Geotechnical Laboratory Triaxial Testing In Bangladesh

Introduction of Triaxial Test

Triaxial testing is a fundamental procedure in soil mechanics and geotechnical engineering used to assess the mechanical properties of soil under various stress conditions. This test is crucial for understanding soil behavior under simulated in-situ conditions, and its global application spans multiple fields including construction, mining, and environmental engineering. Standard for this test is BS: 1377 parts 7 and 8, ASTM D2850, D4767, and D2166, AS AS1289, DIN 18137, GOST 12248-96. 

Triaxial testing is a critical technique in geotechnical engineering used globally to assess soil behavior under simulated stress conditions. Recent advancements include digital instrumentation, automation, and sophisticated software for enhanced accuracy and efficiency. This testing is vital across various sectors such as construction, mining, and environmental engineering, where it helps evaluate soil stability and performance. Standardization and rigorous quality control ensure consistent and reliable results, while ongoing research and technological innovations continue to expand its applications. With increasing urbanization and climate change impacts, triaxial testing remains essential for safe and effective engineering solutions.

In Bangladesh, triaxial testing is crucial in geotechnical engineering due to the country's unique soil conditions and high population density. The rapid urbanization and infrastructure development in cities like Dhaka and Chittagong have heightened the need for reliable soil analysis to ensure the stability and safety of buildings, roads, and other structures. Triaxial testing is used to evaluate soil properties such as shear strength and compressibility, which are critical for designing foundations and assessing the risk of soil liquefaction in earthquake-prone areas. Additionally, with the challenges posed by climate change, including increased flooding and riverbank erosion, triaxial testing helps in understanding soil behavior under varying moisture conditions. Although advancements in technology and standards are gradually being adopted, there is still a need for enhanced training, quality control, and modernization of testing facilities to meet the growing demands of infrastructure development and environmental management in Bangladesh. In the case of the feasibility study, most of the mega projects of government entities like LGED, PWD, RHD, DPHE, CITY CORPORATION, RAJUK, WASA, BBA, PORT CITY, POWER PLANT, and others including private projects, construction and development project use triaxial test rapidly for geological classification of soil.

As Iconic Engineering Ltd conducts triaxial testing in Bangladesh, can significantly contribute to the Digital Bangladesh vision by adopting advanced digital technologies, such as automated testing systems and cloud-based data management. Enhancing data integration and analytics will improve accuracy and decision-making in infrastructure projects. By providing precise soil analysis, supporting sustainable engineering solutions, and offering training programs for skill development, you help build a resilient and knowledgeable workforce. Engaging in research and fostering collaborations will drive innovation, while advocating for digital standards will shape industry practices, positioning your company as a key player in the nation's digital transformation.

What is Triaxial Testing?

A typical triaxial test involves confining a cylindrical soil or rock specimen in a pressurized cell to simulate a stress condition and then shearing to failure, in order to determine the shear strength properties of the sample. Most triaxial tests are performed on high-quality undisturbed specimens. The samples normally range although samples considerably larger can be tested with the correct equipment. The test specimen most commonly has a height-to-diameter ratio of 2:1.The sample will usually be saturated, then consolidated, and finally sheared, most commonly only in compression – but extension tests may be undertaken with the correct equipment.

Why We Use Triaxial Testing?

Triaxial tests are one of the most widely performed tests in a geotechnical laboratory. The advantages of the test over other test methods used in the geotechnical laboratory to determine shear strength (such as direct shear) are that specimen drainage can be controlled and pore pressure can be measured. The triaxial test enables parameters such as cohesion (c’), internal angle of friction (φ’) and shear strength to be determined.

The triaxial test can also be used to determine other variables such as stiffness and permeability with the correct equipment.

A list of some of the common engineering issues that triaxial tests can be used for can be seen in

Where is it Usage Triaxial test area?

The Usage Triaxial Test, also known as the Unconfined Compression Test (UCT), is a common geotechnical test used to determine the shear strength of soil. This test is typically conducted in laboratory settings rather than specific geographic locations. Geotechnical engineering laboratories around the world perform these tests as part of soil mechanics studies.

In Bangladesh, the Usage Triaxial Test, which is a type of geotechnical test used to determine soil properties such as shear strength and consolidation characteristics, would typically be conducted in geotechnical engineering laboratories. These laboratories are often associated with universities, research institutions, or consulting firms specializing in geotechnical engineering.

Types of Triaxial Testing:

• CD Triaxial – Consolidated Drained triaxial
• CU Triaxial – Consolidated Undrained triaxial
• UU Triaxial – Unconsolidated Undrained

Consolidated Drained (CD) Triaxial Test

The specimen is fully consolidated and then it is sheared slowly to allow the generated pore water pressure to be fully dissipated. This requires at least 1 day for the consolidation process for conducting a drained shear test. Let us assume that a clay specimen is prepared with enough water to have the water content above its liquid limit, and then the consolidated drained test is performed. For nearly zero consolidation pressure, the strength of the specimen is nearly equal to zero since the specimen’s initial water content was above the liquid limit. With a small consolidation pressure, the specimen gains some strength due to the consolidation process. During the shear, it also gains some more strength due to the drainage of water. With higher consolidation pressure, it gains more strength due to its higher reduction in water content through the consolidation and drained shear processes.

