Information-advertising booklet

Group of Service Companies
“MORINZHGEOLOGIA”
Member of the Russian Oil & Gas Builders Union
http://www.morinzhgeologia.ru/
METHODS AND EQUIPMENT FOR
ONSHORE GEOTECHNICAL INVESTIGATIONS
The Group of Service Companies “Morinzhgeologia” is a Member of the Russian Oil & Gas
Builders Union and is a partner of Non-Commercial Partnership “Central Association of
Organisations Executing Engineering Surveys for Construction” (NP “Centrizyskaniya”) and
has a Certificate of clearance for engineering-geological and geotechnical surveys.
It has been certified by the European Agency Lloyd`s Register Quality Assurance
for the compliance with the requirements of the international standard ISO9001:2008
“QUALITY MANAGEMENT SYSTEMS” and ISO14001:2004 “ENVIRONMENTAL
MANAGEMENT SYSTEMS”.
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The activities of “Morinzhgeologia” are predominantly associated with the execution of
geotechnical investigations in the Caspian Sea and onshore geotechnical investigations for the
construction of structures. We have carried out investigations for the construction of objects,
including the production facility of “LUKOIL-Nizhnevolzhskneft’” in Ilyinka Township.
More detailed information about “Morinzhgeologia” is contained in the Federal Reference
Book of the Fuel and Energy Complex of Russia for 2009.
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Onshore geotechnical investigations are carried out in accordance with the regulations and
technical requirements of the set of regulations SP 11-105-97 – “Geotechnical Surveys for
construction” of the State Committee of the Russian Federation for Construction,
incorporating both geotechnical and geophysical methods of investigations. The following
geotechnical methods are usually incorporated in the practice of geotechnical surveys:
•
Geodetic support of geotechnical operations.
•
Drilling of geotechnical boreholes.
•
Cone penetration testing of soils with measurements of pore pressure СРТu (Cone
penetration test with pore pressure-u);
•
Cone penetration testing of soils with measurements of pore pressure and seismic acoustic
channel SСРТu (Seismic CPTu);
•
Standard penetration testing of soils (SPT).
•
Vane testing of soils FVT (Field vane testing).
•
Determination of physical and mechanical properties of soils in situ using Pocket Vane
(PVane).
•
Determination of physical and mechanical properties of soils in situ using micropenetrometer (Pocket Penetrometer).
•
Laboratory investigations of soils aimed at the determination of their physical and
mechanical properties.
In complex geological conditions and for objects of the highest responsibility category,
geophysical methods are used, such as seismic acoustic surveys, electrometry etc.
Based on the clients’ demands, geotechnical investigations could incorporate any other
methods.
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METHODS AND EQUIPMENT FOR
ONSHORE GEOTECHNICAL INVESTIGATIONS
Geodetic support of geotechnical operations
The positioning of the locations of geotechnical operations is executed by a highly accurate
satellite system with the reception of differential corrections from a geostationary satellite. The
accuracy of positioning is within 1 cm.
High-performance GPS receiver ProMark2
ProMark2 combines the properties of a
geodetic receiver, executing measurements in
the post-processing mode, and those of a
receiver used for the reconnaissance or
autonomous navigation using signals from
geostationary satellite systems WAAS (Wide
Area Augmentation System) and EGNOS
(European Geostationary Navigation Overlay
Service). ProMark2 is an excellent instrument
for the execution of geodetic operations by one
operator.
The operator may choose either the mode of geodetic operations or the navigation mode. In the
latter case, ProMark2 ensures the accuracy of 3-5 metres in the autonomous mode, which is
achieved by the utilisation of the latest technologies and reception of the WAAS and EGNOS
corrections.
The navigation mode ensures the performance of two important tasks: reaching the location of
operations and reconnaissance of geodetic reference points. The operator enters the co-ordinates,
and ProMark2 leads him to the planned location of operations or the necessary reference point.
.
Using an external aerial and the Ashtech Solution post-processing software, ProMark2 allows to
determine or redetermine geodetic reference points with the accuracy 5 mm + 1 ppm and high
efficiency. The execution of topographic surveys using ProMark2 in the kinematic mode improves
the efficiency of the data acquisition and work performance.
It is possible to use ProMark2 during the work together with two or more receivers. It is also
possible to use ProMark2 together with traditional geodetic instruments. ProMark2 is equipped with
stakes, tripods, stands with an optical plummet and level, reducing bushings for using with different
types of stands and stakes, as well as with a user’s manual in Russian and software in Russian. The
ProMark 2 is packed in impact-proof and waterproof cases.
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.
Technical parameters of ProMark2
GPS satellite tracking: 10 parallel channels
Measurement of C/A code and full wavelength carrier L1
Tracking of WAAS and EGNOS satellites
2 independent channels
Accuracy of co-ordinate measurements
Static
Horizontal: 5 mm + 1 ppm
Vertical: 10 mm + 2 ppm
Azimuth: < 1"
The observation time ranges from 20 to 60 minutes depending on the distance
Measured distance: from 5 m to 20 km
Ashtech Solutions software
The Ashtech Solutions software allows to process data easily with high degree of reliability.
Main modules:
Planning of measurements
Automatic processing of vectors
Adjustment
Data analysis
Transformation of co-ordinates
Reporting
Data export
Drilling of geotechnical boreholes
Drilling of geotechnical boreholes is executed using mobile drilling rigs, which ensure the
performance of investigations in the complex conditions of rugged terrain. The drilling rigs are
equipped with various samplers for obtaining undisturbed samples (cores) and disturbed samples,
and sets of equipment for soil investigations in situ.
