Multi‑functional Specimen Preparation and Testing System
(Multi‑functional Consolidation Apparatus) Model BTU-CSA-3
Description
This equipment is amulti‑functional specimen preparation and testing system
(multi‑functional consolidation apparatus), modelBTU-CSA-3. It is mainly used for preparing homogeneous soil specimens and
performing various consolidation tests. The system offers
high‑precision control of stress and deformation conditions, with a
high degree of automation. The entire testing process can be
computer‑controlled via servo control, with real‑time acquisition
and analysis of specimen surface conditions, internal stress‑strain
state, and internal pore water pressure distribution. Main
functions:
- Preparation of homogeneous soil specimens
- Step‑loading consolidation test
- Constant rate of strain (CRS) consolidation test
- Constant rate of loading (CRL) consolidation test
- Real‑time measurement of pore water pressure at multiple positions
Test Standards (International)
- ASTM D2435(One‑dimensional consolidation of soils)
- ASTM D4186(Constant rate of strain consolidation – CRS)
- ASTM D4546(Load‑unload‑reload consolidation)
- ISO 17892‑5(Consolidation test)
- BS 1377‑6(Consolidation test)
- ASTM D698(Compaction test – related to specimen preparation)
The equipment can meet the requirements of these standards for
loading control, displacement measurement, pore pressure
monitoring, etc.
Specification
| Parameter | Specification |
| Model | BTU-CSA-3 |
| Instrument name | Multi‑functional specimen preparation and testing system
(multi‑functional consolidation apparatus) |
| Control accuracy | ±0.1% of full scale |
| Control modes | Electromagnetic switch + software + LCD panel (bidirectional
control) |
| Loading system | Servo motor mechanical loading |
| Load frame | Integral structure, good rigidity, stable, low vibration |
| Max. axial load | 30 kN |
| Axial effective stroke | 600 mm |
| Loading speed | 0.00001 – 9 mm/min, stepless adjustment |
| Load measurement and control accuracy | ±0.1% FS |
| Displacement measurement accuracy | ±0.1% FS (assumed, same as load) |
| Pressure cell | Custom, specimen size Ø300 mm × H600 mm, material 304 stainless
steel; capable of real‑time pore water pressure measurement at
multiple positions |
| Data acquisition and control system | Includes data acquisition/control system, various sensors, PC‑based
acquisition and control software |
| PC software functions | Communication with lower‑level controller, automatic servo feedback
control, sensor calibration; supports step loading, CRS, CRL, etc. |
| Load cell | 30 kN, with mounting accessories and data logger |
| Servo control cabinet | 240×128 LCD display, 20‑key keypad; controls vertical loading;
acquires displacement, load, etc. |
| Water collection tank | 20 L, for collecting drainage from the specimen during testing |
Detail
- Multi‑function integration– Can both prepare homogeneous specimens (e.g., by compaction or
consolidation moulding) and perform various consolidation tests
(step loading, CRS, CRL).
- Large specimen size– Pressure cell Ø300 mm × 600 mm height, suitable for
coarse‑grained soils or large specimens, reducing scale effects.
- High‑precision servo control– Load, displacement, and speed are servo closed‑loop controlled,
accuracy ±0.1% FS.
- Multi‑position pore pressure measurement– Pore pressure sensors can be installed at different heights in
the pressure cell to monitor internal pore water pressure
distribution, useful for effective stress analysis in saturated or
unsaturated soils.
- Wide loading speed range– 0.00001–9 mm/min, covering creep, slow consolidation, and rapid
loading.
- Long stroke– 600 mm, allowing large deformation consolidation or compression
tests.
- Water collection tank– 20 L capacity for collecting drainage, facilitating volume change
measurement.
- Flexible control– Can be operated via electromagnetic switch, software, or LCD
panel, accommodating different user preferences.
- Durable material– Pressure cell made of 304 stainless steel, corrosion‑resistant
for long‑term use.
Application
- Homogeneous specimen preparation– Provides uniform, repeatable specimens for subsequent triaxial,
direct shear, permeability, etc., tests.
- Large‑scale consolidation tests– Determine consolidation characteristics of coarse‑grained soils,
rockfill, soft rock, etc.
- CRS/CRL rapid consolidation– Quickly obtain consolidation parameters, saving time.
- Pore pressure distribution studies– Study internal pore pressure evolution under different drainage
boundary conditions, verifying consolidation theory.
- Long‑term creep– Measure deformation and pore pressure changes under constant load
to analyse secondary consolidation behaviour.
- Environmental geotechnics– Study consolidation behaviour of contaminated soils, expansive
soils, etc.
