCONE TESTS (CPTU)
 

CPT-u (Cone Penetration Testing) is an in-situ test used to obtain data on several soil aspects. Well known worldwide as one of the most traditional and precise geotechnical investigation tool, it enables determining foundation dimensions and estimating settlement rates, among other operations.

While the cone is being driven down, its sensors make three readings at each centimeter:

  • Tip resistance (qc)
  • Sleeve friction (fs) (fs)
  • Pore pressure (u2))

The information is transmitted to the surface in real time and processed by computer.

Excess pore water pressure are read by means of a porous element situated at the base of the cone and saturated with silicone oil by vacuum pump. When needed, it is also possible to perform pore pressure dissipation testing during the test.

In addition to the data read in real time during the test (qc, fs and u2), the following properties can also be obtained through correlations:

  • Stratigraphy;
  • Geotechnical profile (Soil behavior);
  • Consolidation coefficient (Ch and Cv);
  • Relative density (Dr);
  • Undrained shear strenght (Su);
  • Effective friction angle of sands (Ø);
  • Stress history (preconsolidation stress, OCR);
  • Permeability coefficient (K).

ensaio-cptu
Piezocone equipment


Saturation vacuum pump




DILATOMETRIC TESTS (DMT and SDMT)

 

Used worldwide since 1975, DMT (Dilatometric Marchetti Test) is one of the most precise tools for in situ testing to determine settling and estimate the elasticity module (E) of prospected soil layers. Quick and simple to perform and applicable to almost any kind of soil, the test is regulated bylo Eurocode 7 and ASTM D6635 – 01(2007) Standard Test Method for Performing the Flat Plate Dilatometer.

 

The DMT test consists in a stainless steel blade with a thin circular expandable pushed into the ground. At every 0,2m pressure is applied to inflate the membrane. Electrical sensors provide the measures “A” and “B”.

 

The dilatometer blade can be advanced using a conventional CPT pusher and being an “in-situ” test, can obtain measures at several places in the same site and in different depths.

 

 
VANE TESTS
 
The Vane Test is a traditional method of determining the shear strength of saturated soft clay, submitted to undrained loading conditions (Su).
 
O Ensaio
Standardized by Brazilian ABNT NBR 10905/89 and ASTM D2573-08 Standard test method for field vane sher test in cohesive soil, the test uses a standard size steel vane with a cross-section shaped like a cross. The test consists of driving the vane statically into the soil until reaching the desired position to perform the test.
 
The vane is driven down using a double rod system to eliminate any friction between the vane rod and the soil and any interference in measuring shear strength.
 
Once the vane is in place, torque is applied to the blade by a measurement unit at a speed of 0.1 to 0.2 degrees per second. Maximum torque makes it possible to obtain the undrained shear strength value under natural unstrained soil conditions.
 

vane-tests-equipamento-300x200

 
 
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Afterwards, the undrained shear strength – representing a post-disturbance clay state – is determined by quickly rotating the vane 10 times consecutively to obtain the undrained strength of the soil under disturbed conditions.
 
Damasco Penna uses type “A” equipment that guarantees results and precise readings in electronically controlled tests performed without previous boring.
 

 
Results
The following results can be obtained by Vane Testing:

  • Torque graph according to rotation
  • Undrained strength
  • Disturbed undrained strength
  • Clay structure sensitivity

vane-test-resultado2-300x275-1

 

 
PRESSUREMETER TESTS (PMT)
 
Developed in France in the 1950s by engineer Louis Ménard, the Ménard-type pressuremeter tests (PMT) consist of inserting a pressuremeter probe into a borehole and then applying nitrogen gas to deform a flexible membrane.
Deformation measurements are read by a control panel that measures pressure and volume variations occurring as a result of soil deformation.
 
A strain x strain curve of the prospected soil is obtained, providing the following information:

  • Ménard pressiometric module
  • Ménard limit pressure;
  • Residual pressure.

These results allow us to evaluate the following parameters through correlations:

  • Soil modulus (E);
  • Undrained resistance of saturated clayey soils (Su);
  • Drained resistance of sandy soils (ø);
  • Load capacity and rebounding in deep and shallow foundations

dsc_5124-300x199

 
 
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The tests are performed in accordance to ASTM D4719 –Standard Test Method for Prebored Pressuremeter Testing in Soils and Eurocode 7.
ensaio-pressiometro

 
ROTARY DRILLING
 
DAMASCO PENNA has state-of-the-art drill rigs, mounted on treadmills or tires, and can work on hard to reach sites, ensuring greater agility in the mobilization between points beyond safety to operators.
 
Drilling Methods
Depending on the purpose of drilling and desired the sample diameter, traditional methods can be used, as well as “wire-line” method.
 