Hydraulic drilling rig GBU-5 (manufactured in the Russian Federation) on wheels with an
original movable hydraulic rotary table.
Its purpose is the drilling of core holes, water wells, exploration of deposits of hard minerals and
geotechnical investigations. The bottom-hole cleaning is executed by flushing, scavenging or
transportation of crushed rocks to the surface by augers. The rig provides soil testing using the cone
penetration method (CPT) in accordance with the State Standard (GOST) 19912-2001.
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The drilling rig GBU-5 ensures drilling using drill pipes with the diameter Ø63.5 mm; it is equipped
with a winch with the load-carrying capacity of 3.2 ton, with free running, for cable tool and
roundtrip operations.
The availability of a working winch and a movable hydraulic rotary table allow carrying out cable
tool drilling, repair of production wells, operations associated with the transportation of auxiliary
equipment and other operations. The rig mechanisms are mounted on a frame of their own, are
installed on the automobile chassis and are powered by the motor. The control of the rig, including
the hoisting (lowering) of the mast, is fully hydraulic-based; it is concentrated in the control unit of
the drilling foreman.
The technical parameters of the drilling rig GBU-5 are as follows:
The automobile chassis of heightened cross-country capability – KAMAZ-43114, URAL-4320. The
drive of the rig – hydraulic, from the automobile motor.
Load-carrying capacity of the mechanism of upward feed – 100 kN.
Load-carrying capacity of the drilling winch – 32 kN.
Push-in force of the penetration string with the probe during CPT – 100 kN.
Drilling depth, m (using pipes/auger) – 150/40.
Diameter of rotary drilling with flushing/auger drill – 250/up to 650, mm.
Torque of folding hydraulic rotary head – 400 kg*m.
Drilling pump – NB-50.
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Vibratory drilling rig AVB-2M (manufactured in the Russian Federation).
The purpose of the AVB-2M vibratory drilling rig is the drilling of vertical boreholes during
engineering-construction surveys using the vibratory method in the rocks with the categories of the
drillability indices I-IV and for cable tool drilling in the rocks with the category of the drillability
index of up to VII.
The rig is equipped with a vibratory hammer for lowering and extraction of casing and samplers.
The rig also ensures the drilling of boreholes and soil sampling using the cable tool method.
The technical parameters of the drilling rig AVB-2M are as follows:
Parameters
Borehole depth, m:
using vibratory drilling
using cable tool drilling
Borehole diameter, mm:
initial, using vibratory drilling
initial, using cable tool drilling
final
Load-carrying capacity of the winch, kN
Vibratory hammer:
Type
perturbing force, kN
unbalance weight moment, N · m
weight, kg
Mast:
load-carrying capacity, kN
operational height, mm
Dimensions in the transportation mode, mm
Weight, kg
Parameter values
15-20
40
168
219
108
40
VB-7
35
20
340
120
7500
7400x2300x3280
2327
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Various samplers are used in conjunction with the rig of our own manufacture, including push-in,
percussion samplers and corers.
Various samplers are used in conjunction with the rig of our own manufacture, including push-in,
percussion samplers and corers.
The mobile drilling rig Georig 707, manufactured by Geotech (Sweden), is utilised for geotechnical
operations in the rugged and boggy terrain. The rig is crawler-mounted, is hydraulically-driven and
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is capable of drilling in different modes: from percussion to diamond-core drilling, as well as of soil
investigations in situ using various types of equipment.
Dimensions
Length with folded/risen mast: 5.06 m
Height with folded/risen mast: 2.41/3.4 m
Width: 2.14 m
Clearance: 0.315 m
Drive
Motor: Perkins diesel (6 cylinders) 159 kW/2200 rev./min.
Movement speed: 0÷5 km/hr
Drilling rig
Rotary head stroke: 2.45 m
Pull-up force: ≅ up to 13 tf
Pull-down: ≅ up to 7 tf
Rotary head (with single/double spindle)
Diameter: Ø85 mm
Moment at spindle: ≅ up to 250 kg*m
Spindle velocity: 0÷85 rev./min.
Drilling depth: up to 150 m.
It is possible to use the THIN WALL ST:1 sampler with the Georig 707 rig.
THIN WALL ST:1 sampler or thin-walled tube with piston ST:1 has been designed by
the Swedish Geotechnical Institute (SGI); its purpose is to obtain high-quality undisturbed
soil samples from clay, silt, sandy loam or pure sand.
During the sampling, soil enters into 3 (epoxy-covered) liners with the internal diameter
Ø50 or Ø75 mm, preventing the internal walls of the tube from damage. The length of
each liner is 3 x 170 mm and 1 x 510 mm.
The sampling is executed using extension rods only, and no internal rods are used,
because the mechanism, which catches the piston, is surface-controlled using a special
new mechanism.
The sampler is lowered into the borehole by extension rods used for Standard penetration
tests with Ø42 mm to the sampling depth using the roundtrip mechanisms of the drilling
rig. The sampler is closed by the piston is kept empty until the sampling depth is reached.
This piston fills tightly the cylinder opening at the cutting edge. At the desired
depth, a conical tap attached to a chain is lowered through the inner diameter
of the extension rods, until the cone is gripped by a claw. The chain is pulled,
whereby a ball lock releases the piston rod. The chain is then firmly attached
to a fixed point, whereby the piston is locked at the given depth. The
extension rods are further pushed, pressing the sampling cylinder into the
layer to sample. The piston follows the sample up into the cylinder and keeps it.