Advantages
- High precision– Control accuracy ±0.1% FS, meeting research requirements.
- Large size and long stroke– Ø300×600 mm specimen, 600 mm stroke, suitable for large
deformation and large‑particle materials.
- Multi‑function– Specimen preparation + step loading + CRS + CRL + multi‑position
pore pressure measurement – all in one system.
- Fully automatic servo control– Computer control, real‑time data acquisition, automatic parameter
calculation.
- Multi‑position pore pressure– Allows study of spatial pore pressure distribution, unlike
conventional single‑sensor measurements.
- Large‑capacity water collection tank– 20 L, suitable for drainage collection from large specimens.
- Flexible operation– Panel keypad + LCD + software, multiple control options.
- Robust construction– Integral load frame, high rigidity, low vibration.
What To Choose
Select this equipment or compare with other models based on testing
requirements:
| Requirement | Recommendation | Reason |
| Need homogeneous specimen preparation and consolidation testing | Very suitable | Integrated specimen preparation and consolidation |
| Need large‑size specimens (coarse soils, rockfill) | Ø300×600 mm meets needs | Avoids scale effects |
| Need CRS or CRL consolidation | Supported | Standard features |
| Need multi‑position pore pressure measurement | Supported | Multiple sensors can be installed |
| Only routine small‑size consolidation (Ø61.8 mm) | Consider a small consolidometer (lower cost) | This system is large and more expensive |
| Need higher axial load (>30 kN) | Do not choose this model; select higher‑capacity model | Maximum is 30 kN |
| Only specimen preparation, no consolidation | Choose a dedicated specimen preparation apparatus | Lower cost |
| Low demand for pore pressure measurement | Simplify configuration (fewer pore pressure sensors) | Reduce cost |
Process Flow
Example:Homogeneous specimen preparation + CRS consolidation test (with
multi‑position pore pressure measurement)
- Specimen preparation
- Mix soil to target water content, place into the pressure cell
(Ø300×600 mm) in layers.
- Use the servo loading system to compact each layer to target dry
density, producing a homogeneous specimen.
- During preparation, embed pore pressure sensors at different
heights (e.g., at 1/4, 1/2, 3/4 of specimen height).
- Installation and sealing
- Install the top cap, connect loading piston, displacement sensor,
and multi‑channel pore pressure sensors.
- Connect drainage lines to the water collection tank (20 L).
- If saturation is required, perform vacuum saturation or back
pressure saturation.
- Set test parameters
- In the software, select “CRS consolidation module”.
- Set a constant strain rate (e.g., 0.01 mm/min).
- Set maximum axial strain (e.g., 20%) or maximum axial load (30 kN).
- Set data acquisition interval (e.g., 1 second).
- Start the test
- The servo loading system pushes the piston downward at a constant
rate.
- The software records axial load, axial displacement, pore pressures
at multiple positions, and time in real time.
- Plots stress‑strain curve and pore pressure‑strain curves for each
sensor.
- Stop condition
- Automatically stops when the preset strain or maximum load is
reached.
- Disassembly and cleaning
- Unload, remove the specimen, measure final water content.
- Clean the pressure cell, pore pressure sensors, lines, and water
collection tank.
- Data processing
- Based on CRS theory, the software calculates the overall
coefficient of consolidation Cv (using average or bottom pore
pressure).
- Compare pore pressure responses at different heights to analyse
pore pressure dissipation patterns.
- Calculate compression index Cc, pre‑consolidation pressure Pc, etc.
- Export data and generate a test report.
For step‑loading consolidation: Set a load sequence (e.g., 50, 100, 200, 400, 800 kPa); record
displacement and pore pressure over time at each load step.
For specimen preparation only: Use the compaction program to compact layers without performing a
consolidation test.
Summary:The BTU-CSA-3 is a multi‑functional specimen preparation and
testing system (multi‑functional consolidation apparatus) that
integrates homogeneous specimen preparation with various
consolidation tests. It features a large specimen size
(Ø300×600 mm), axial load up to 30 kN, stroke of 600 mm, and
supports step loading, CRS, CRL, and real‑time multi‑position pore
pressure measurement. Control accuracy is ±0.1% FS, with fully
automatic servo closed‑loop control. It is suitable for studying
consolidation characteristics of coarse‑grained soils, rockfill,
and large specimens, as well as preparing homogeneous specimens.
Selection should consider the required load capacity, specimen
size, and need for multi‑position pore pressure measurement. For
routine small‑size consolidation tests, a smaller consolidometer
may be more cost‑effective.