On April 18, the authority of Chuong My district of Hanoi began to fix the giant sinkhole that was attracted attention from the public. According to the People's Committee of Chuong My district, the entire fixing process would be carried out according to recommendations given by scientists. In terms of time, this could not be done in 1 or 2 days.
Previously, the authority has inspected, surveyed, and measured to assess the cause and find solutions to fix the sinkhole.
The Vietnam Institute of Irrigation Science proposes a 6-step solution. Specifically: Step 1, clean up the area; Step 2, fill the sinkhole with suitable materials, the bottom is expected to be lined with a layer of pit rock with a thickness of 1 meter; Step 3, drill holes to pour mortar and cement. A combination of 200kg of cement and 50kg of bentonite will be used to fill the voids around the subsidence area and harden it; Step 4, spread the reinforced geotextile with 2 layers of above material to fill the sinkhole, with the expected strength of 150kN/m, proceed to anchor the fabric head as specified; Step 5, return the drainage ditch and pavement layers to their original state; Step 6, conduct load testing and post-processing monitoring.
According to the authority of Quang Be commune in Chuong My district, Hanoi, on April 6, a family on the side of the provincial road 419 drilled a well. At 4 p.m. on the same day, after many loud noises, the drill, lots of bonsai, and an electric pole fell into a hole in the ground.
At first, the hole was just over 3 meters wide. But by the evening it was more than 12 meters wide and over 4 meters deep. Facing this situation, the authority had to relocate 12 households around the sinkhole to ensure safety.
On April 17, after prolonged heavy rain, the area of the sinkhole continued to expand, reaching the middle of provincial road 419./.