When the cylinder has been filled, a claw opener releases the cone from the claw
and the chain retrieved from the extension rods. The sampler is then pulled
up and the cylinder ends are covered and protected with plastic and steel caps.
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Cone penetration testing of soils with measurements of pore pressure CPTu
Cone penetration testing (CPT) of soils is used for:
• The identification of geotechnical elements and boundaries of occurrence of soils of different
types and varieties.
• The evaluation of the spatial variability of the composition and properties of soils.
• The determination of the depth of occurrence of the top of rocks and clastic soils.
• The quantitative evaluation of parameters of physical and mechanical properties of soils
(density, deformation module, internal friction angle, undrained shear resistance of clayey soils,
specific cohesion etc.).
It is possible to use the CPT equipment in any above-mentioned mobile drilling rig.
CPT is carried out in accordance with the International Reference Test Procedure (IRTP)
recommended by the International Society for Soil Mechanics and Geotechnical Engineering for
soil testing using CPT and in accordance with GOST (State Standard) 19912-2001 by a probe using
a pore pressure sensor. The cone penetration testing is carried out using the equipment
manufactured by GEOTECH (Sweden).
If the planned depth of CPT exceeds 20 m, and dense soils are present within the geotechnical
section, CPT is executed using a drillstring consisting of plain drill pipes with the diameter 73/56
mm with a cutter head on end. The drillstring is used for ensuring the mechanical stability of the
string of penetration rods, as well as for drilling through intervals represented by rocks or dense
soils, where failures of CPT are observed.
The following parameters are measured during the testing:
qc – specific tip resistance under the cone of the probe;
fs - specific soil resistance on the friction sleeve;
u - pore pressure;
TA – tilt angle of the probe;
T°C - temperature (if there is a temperature sensor in the probe).
The recording of the measurement data is executed on a PC using signals from the depth sensor
with the sampling rate 2 cm and more. The testing results are presented as tables and graphs - as
soil columns and sounding graphs.
The soils are classified based on the calculated SCN values – the classification index of the soil
number according to Olsen’s diagram. The above-mentioned data are presented in the field report.
During in-office operations, calculations of the deformation and strength parameters of soils are
made: Su, φ, C, E, in situ and average values by layer.
Based on the СРТ, calculations of the bearing capacity of soil foundations and piles are made.
CPT equipment NOVA RW
This is a cordless system of cone penetration testing, in which data transmission by radio waves is
used. Following many years of studies and improvements, NOVA RW is a system with quite high
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efficiency. The utilisation of a cordless CPT system excludes the necessity of operations aimed at
the cable pulling and connecting, thus ensuring higher productivity.
The utilised format: 17 Bit transformation in real time.
The rods are jointed during the testing.
The testing method and equipment comply with the requirements of the international standard
ISO22476-1, the US standard ASTM D-5778, with the following parameters:
RW transmitter block
Length: 430 mm
Diameter: 36 mm
Energy supply: 4 lithium batteries LR14
Endurance: 12 hours
RW receiver block
Length: 210 mm
Diameter: 60 mm
Protection: IP 67
Temperature range: from -20 to +50 °C
Energy supply: 12 V DC
СРТ cone
Cone resistance (qc):
Cone section: 10cm2
Angle at cone apex: 60 deg.
Area factor: 0.82
Measurement limits: 20, 50 and 100 MPa
Accuracy: < 0.2% of measurement limit
Resolution: < 0.0025% of measurement limit
Sleeve friction, (fs)
Area of the friction sleeve: 150 cm2
Area factor:0.0
Friction measurement limits: 0.5 and 1 MPa
Accuracy: < 0.2% of measurement limit
Resolution: < 0.0025% of measurement limit
Dynamic pore pressure, (U)
Measurement limits: 1, 2.5 and 5 MPa
Accuracy: < 0.4% of measurement limit.
Resolution: < 0.0025% of measurement limit
Tilt sensor with dual-axis accelerometer
Range: 0-40 deg.
Accuracy: 0.5 deg.
Resolution: 0.1 deg.
All sensors are temperature-compensated.
1 - CPT probe; 2 - RW transmitter; 3 - RW
receiver; 4 - depth sensor; 5 - interface block;
6 - PC.
Cone penetration testing of soils with measurements of pore pressure and seismic acoustic
channel SCPTu (SEISMIC CPTu)
This is CPT equipment with the transmission of measurement data from the probe to the interface
block of the PC by cable. The equipment ensures the execution of seismic investigations using a
built-in adaptor.
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The seismic sounding using the SCPTu method is carried out by pushing in of a single-axis or
triple-axis adaptor to the necessary depth and recording of the time of propagation of the shear and
elastic waves from the surface to the SCPTu adaptor in the probe, during the generation of seismic
signals, using, for example, a sliding hammer. The time of arrival of acoustic waves is measured
using the software of the acquisition of the SCPTu data - SCPTLog.
Seismic SCPTu sounding is carried out alongside with the measurements of pore pressure. When
the sounding is interrupted, dissipation testing is possible as well.
In order to simplify the acquisition of data, the equipment and software have been developed to be
PC-based, incorporating the system of agreement with uniaxial and triaxial signals, instead of a
traditional seismograph. In order to ensure the qualitative evaluation and proper analysis of data,
frequency filtering of data is carried out after their acquisition, rather than during the recording
process. In order to determine the frequency of the spectrum of the recorded signal, i.e. in order to
avoid distortion, the cone adaptor is equipped with an accelerometer (1 Hz - 10 kHz), rather than
geophones (typically 1 - 300 Hz).
