An Investigation on the Deformations Occurring on the Floors of Historical Buildings – Buildings; It is a place that appeals to the various needs of people since ancient times. People used houses for shelter, roads and bridges to gain access to a place. As time passed, they built hospitals, places of worship, and schools. In this context, historical buildings are the visual representatives of cultures. Indeed, Victor Hugo said, “Those who know how to look can discern the spirit of a century and the facial expression of a king even in the knocker of a door.” He emphasized the importance of historical buildings.
In order to find a solution to the problems, it is important to find out what the root of the problem is in order not to repeat the problem. The deformations and distortions that occur are divided into sub-headings according to their sources.
Historical buildings are structures built with the masonry technique. Since there are no skeletal systems, all walls take on the role of load-bearing curtains. Although they are resistant to compressive stresses due to their high structural weight, they generally have difficulty in meeting tensile stresses. Because of all these, deformations may occur in our country, which is located on active fault lines, due to horizontal forces such as earthquakes.
An Investigation on the Deformations Occurring on the Floors of Historical Buildings
In regions with irregular precipitation regime due to climate, floods cause serious damage to stone belts. Settling damages on the ground can affect the entire system and cause cracks. Effects that can lead to deterioration due to acid rain and humidity and even fragment rupture have been observed.
In addition to all these effects, faulty repairs, wars and fires caused by people cause deformation and deterioration of historical buildings. In this article, the deformations and deteriorations caused by the ground will be examined in detail in the light of literature reviews.
Deformations and Distortions Caused by the Ground
If we collect the ground-related damages seen in historical buildings in six groups, these are; settlements, decompositions, swelling and swelling, fragmentation, cracks and slips (Köseoğlu, 1896).
The cause of the damages that occur in the form of both decomposition and swelling and swelling are the physical and chemical reactions occurring in the building material. For example, the chemical effect that will cause decomposition may be the sulfate effect caused by the external environment, while the physical effect may be freezing and thawing (Namlı, 2001).
While examining the effects that cause fragment rupture, factors such as atmosphere effect, internal temperature rise, chemical reactions that may cause damage should be considered, as well as the effects of earthquakes and similar shock waves (Namlı, 2001).
Cracks originating from the ground usually occur as a result of settlements. The main causes of foundation settlements are; Changes in the groundwater level, changes in the carrier system, excavations around the building, insufficient drainage, decay of piles, earthquake and environmental (traffic etc.) effects can be counted.
Change of Groundwater Level
As the groundwater level decreases, the pore water pressure decreases. Therefore, the weight of the soil particles floating in the water increases and settlement begins again with the additional loads on the underlying soil. As a result of the decrease in the underground water level, shrinkage cracks may also occur due to the drying of the ground. As the groundwater level rises, the soil becomes saturated and the bearing capacity decreases. Because of this, settlements can cause deformations when they exceed a certain limit.
Changes in the carrier system can cause the load system to change and the foundation to be forced in different ways. As a result of the change of direction of the river bed, scours occur in the foundations of the bridges. As a result of the growth of these scours, some settlements occur on the bridges. These settlements can cause cracks and fractures (Ural et al, 2007).
Wooden piles are used in the foundations of historical buildings. Wooden stakes can rot when exposed to air. As a result of rotting, settlements may occur on the ground.
Excavations Around the Building
Excavations for different purposes around the building may cause landslides and slides. The voids formed can cause deformations as they will disrupt the balance of the foundation and the ground.
Liquefaction is the temporary loss of strength of the soil by the shock effect of dynamic waves such as earthquake waves. It occurs on sandy-silty soils. It can cause damage to historical buildings.
In this article, ground-based causes of deformation and deterioration are examined. As a result of the researches, the importance of strengthening historical buildings with the right materials and techniques, regardless of the reason, has been understood once again. But here, the engineer must first know the source of the damage to the structure.