UCON Structures LLP was entrusted with the Design & Build contract for executing a diaphragm wall as part of the Water Resources Department’s initiative to strengthen the periphery of Cholavaram Lake in Ponneri, Tamil Nadu. The 600mm thick diaphragm wall was designed and constructed to provide structural stability and prevent seepage, contributing to long-term water retention and embankment protection.
The scope of work involved detailed geotechnical assessment, design of the diaphragm wall, and full execution – comprising area leveling, trenching, grabbing, and concreting. The execution required a high degree of precision due to the nature of the terrain and environmental considerations related to working near a sensitive water body.
Site Challenges at Cholavaram Lake
Despite appearing straightforward, this lakeside infrastructure posed unique technical and environmental challenges.
1. Close to Cholavaram Lake
The construction area was located right along the edge of Cholavaram Lake. This raised concerns about water entering the work zone during trenching and concreting. Extra care was needed to prevent water seepage and avoid disturbing the natural surroundings.
2. Uneven and Soft Soil
The soil conditions varied across the site. Some areas had soft or loose soil, which made it harder to dig the trenches for the diaphragm wall. Proper support was needed to keep the trenches stable before pouring concrete.
3. Risk of Flooding During Monsoon
The region is prone to heavy rains during the monsoon season. There was a possibility of water accumulation and flooding at the site, so the wall design had to account for these conditions and provide long-term protection.
4. Curved Alignment of the Wall
The diaphragm wall had to be constructed along a curved path following the lake embankment. Maintaining accuracy in layout, trench cutting, and concrete placement along this curve added complexity to the work.
Key Construction Methods and Approaches
Tailored Wall Design for Water Control and Stability
A 600mm thick diaphragm wall was constructed to act as a water barrier and retain the surrounding soil. Its depth and reinforcement were planned based on local soil conditions and the changing water levels of the lake.
Slurry Trench Method with Grab Excavation
Hydraulic grabs were used to dig trench panels accurately. Slurry was added during excavation to support the trench walls and prevent collapse until concreting was done.
General Concreting of Panels
Concrete was placed into the trench panels in a controlled manner to form strong, uniform wall sections. Care was taken to maintain consistent quality and proper bonding between panels.
Step-Wise Execution Sequence at Cholavaram Lake
- Site Preparation and Guide Wall Construction
- Equipment was mobilized, vegetation cleared, and the ground leveled.
- Concrete guide walls were constructed to help maintain trench alignment and verticality during excavation.
- Grabbing Operations with Slurry Support
- Trench panels were excavated using hydraulic grabs.
- Bentonite slurry was used simultaneously to support the trench walls and prevent collapse.
- General Concreting of Panels
- Concrete was poured directly into the excavated trench panels.
- Each pour was carefully monitored for volume and consistency to ensure proper filing.
The successful completion of the diaphragm wall at Cholavaram Lake has strengthened a key section of the lake’s boundary. Serving as both a retention system and a hydraulic barrier, the wall is designed to withstand seasonal fluctuations in water level and the resulting lateral pressures.
This project demonstrates UCON Structures LLP’s expertise in combining design proficiency, geotechnical understanding, and construction capabilities to deliver complex diaphragm wall solutions. “Their ability to manage site challenges and ensure precision in every stage reflects the company’s commitment to quality and reliable project execution.
For more details;
UCON PT Structural System Private Limited
No 45, 5th street, Padmanaba Nagar, Adyar, Chennai 600020.
Phone: +91-44 244 68 001/2/3
Email: info@uconpt.com
Website: www.uconpt.com