Set of SCPT equipment
Format of output of results of measurements and processing using software of data acquisition and
analysis (SCPT Analysis).
The system of agreement using the uniaxial and triaxial adaptor consists of two main components:
the signal agreement unit and the PCMCIA card.
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The unit consists of a differential pre-amplifier, amplifier with programmable gain, programmable
low-pass filter and the trigger unit with programmable gain.
The data analysis is executed using the software of Geotech (SCPT Analysis) or any other software
using similar format. The velocities of elastic and shear waves between the measured levels along
the section depth are obtained as a result.
That is possible to do in the field during the testing; besides, the possibilities of qualitative
evaluation are improved.
TECHNICAL PARAMETERS:
Seismic adaptor: for all Geotech probes, uniaxial or triaxial.
Sensors: one shear wave accelerometer per axis.
Frequency range: 1 Hz - 10 kHz.
The signal agreement system: the signal agreement unit (uniaxial or
triaxial) and the PCMCIA card.
Acquisition and analysis software: SCPT-log. SCPT-Analysis.
Seismic source: falling hammer.
Standard penetration testing
Standard penetration testing (SPT) is carried out using a special unit, which ensures the penetration
of a mechanical probe (without built-in measuring sensors) into the soil by percussion.
During SPT, the depth of the probe penetration h from a certain number of hammer blows is
measured. Based on the measurement data, the conditional soil resistance to the penetration of the
probe Pd is calculated.
SPT equipment
Geotech-manufactured unit is used for SPT.
The SPT unit manufactured by Geotech has been
developed for use together with all multi-purpose
drilling rigs manufactured by Geotech (604D and
605D, see the advertising booklet) and the 22004
penetrometer; it is simply mounted on any rig
suitable for the execution of geotechnical
operations. CPT is used predominantly for the
determination of properties of unconsolidated
soils.
Based on the results of SPT, the lithological
structure of the soil section and soil resistance to
sounding are determined. The hammer falls from
the predetermined height and hits the string with
the mechanical SPT probe to which new rods are
added. In accordance with the standard for SPT
(Standard Penetration Testing-SPT), a standard
steel sampler could be added to the rod string to
carry out a combination of SPT and soil sampling.
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The weight of the hammer and the height of the fall comply with the users’ specifications,
depending on the requirements of different international standards DPH, DPSH-A (HfA), DPSH-B
(SPT).
During SPT, a continuous profile of soil resistance to penetration is recorded, which reflects the
mechanical parameters of soils measured as the number of blows to a certain depth.
The selection of dynamic methods is presented in the table below.
Cone area Hammer weight Fall height Depth interval
DPM
DPH
10 cm²
30 kg
50 cm
10 cm
15 cm²
50 kg
50 cm
10 cm
DPSH-A (Hfa)
15 cm²
63,5 kg
50 cm
30 cm
DPSH-B (SPT)
20 cm²
63,5 kg
76 cm
30 cm
Field vane testing (FVT)
Soil testing using field vanes is carried out in order to determine soil resistance to shear Su, the
index of soil shear structural strength (clay sensitivity), and the character of spatial variability of the
soil shear strength.
The units consisting of the following main equipment are used for
FVT: the vane, the rod, the device for the creation and measurement
of torque.
Geotech-manufactured unit and equipment with electrical sensors are
utilised for FVT (field vane test-electrical).
Two types of the equipment are manufactured:
Standard – without the vane protection;
Complying with the Eurocode – with the vane protection.
Testing of undrained shear strength Su and sensitivity of clay.
Measurement limits: 0-50, 0-100 and 0-200 kPa;
Measurement accuracy: < 1% of the measurement limit.
FVT is one of the most widespread methods for measuring the undrained shear strength and
sensitivity of cohesive soils. FVT has been carried out in various climate zones all over the world
during the last 40 years by the companies Geotech and Nilcon.
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There are two versions of the equipment: with the vane protection in accordance with the Eurocode
and without protection.
Both versions of the equipment are electrical; its purpose is the measurement and recording of
torque and cohesion. The vane is introduced in soil using an instrument mounted on the push-in
(penetration) unit. In the standard version, the string to which new rods are added goes through the
recording device, i.e. the instrumented head need not be detached to carry out each measurement. In
the model complying with the Eurocode, everything depends on the testing interval and the stroke
length, where the instrument must not be remounted. Both the vane in the protection case and rods
of the penetration string could be introduced in soil with the device complying with the Eurocode.
The electrical vane complying with the Eurocode is supplied together with the protection case, the
purpose of which is to remove most of the friction on the side surface and the protection of the vane
during the penetration into the soil. The disconnector is mounted between the rod string and the
vane to measure the friction between the rod string and the protection case. The standard field vane
equipment does not have a protection case. A disconnector similar to the Eurocode model is used to
measure friction on the side surface of the rod string.
The applied torque, measured by a load sensor, and the angle of rotation are recorded after each 0.5
degrees in the PC. The configuration of the recorded dependence ensures the control of the
correctness of the execution of the test and the nature of the soil. The torque for the rotation of the
rod column must be recorded first of all, and, subsequently, the full torque for the rotation of the rod
column and the vane until the moment of the soil destruction. The difference between those values
is utilised for the calculation of the soil shear strength. The dependences are stored in individual
files for each test.
Using the Geotech’s software (Vane-Log) for the data acquisition, the soil shear strength is
determined; there is also the possibility of the calculation of the rod friction and the determination
of the dependence of the change of torque on the vane turning angle.
