The National Coordinator for Disaster Reduction (Conred) shared three reports regarding the situation in the sinking at kilometer 15 of the route and to the Pacific and that shows how the problem has grown.
The reports for June 15, 16 and 18 are called Assessing Emergencies and the first recalls what happened on June 13 just last, when personnel from the metropolitan region received reports regarding rumblings in zones 2, 5 and 6 of Villa Nueva and later cracking and subsidence at km 15.
At the time of the field visit on June 15, the Conred identified an undermining with dimensions of 4 x 12 meters and a depth of approximately 6 meters, with respect to the level of the asphalt layer, which covered a central lane of CA09 , heading south.
They observed cracks on both roads of the CA-09 South, covering a distance of approximately 66 linear meters; This problem was attributed to the normal behavior of the local fault system and, in the case of drainage, the possibility of the collapse of a section of the pluvial drainage collector.
Images shared by Conred show what the behavior was like for June 15. As of that date, the cracks observed on both lanes of CA-09 South continued in the part of the property where Empresa Belca Guatemala, SA is located, specifically affecting the entrance lane, the green area and the space where equipment is located. Likewise, said crack extended into a vacant lot located at the rear of the Construferre Company.
On that occasion, the cracks and undermining observed on the lanes that make up CA09 (in both directions), as well as on part of the land belonging to the companies Belca Guatemala, SA and Construferre, can be attributed to the normal behavior of the local fault system, triggered by the 1976 earthquake.
According to the field report, it is possible to identify the area where the cracks appear, likewise, the outline of guidelines taken from aerial photography that have a displacement from north to south was observed. These are normal displacement faults where the upper block descends with respect to the lower block.
The report explains that structurally, the area is dominated by the regional fault system in a north-south direction, which manifests itself with a normal vertical behavior and which is a graben part of Guatemala City.
Through the data taken from the cracking direction, a rosette diagram analysis was carried out, identifying that these cracks have a course similar to that of the fault system that is in a north-south direction.
Conclusions of the first report
Conred’s conclusions as of June 15 were that the natural behavior of the existing fault system in the area associated with the Mixco fault, which generated a north-south oriented crack, which reached a distance of approximately 66 linear meters, crossing CA-09 Sur (both lanes) and part of two lands adjoining said road section.
No debris from elements that make up the drainage system that have been damaged was detected in the affected area, nor was there any presence of moisture, but The collapse of any pipe located at a depth outside the evaluated range is not ruled out.
Nor did they find a combination of factors of natural origin, as well as anthropic events (possible existence of a drainage system and age of the materials that make up said systems), circumstances that can accelerate the processes of erosion and particle transport, which would leave an area unstable groundwater, significantly affecting assets and existing infrastructure.
How the situation got worse
On June 16, Conred shared another report showing how the situation has worsened.
It was observed that the length of the cracks increased In relation to those reported on June 14, displacements and deformations were also observed with respect to the level of the grade of the asphalt layer, which cover the width of the lane in the north direction of CA-09.
crack increased length
It was observed that the crack related to the normal behavior of the local fault system increased its length, in a distance of approximately 100 linear meters, compared to what was detected the day before, which can be seen inside the parking area of a company in Villa Nueva.
The cracks continued on the green area that is in the return lane towards CA-9 and the overpass continuing towards the return cloverleaf and continue towards a farm.
Also read: Sinking in Villa Nueva: What is the support that United States engineers will give Guatemala to place the Bailey Bridge
Conred observed that maintenance work had been carried out previously in the well near the sinking area, it is observed that there is accumulation of sediment, indicating that there is stagnation of water and infiltration at the point and possible deterioration in the pavement base.
The conclusions warn that the crack keeps increasing in length and that the combination of factors of natural origin can accelerate the erosion process, would leave an unstable underground area that would affect road assets and infrastructure and basic services.
Install technical table
Also install a technical table to determine in more detail the origin and causes of the sinking, how to propose solutions.
While the Municipality of Villa Nueva recommends continuing with the explorations in the drainage system and making the evaluations and repairs.
Undermining increased dimensions
In the June 18 report, It stands out that derived from the rains of June 17 by tropical storm Celia, it was observed that the undermining increased its dimensions to 16 x 25 meters and with a depth of 12.
Also read: Sinking in Villa Nueva: Filling in a hole on the route to the Pacific could have cost Q1.3 million
This shows instability, due to the characteristics of the soil and its high level of saturation (probably derived from the collapse of the drainage system), a situation that increases the level of structural vulnerability of the infrastructure. mainly from the Enrique Tejada Wyld overpass.
Reports show how the problem has been increasing in the area of the sinking in Villa Nueva.