Results presentation
The log results are presented in individual profiles containing the description and classification of the soil, SPT resistance index, water table level and recovery percentage and RQD index as well as a photographic report as illustrated below.
 

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Rock coring samples

 
 
1055
CME-550 Drilling Rig
 
 

 

SAMPLE COLLECTION
Soil sampling possibilities are diverse and depend on the purpose of analysis, soil type, depth, strength, among other variables.

Over the years, we acquired technical ability to obtain various types of samples which can be collected manually mechanically..

Above we describe some of the main ways of obtaining soil samples for laboratory testing.

 
SHELBY SAMPLER
Used to collect undisturbed fine soil samples (clays and silty clays) of low consistency, the “Shelby” samplers are performed
The technique used consists of mechanized drilling with hollow auger castings, with internal rods that prevent the entry of soil in the trenches during drilling.
When the quota is reached, the Shelby sampler is inserted and by means of static crimping the collection is performed.
The use of the cast cores allows high quality collections even at greater depths.

 
DENISON SAMPLER
Denison Samplers are used to collect undisturbed samples with the rotary drilling rigs, especially in stiff and compact soils
where other sampling techniques would not work.

This sampler consists in a triple barrel fitted externally to a cutting shoe. An external sleeve is driven into the ground by rotating and inserting water.The sample is collected inside this tube and extracted afterwards in the soil laboratory.
 
“CONTINUOUS CUTTING” SAMPLER
Developed by Damasco Penna, in order to collect “nearly undisturbed” soil samples in compacted landfills, the “continuous cutting” sampler has thick wall and is driven dynamically into the ground with a pneumatic hammer.

The samples are collected with 3-inch diameter PVC inner tubes and after collected the samples are sealed with wax to maintain its natural moisture. After, in the soil laboratory tests such as mini-Proctor, hydrostatic balance and natural moisture content, can be performed, allowing determination of the compaction degree of deep landfills soil layers.

The collections can be carried out at great depths, making it possible to test different layers and inaccessible to the verification wells.

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corte-continuo-recortado_horizontal

 

 
SPT SOUNDINGS
 
Percussion Drilling (SPT-T) is currently the most traditional form of geotechnical research in Brazil, being performed by hundreds of companies throughout the country. Standardized by the ABNT NBR-6484 standard, which is being revised, it allows soil samples, resistance measurement (SPT), groundwater reading, and the possibility of reading the torque during the test.
 
Mechanical soundings
Following the trend of other countries as well as meeting the national demands of specific customers, the Damascus Penna has equipment that performs this test mechanically, with automatic hammer of SPT and drilling by means of cast helical blocks. This process ensures greater accuracy, productivity gains, improved operator safety and water-less drilling, enabling accurate reading of the water table level.

 

 
 
amostras-spt
SPT sampling samples

 

 
 
ENVIRONMENTAL INVESTIGATIONS
 
The geo-environmental investigations allows the determination of contaminants in soil and groundwater. Since 2007 , our company have been providing services such as installation of monitoring wells , soil sampling for environmental purposes , groundwater collection , among others.
 
This type of work requires use of tools and properly cleaned and decontaminated equipment , ensuring sampling reliability as well as avoiding any cross-contamination.
 
We provide our customers drill rigs able to install monitoring wells with more than 100m deep in soil and rock , as well as “direct push” soil sampling in various types of plants and geological formations.
 
sondagens-ambientais-1
Geo-environmental investigations with Geoprobe 6625CPT equipment

 
LABORATORY TESTS
 
The company has a field laboratory service in operation since 1980 to keep technological control of earthwork projects and soil characterization with tests such as:
 

  • Water content
  • Bulk density
  • Liquid limit anda plastic limit
  • Grain size analysis (sieve analysis and sedimentation annalysis)
  • Specific gravity of soil particles
  • Standard Proctor compaction
  • Modified Proctor compaction
  • California Bearing Ratio

caminhoes
 

 

Geotechnical Consulting

Damasco Penna, Inc. provides site investigation and foundations consultancy services for diverse industry sectors

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Health and Safety

With more than 5,000 projects carried out (buildings, industries, hypermarkets, mall and works of art) we have a specialized team of geotechnical engineers

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Videos

CPTU / Piezocone Tests
Soil Sampling DT-22 Geoprobe
Piezocone Tests (CPTU)
Dilatometric Testing (DMT)
Mechanized SPT polls
Rotary drilling and mechanized SPT
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Contact

SÃO PAULO

Alameda Rio Negro, 1105 – 1º andar – cj. 11
Alphaville – SP – Brasil
Phone: +55 11 4195-8385 damasco@damascopenna.com.br