The vane is manufactured from high-quality chrome-nickel steel and has been designed specifically
for pushing into soils with as little disturbance as possible. The standard vane model has a wedgeshaped cusp in the lower part to improve the penetration.
Technical parameters of the model complying with the Eurocode:
The vane (Ø x h, range): 65 x 130 mm, 200 kPa;
The blade type: rectangular on two sides;
The protective shell of the vane: external Ø75, length 820 mm;
The protection case: external Ø42 mm;
The string rods: Ø22 x 1000 mm;
The disconnector: 15° clockwise.
Technical parameters of the standard model:
The vane (Ø x h, range: 50 x 110 mm, 200 kPa;
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65 x 130 mm,100 kPa;
80 x 172 mm, 50 kPa;
The blade type: rectangular on two sides;
The string rods: Ø22 x 1000 mm;
The disconnector: 15° clockwise.
The recording instrument:
Dimensions LxWxH: 360 x 210 x 110 + connector, 140 mm
Measurement limit: 100 N x m
Measurement accuracy: < 1 % of the measurement limit
The clamp: distributed along the axis length, 125 and 85 mm on each side.
Determination of physical and mechanical properties of soils in situ using
Pocket Vane (P-vane)
The pocket vane is used for the preliminary evaluation of the undrained shear strength Su and the
consistency of the clayey soils. Clayey water-saturated soils with the undisturbed structure from
soft to stiff are the sphere of the use of the device.
The device - Model 16-T0175/A is a device equipped with a spring, with a blade tip and the scale
calibrated in N/cm2. Besides the main tip, the device also has two extra removable ones. The
selection of the tip type depends on the soil consistency.
The dial of the Pocket Vane is marked for the normal tip, from 0 to 10 N/cm2, which is equivalent
to the determination of Su within the range from 0 to 100 kPa.
In order to test a sample with the undisturbed structure, a smooth clean surface is prepared, with the
diameter of at least 2.5 cm. Then the Pocket Vane is carefully pushed into the soil to the depth of
the tip blade. By the effort of fingers, constant vertical pressure is provided, and a slow turning of
the head is executed during 5-10 seconds until the failure of the soil occurs. The readings of the
indicator at the moment of the failure of the soil provide the value of shear strength SU, which
corresponds to undrained testing in the triaxial testing equipment. The readings are read out. The
indicator returns to zero, and the device is ready for work once again.
The average measured reading (out of 3) of the device in N/cm2 is transformed into kilo Pascals
(kPa) using the conversion factor for the relevant tip.
Based on the obtained evaluated values of the undrained shear strength, preliminary evaluation of
the soil consistency is made within the framework of the classification of GOST 25100-95, ASTM
or BS5930.
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The measurement results are accumulated in the form of tables and are produced in accordance with
the approved requirements for the preparation of the field report documentationии.
Determination of physical and mechanical properties of soils in situ using Pocket
Penetrometer (P-penetrometer)
The Pocket Penetrometer 16-T0171 manufactured by “Controls” is used for the preliminary
evaluation of the physical and mechanical properties of soils, including the consistency of the
clayey soils and undrained shear strength Su. It ensures quick determination of the abovementioned physical and mechanical properties right after the extraction of the sample from the
sampler.
The Pocket Penetrometer 16-T0171, Controls
The utilised device - Model 16-Т0171 represents two telescopically connected cylinders with an
internal compression spring. The tip of the internal cylinder
(marked by cut) is for pushing into the soil sample. The force of
the resistance to penetration is read from the indicator scale of
the device, calibrated in kg/cm2. That model can be used both in
the laboratory and field conditions for working with soils with
the undrained shear strength from 0 to 4.5 kg/cm2.
In order to execute the testing of a sample with the undisturbed
structure, a smooth clean horizontal surface is prepared.
Subsequently the tip of the device is carefully pushed into the
soil until the cut on the tip is reached; during that process, by the
effort of fingers, constant vertical pressure and vertical position
of the device are provided.
Based on the obtained evaluated values of the undrained shear
strength, preliminary evaluation of the soil consistency is made
within the framework of the classification of GOST 25100-95, ASTM or BS5930
Laboratory testing of soils for the determination of their physical and
mechanical properties
The laboratory investigations envisage the determination of the composition and physical and
mechanical properties of soils using the nomenclature, which ensures the execution of the necessary
geotechnical and engineering calculations. Descriptions of the received soil samples are prepared
before the initiation of the tests.
The laboratory testing is carried out in accordance with BS 1377. The existing laboratory equipment
and devices ensure the determination of all indices of the soil propertied, which are mentioned in
the “Specification for geotechnical investigations”.
