Author: Engr. Muhammad Adeel Khan
Profession: Chartered Structural Engineer
Contact: +92 342 9632484
YouTube: @muhammadadeelkhanofficial
Reasons for the House Collapse in Potha Bensi Near Mangla Dam | Mirpur AJK
Recently, a tragic series of house collapses in Potha Bensi, near Mangla Dam (Mirpur AJK), has raised serious concerns about construction practices in the region. As a Professional/Chartered Structural Engineer, I visited the area and analysed the technical causes behind these failures. It was observed that entire structures had sunk or tilted, indicating severe ground instability and soil failure. The situation highlights the urgent need for implementing proper geotechnical, structural, and drainage standards in all new constructions near water bodies like Mangla Dam.
Technical Causes of Collapse
- Absence of Soil Investigation Prior to Construction: One of the primary reasons for these collapses is the lack of soil testing and geotechnical investigation before starting construction. The areas surrounding Mangla Dam have high groundwater tables and loose, water-saturated soil layers, which lose strength under vibration or load. Without proper soil bearing capacity tests, structures are founded on weak ground, leading to sudden settlements and collapse.
- Inadequate Water Drainage System. Continuous seepage and water pressure from the Mangla reservoir affect the soil stability.
Due to poor drainage systems, rainwater and seepage accumulate under foundations, creating liquefaction during heavy rainfall or vibration. This causes the soil to lose its. - Lack of Proper Retaining Wall Design. Many properties in the affected area are built on slopes or cuttings, yet retaining walls are either absent or inadequately designed. A retaining wall is critical to resist lateral earth pressure and prevent soil sliding. In these cases, walls were constructed without reinforcement design approval or drainage layers, which caused backfill saturation and eventual failure.
- Vibrations and Earthquake Sensitivity. Mirpur is located in a highly seismic zone, where both earthquake vibrations and heavy construction machinery can trigger soil movement. When vibration occurs, pore water pressure in the soil increases — and if the soil is already weak, it loses strength and behaves like a fluid, a process known as soil liquefaction. This is a key factor behind the rapid and large-scale structural failures observed.
Recommended Remedies:
To prevent future collapses, it is crucial that authorities and developers adopt professional design and
supervision practices:
- Establishment of a Structural Design Wing
In MDA, MDHA, and MCM Mirpur AJK to review, verify, and approve all structural designs before
construction. - Implementation of Approved Structural Designs
Mandatory on-site supervision and monitoring during construction to ensure that approved structural drawings are implemented faithfully. - Adoption of Strong Foundation Systems
Use of Piles, Raft Foundations with Anchors, or Rock Anchoring Systems in areas with poor soil strength or high water tables. - Soil Investigation & Water Drainage Design
Every new project must include a comprehensive soil test and a proper sub-surface drainage system to divert water away from foundations. - Retaining Wall Engineering & Supervision
Retaining walls must be designed and supervised by qualified structural engineers, using reinforced concrete, weep holes, and filter layers.
Conclusion
The collapses in Potha Bensi serve as a serious warning for engineers, builders, and local authorities in Mirpur and surrounding regions.
Building near large water bodies like Mangla Dam requires special geotechnical consideration, structural design accuracy, and strict site supervision. Only through engineering discipline, regulatory enforcement, and professional accountability can we ensure the safety of our communities and the sustainability of construction in Azad Kashmir.