Consolidated Undrained (CU) Triaxial Test

This is the most commonly used triaxial shear test practice in Bangladesh. The specimen is the first fully consolidated in the triaxial cell. In a 'consolidated undrained' triaxial test the sample is not allowed to be drained. The shear characteristics carve is measured under undrained conditions and the sample is assumed to be fully saturated condition.

Unconsolidated Undrained (UU) Test

The simplest triaxial compression test would be a UU test. During sample preparation time, the specimen is not allowed any consolidation process. Shortly after the specimen is placed in the chamber, the confining stress is applied through the specimen membrane and sheared under undrained conditions; that is, the drainage valve is kept closed, and it is sheared in a short time. During the sample preparation and shearing processes, there will be no escape of the pore water from the specimen; thus, no change in the water content of the specimen will take place. UU triaxial tests commonly do not have a saturation or consolidation stage performed; the test normally only consists of a shear stage. UU triaxial tests are quick tests, taking under 30 minutes to perform. The CU and CD triaxial tests take significantly longer to perform and can take weeks or even months to complete. The CD Triaxial commonly has the longest test duration

Test Procedure in Triaxial Test

Sample Preparation Soil Sample Collection: The soil specimen should be undisturbed and representative of the natural conditions at the test site.

Sample Trimming: Trim the soil sample to the desired size and shape using a trimming tool. The shape typically resembles a cylindrical specimen, which fits into the triaxial cell.

Ensure that the trimmed sample has flat and parallel ends for proper seating within the triaxial cell.

Sample Assembly:

Advantages of an ICONIC ENGINEERING Triaxial System

• Tests run 24 hours a day 7 days a week
• The average time for a test to be completed is significantly reduced
• Can be monitored and controlled remotely
• Limited staff supervision required
• Less staff required to perform more tests
• Increased quality of results and minimize human error
• Easier to maintain
• Easier to calibrate
• No compressed air required
• The software provides updates on testing via email
• Expertise the report generation
• A specialized person can analyze data

Contributing to Smart Bangladesh Mission through Triaxial Test

As Iconic Engineering Ltd conducts triaxial testing in Bangladesh, your role in advancing the vision of a "Digital Bangladesh" can be pivotal in several ways:

1. Implementing Digital Technologies:

Automated Testing Systems: Invest in and deploy advanced digital triaxial testing equipment that offers automated data acquisition and analysis. This will enhance the accuracy and efficiency of your testing processes.

Data Integration: Develop systems for real-time data collection and integration. This includes using digital platforms for seamless data sharing and analysis, which can improve decision-making and project management.

2. Enhancing Data Management:

Cloud-Based Solutions: Utilize cloud-based data storage and management solutions to ensure secure and accessible data. This facilitates collaboration with other stakeholders and makes data available for further research and analysis.

Big Data Analytics: Leverage big data analytics to interpret large volumes of test data, uncovering patterns and insights that can inform better engineering practices and policies.

3. Supporting Infrastructure Development:

Precision Engineering: Provide accurate and detailed soil analysis to support the design and construction of infrastructure projects, ensuring safety and stability. This aligns with the national goals of building resilient and reliable infrastructure.

Sustainable Solutions: Use your data to support the development of sustainable engineering solutions that can mitigate the impacts of climate change and environmental degradation.

4. Training and Capacity Building:

Skill Development: Offer training programs for engineers and technicians on the latest digital triaxial testing technologies and methodologies. This helps build a skilled workforce capable of contributing to the digital transformation in engineering.

Knowledge Sharing: Share your expertise and findings with academic and research institutions, contributing to the overall knowledge base and fostering innovation in the field.

5. Promoting Innovation:

Research and Development: Engage in research and development projects that explore new digital methodologies and technologies for triaxial testing. This can position your company as a leader in engineering innovation in Bangladesh.

Collaborations: Partner with tech companies and research organizations to integrate cutting-edge technologies into your testing processes, supporting the broader goals of digital advancement.

6. Supporting Policy and Standards:

Advocacy: Advocate for the adoption of digital standards and best practices in geotechnical testing at both national and local levels. This can help shape policies that promote technological advancement in the industry.

In Bangladesh main users of this survey are LGED, RHD, BBA, DMTCL, DNCC, DSCC, WASA, City Corporation, RAJUK, DPHE, CAAB, PWD, Bangladesh Railway Department, DESCO, NESCO, EGCB, PGCB, BPDB, and other private industry like a construction company, real state, and other contractors.

Consolidation testing is essential because it helps to assess the soil's compressibility and its response to applied loads over time. This information is critical for geotechnical engineers when designing foundations, evaluating settlement potential, and understanding soil behavior in various engineering applications. If there are specific aspects of consolidation testing or triaxial testing that you would like to delve into further, feel free to ask for more details!