The following equipment and devices are available for the testing and analysis of the
parameters of the obtained soil samples in the onshore laboratory
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Type of test
Soil density,
moisture content
Density of soil
particles
Atterberg limits
Grain size
composition
(sieve,
hydrometer)
Carbonate
content
Shear testing
Triaxial testing
(HH)
Equipment
Scale - Oven 225 (40-200°C)
Scale with balance beam - Top Pan Balance ADP-3100 g,
resolution 0.01g
Scale -Top Pan Balance ADP-360g, resolution 0.01g
Vacuum pump 45 l/min., 240 V/50 Hz
Refrigerated Circular 240V/50 Hz
Vacuum dessicator Ø 250 mm with lid
Pycnometer 100 ml with thermometer (0-30)°C
Motorised device for the determination of yield strength in
accordance with BS-1377
Fabric wire net (BS-410) Ø 200 mm, set of sieves (63
micrometres – 75 mm)
Sieving machine
Hydrometer for soils, calibrated from 0.995 to 1,030 q/ml
in accordance with BS-1377
Calibrated glass measuring cylinder with the volume 1000
ml
Steam bath with temperature controller
Calcimeter, burette for calcimeter (volume 250 ml)
Device model
WF-61020
WF-60046
WF-60044
WF-33312
Julabo F34
WF-32926
WF-21520
WF-62020
WF-23860
Fijkelkamp
0853: 085301
Direct shear apparatus
WF
Compression testing apparatus „TRISTAR” - 5000 kg
WF
The working chamber, max. pressure 1700 kPa; Force in
the chamber 5 kN
Pressure sensor 1000 kPa; burette 50 ml; pressure gauge 12
bar; digital indicator (50 ml); Nold de-airing system;
Air compressor; Vacuum pump
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Engineering-geophysical operations
Engineering-geophysical operations are an integral part of geotechnical surveys during all stages of
their execution (the project, working documentation).
The engineering-geophysical surveys supplement the net of geotechnical drilling, improving the
information content of geotechnical investigations. The main methods of engineering-geophysical
surveys are as follows: seismic, electrical surveys and georadar.
Seismic reflection method – Mini-CDP
The seismic reflection method in its modification – common depth point (CDP) ensures the
maximum depth out of all methods utilised in shallow seismic. The system of observations
envisages rather high density of shotpoints of elastic waves and signal reception points per line unit
with the purpose of ensuring multiple coverage during the tracking of the reflector boundaries. The
technology of the operations is quite labour-consuming, but it ensures the acquisition of most
reliable information about the geometry of boundaries of the subdivision of physical properties in
the investigated space, which are associated not only with layering, but also with possible
discontinuities of rocks due to tectonic movements.
Elevation mark of a relief, m
Statistical correction for source position, ms
Time cross section of CDP
Fig.1 Time section for the line Rost.3.03. The Verhne-Kamskoe deposit of potassium salt, July 2003. The line was shot
using a 40-kg falling weight with accumulation of 4 impacts. The height of hoisting the weight – 3 m. The shotpoint
interval along the line – 8 m, the interval of the receiver channels – 8 m, central spread, 48 channels, the length of the receiver
base – 384 m. Receiver groups – 5 geophones manufactured by OYO per channel, group base – 16 m. The recording
equipment –the seismic station IS-128-01 (Interseis, Latvia), the sampling rate – 0.5 ms. Filtering at reception – 14/500 Hz.
terrigenous-carbonate formation
salino-marlaceous formation
transitive geological unit
Pokrovsk stone salt
top of carnallite zone
bottom of productive formation
bottom of all salt formation
In many cases, the use of most simple and environment-friendly surface sources of elastic waves of
the falling weight type (Fig. 2) allows to obtain quite strong reflections from boundaries at the depth
of 500-600 m.
The usual task during engineering surveys is to investigate the properties of the soil massif and the
bedrock to the depth 40-50 m. Sometimes there are specific tasks, which require the increase of the
depth to 150-200 m.
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Fig.2 Excitation of elastic
oscillations using the surface
source of the “falling
weight” type (the weight - 36
kg).
SEISMIC ACOUSTIC INVESTIGATIONS IN BOREHOLES
During seismic acoustic investigations in water-filled geotechnical boreholes, the reception of
oscillations is executed using a hydrophone probe, which is lowered into the borehole. The
excitation of oscillations is carried out either on the surface or in an adjacent working – mine or
well. In order to obtain a spatial image of the distribution of physical properties of the investigated
massif, several lines are used, which form an areal grid of shotpoints on the surface of the massif
(Fig. 3). That allowed to carry out the survey using the so-called “semi-topographic” scheme with
the investigation of a pyramid volume around the borehole under investigation.
Fig.3 Scheme of line positions
with initiation points on the
surface
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Fig.4 Scheme of positions of initiation points in
a shaft and the ray scheme during the
observations using the method of interwell
sounding (seismic tomography)
The records, obtained using the method of seismic tomography, allow to obtain the most detailed
and reliable images of the distribution of physical properties of the investigated massif in the plane
of the ray propagation between two workings due to the highest and uniform density of seismic rays
(Fig. 4)..
EQUIPMENT
SEISMIC ACOUSTIC RECORDERS IS128-02, IS128-03
Seismic acoustic recorder IS128-02
Seismic acoustic recorder IS128-03
The purpose
• seismic acoustic investigations with the frequency range from 2 Hz up to 8 kHz,
• profiling at the ground surface and in shallow boreholes,
• investigations of the upper part of geological section using refracted, reflected
and surface
wave techniques,
• geotechnical investigations,
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• control
of the technical condition and geological and geophysical monitoring of onshore
and offshore structures,
• acoustic investigations of the road pavement, substructures and foundations,
• offshore shallow seismic acoustic surveys and continuous subbottom profiling in singlechannel and multi-channel modes.
During operations with relatively weak power sources of the initiation of seismic pulses, the recorder
provides the stacking of weak signals. The stacking of seismic acoustic signals using hardware is
carried out before the record transmission to the long duration memory on a hard disk. Remote 16channel distributed modules with low power consumption can be connected to the central module via
two-wire high-speed USB-RS485 interface or WiFi radio interface.
Configuration
System of synchronisation of initiation and reception:
• by forming the initiation pulse and its transmission to the seismic source,
• reception of the synchronisation pulse from an external source.
