architecture+engineering: Digital Portfolio

In this section of the blog, failure cases that took place in Turkey will be discussed and analyzed.

1. 3 workers lost their lives in the collapse that occurred in the felspar mine in the Sarıkaya District of Muğla's Milas district.

3 people lost their lives as a result of the rock-type material on the upper part of the slope, which opened in one level, slipped into the quarry and fell on the construction machines and workers. At around 10.30 am on Monday, February 18, at the feldspar mining site, which operates on open land, a giant piece of rock fell over the construction equipment. While the rock blocks were being removed from the site, in the dent that was stated to have occurred as a result of the displacement of the rocks; excavator operators stuck under rock.

As can be seen from the photographs taken inside the quarry, there is only one level in the open pit area and its height is approximately 3540 meters. It is known that the rocks located in the region where the accident took place (where production takes place) are fractured, cracked and exposed to tectonism. It is seen that the slip occurred in the slope mirrors, which were opened without determining the fracture and crack system, which is controlled by the regional tectonic structure and which is important in the slope stability analyses, caused the accident in question. For this reason, it is of great importance to perform slope analyzes based on parameters such as regional tectonic regime, fracture and crack system, engineering properties of rocks, slope angle and geometry during any work done or/or to be done.

It is inevitable that similar accidents will occur as long as there are safety measures as simple as the 'Caution Dentification Hazard' written on the rock, which was taken from the region and written with spray paint on the rock at the site of the accident.

Definitions of warning signs and triggers are given below:

- Geotechnical indicator is a sign, a state or a contributing factor that points out or suggests that the rock mass or geotechnical structure may be prone to structural failure. In general, natural features like faults, folds, change in mechanical properties, etc, are indicators of damage or possible future failure.

- Geotechnical precursor is a behaviour that suggests that the rock mass or geotechnical structure has been damaged and that may precede possible failure. Precursors may include ground movement, crack opening or acoustic emissions.

- Trigger is an external occurrence that initiates or brings about structural damage or failure. Triggers include rainfalls, blasting, seismic events, etc.

2. Retaning Wall Collapsed During Foundation Excavations, the Building Next to the Construction Site Evacuated.

On 25 February 2021, a construction site in Artvin Borçka had an incident concerning retaining walls. The excavator that was digging the site was under the wreckage, but the operator managed to get out of the machine unharmed. Fortunately, no other person was injured. The building which had its retaining walls collapsed was evacuated for security reasons. Rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides are called retaining walls.

The most common reasons for failure are,

lack of proper reinforcement
improper drainage behind the wall
foundation footing problems
settlement expansion of the soil
overloading the wall
construction errors or other design errors.

For this case, the problem was caused by the excavator because they should have calculated the foundation that the retaining wall was settled in. At this point, they should either demolish the building or they should reinforce the wall with a curtain of piles of curtain grouting.