The recorder is capable of simple programme interactive diagnostics, including the device, which
forms test signals with analogue output and which facilitates the control of the workability of the
equipment, search and elimination of failures in the field conditions.
The design of the recorder allows its use in the conditions of high dust content and humidity. The
equipment retains its performance capacity at the temperature of the surrounding air from 0 to
+400C, relative humidity of up to 98% at +250C and relative pressure (750 +/-30) mmHg.
The service programme ensures the stacking of signals, storage in the file and imaging of data on
the monitor screen. The programme is also capable of simple record pre-processing procedures
immediately after the acquisition, as well as the spectral analysis of the records. The set of
procedures also incorporates an analysis of amplitude-frequency characteristics of seismic signals in
different recording modes based on test records.
During the offshore operations, for the geodetic positioning of data, the GPS receiver is connected
to the COM port of the master computer, and continuous recording of co-ordinates in the seismic
line label is executed.
The recorder has been designed for the utilisation, primarily, in hardly accessible terrain, in
geotechnical boreholes, inside industrial facilities and underground workings, as a distributed
system for the acquisition of seismic acoustic data. It has been designed based on the latest
electronic components, and has quite high indicators as regards energy consumption, weight,
dimensions and simplicity of communication lines.
The existence of several autonomous remote modules in the recorder system allows to use
sufficiently flexible linear, areal and spatial observation systems. As an option, two or more remote
modules can be placed within the case of the central module; in that case, the recorder represents a
usual geotechnical seismic station with the number of channels from 16 to 64.
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Starting geophone
Flowchart of data collection and processing
Synchronization pulse
Central module
Remote module
Geophones
Geophones
Сервисна
Record obtained using a percussion source 8 kHz using
four modules, sampling rate 200 mcs,
channel step 2 m.
Placement of a remote module in a shockproof and waterproof case OtterBox CQ5000
The power supply of the central module is from a DC source 9-18 V, usually from an external leadacid battery 12-17 A/hr. The remote modules have built-in lithium batteries, 7.4 V, 2A/hr. The
current consumed by a remote module in the operational mode (with the buffer disabled) does not
exceed 250 mA, comprising 350 mA with the operational buffer. The activation of the buffer
increases the input resistivity, which allows to increase the sensitivity of the seismic channel manyfold. When the cable of the interface RS485 is disabled, the module enters the “sleep” mode with
the consumption of maximum 30 mcA. When the minimum permissible voltage in the accumulator
is reached, the module is switched-off automatically.
Main technical parameters
1) Number of utilised modules (is set by the user)
2) Number of channels of the remote module
3) Input resistivity (is set by the user)
4) Frequency range at -3 dB
5) Dynamic range at dt=1ms
6) Bit depth conversion, delta/stigma
7) Amplitude sampling period
8) Stacking, 32 bit output code
9) Initial amplifier gain
10) Frequency of initiation pulses
11) Anti-alias
Окfilter bandwidth
12) Low-cut filter
13) Rejection filter
14) Counts per channel (optional)
15) Noise level at input at 1 ms
1-16
16
0.001-100 MOhm
2-8000 Hz
130 dB
24 Bit
0.03 - 4.0 ms
256
6, 12, 18, 24, 30, 36 dB
up to 2 per sec.
125 - 8000 Hz
36 dB/octave
50, 100, 150 Hz, 48 dB
192/16384
1.3 mcV
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16) Input signal range
17) Crosstalk ratio at 100 Hz
18) Suppression of equiphase noise
19) The format of output code integers
20) Primary power source
21) Host processor
22) Data transmission
23) Random access memory
24) HDD
25) Display LCD TFT 12,3”, SVGA
26) The keyboard: membrane, protected
27) Degree of environmental protection b
28) GPS Protocol
29) Dimensions of the host module
30) Weight of the host module
31) Dimensions of the remote module
32) Weight of the remote module
33) Ambient temperature:
host module
remote module
Connection оf geophone sections to the remote
module on the line
+/- 5 V
< -100 dB
>110 dB
32 digits
12 V
PCM-5820
USB, RS485
256 MB
30 GB
800x600
56 keys, IBM AT
IP65
NMEA-183
378х330х178 mm
8.0 kg
171х121х55 mm
1.1 kg
0°С -+40°С
-20°С -+50°С
Interface and synchronisation module
The connection of remote modules to a usual laptop PC is the most convenient as regards the
technology of field operations and noise suppression in the recorded signals; it is executed via a
USB port, using a specialised high-frequency convertor USB-RS485 and block of synchronisation
of records.
In that case, separate geophone cables are connected directly to the remote modules on a seismic
line, which are joined to each other and connected to the interface module via a two-wire digital
line. Due to that, the impact of the electromagnetic noise level on the signal and extension cables is
greatly reduced. The data transmission from the interface module to the PC is executed either via
the two-wire line or by radio, via a WiFi interface, if the communication distance does not exceed
100-120 m.
Software of data acquisition and processing
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The service programme works in the environment of the operation system Windows98/XP. The
test module of the programme allows to check up the main technical parameters of seismic
recording channels, to provide examination channel-by-channel and calculation of statistical
parameters of the records, and to carry out the spectral analysis of the records.
The set of window menus makes it possible for the operator to set the parameters of recording and
receiver geometry easily and graphically.
Windows of settings of recording and receiver geometry
A synthetic seismogram, obtained after the transmission of data from several remote modules is
shown in a working window of the acquisition programme, as well as the level of charge in the
built-in batteries of the remote modules, the number of the current initiation in the stacking series,
the current record number and the process of the signal transmission. Using the scroll line, long
records with the selected degree of detail could be seen.
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GEORADAR SURVEYS
It is possible to use georadar for simpler geotechnical investigations, for example, during surveys
for the road construction, determination of the condition of pavement, when it is necessary to
investigate the properties of the soil massif to the depth of maximum 20-30 m.
The georadar is a geophysical instrument for fast soil profiling. The principle of the georadar action
is based on the emission of very wide band pulses of the metre and decimetre range of the
electromagnetic waves and the reception of signals reflected from objects or inhomogeneities,
which have dielectric permeability or conductivity that is different from that of the environment.
The reflected signal is transformed into the digital format and is imaged on the display. The PC
allows to see the obtained results and to execute the necessary processing procedures.
In order to obtain data from different depth, aerial blocks are used, working using different
frequencies. The general rule is as follows: the lower is the working frequency of the aerial, the
greater is the depth of the signal penetration, but the resolution decreases and vice versa.
The following problems could be solved using the georadar.
During the stage and design of highways
Investigations of the geotechnical conditions at sites subjected to deformations:
• determination of the depth of groundwater and occurrence of vadose water;
• mapping of the top of the rock foundation;
• identification of zones of occurrence of specific soils (peat, silt, salted soils etc.;
• determination of the position of the top of permafrost;
• investigation of taliks and cryopegs;
• determination of dynamics of cryological phenomena (zones of seasonally frozen soils);
• mapping of underground communications.
Investigations of hazardous geotechnical processes:
• landslides;
• quicksand;
• karst phenomena.
During the stage of exploitation and reconstruction of road pavements
Control of the compliance of the pavement with the design documentation.
Investigation of the condition of the construction layers of the pavement.
• determination of the thickness of the construction layers of the pavement;
identification of subsidence;
• identification of failed and flooded areas.
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Power supplay unit 9/12
Hanger with laptop
Composition of equipment and
scheme of utilisation of
georadar:
Optical transformer
Optical cable
Control unit
Handle
Electrical cable
Mono ski
Path meter
Aerial block
Examples of investigations of roads and runways
distance along a profile, m
distance along a profile, m
Peat
Depth, m
reflection arrival time, ns
Sand
Sand-Silt
variation
Clay
Georadar “OKO”
The "OKO-2" georadars are the recognised leaders among similar Russian products.
The instruments are certified and patented.
Based on their technical parameters, the "ОКО-2" georadars are on the level of georadars
manufactured by the leading world manufacturers, exceeding some parameters of similar foreign
equipment.
The set of the "ОКО-2" georadar incorporates the basic set and the aerial blocks, which are selected
depending on the task. The aerial blocks are exchangeable. Using an aerial block with a lower
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frequency, it is possible to increase the depth of investigations, but, if it is necessary to achieve a
high degree of detail in the investigations of the top part of the section, high-frequency aerial blocks
should be used. A combination of the aerial blocks with different frequencies is optimal. Both
shielded and unshielded aerial blocks are used in the "ОКО-2" georadars.
The "OKO-2" georadar has full optical decoupling as regards the signal and information chains,
which improves the performance of the instrument under complex conditions.
The "OKO-2" georadar has intelligent shielded aerial blocks for different frequencies, equipped
with a microprocessor for pre-processing the acquired information. All the aerial blocks of the
"OKO-2" georadar can operate with three types of motion sensors (wheel, coil, automobile sensor).
The software of the georadar supports the operation of the georadar in conjunction with GPS
receivers.
The processed data are output in different formats, such as SEG-Y, CSV, HTML, EXCEL,
supported by standard software packages (MATLAB, AUTOCAD etc.).
There is a specialised microprocessor processing block for the operation in adverse weather
conditions (rain, frost, bright sun etc.); it allows to operate at the temperature from - 20° to + 50°C;
the ABDL aerial block “Triton” (flexible aerial) allows to carry out surveys in the tundra, forest, on
water and underwater.
The control block provides the control of all operating modes of the georadar, executes preprocessing of the acquired data and transforms the signal received from the aerial block into
standard signals for the laptop (Ethernet, USB).
The aerial blocks are used of the "ОКО-2" georadar consist of the receiver and the transmitter
blocks. The aerial blocks are subdivided into two categories – those with the optical decoupling as
regards the signal and information chains and those without it. In the aerial blocks with the optical
decoupling, the receiver and the transmitter blocks are powered by separate power sources, and an
optical cable is used for the transmission of the signal from the path meter from the receiver block
to the transmitter block. In the aerial blocks without the optical decoupling, the power is provided
through an interface cable from the control block. All the aerial blocks are dust- and waterproof.
The power consumption is approximately 7-8 W.
ELECTROMETRY
The data of multichannel electrical profiling using the resistivity sounding (electrical tomography)
allow to evaluate, predominantly, the character and degree of the saturation of the soil massif by
fluid. It is possible to provide a more complete evaluation of the condition of the soil massif as a
foundation for the structure under design in conjunction with the data of seismic using different
types of waves.
REPORTS
Field reports are presented after the completion of field operations. They contain information about
the technology and volume of the completed operations. Initial data are submitted for consideration
(sections, diagrams, columns etc.).
Preliminary reports are submitted after the completion of field operations. They contain preliminary
results of data processing and conclusions about the geotechnical conditions at the investigated site.
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The Technical Report is submitted after the completion of geotechnical investigations. It contains
final results of investigations, results of calculations, necessary for the development of the project
aimed at the construction of an object.
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