Erdal Akyol

Geotechnical land suitability assessment using spatial multi-criteria decision analysis

Decision making is a thought-provoking issue in complex engineering problems, and it contains many parameters and alternatives inherently. Multi-criteria decision analysis (MCDA) is a common method to solve the problems involving many uncertainties, and it is employed here for answering some geotechnical issues. Soil type, underground water table (UWT), standard penetration test (SPT) (N) blow numbers, and shear wave velocity (Vs) have been used to sort out the settlement suitability of the municipal area by means of MCDA and geographic information systems (GISs). Each data set was classified into 10 groups and graded based on it. A soil classification map was constructed using Voronoi cells. The Kriging interpolation method was employed to draw the other maps. The study area was allocated into five zones ranging from very favorable to very unfavorable. The very favorable and favorable zones are southern, southwestern, and northern parts of the study area. Firm units with high bearing capacity are outcropped on these areas. Moreover, the UWT is deep enough to interact with structures. On the contrary, the very unfavorable and unfavorable zones are located around the central part of the study area where the altitude is very low. Therefore, the soils have higher fine contents which commonly have low bearing capacity and exhibit high ground amplification when they are encountered with UWT. The faults and creeks, crossed the study area, were enclosed and marked as very unfavorable. It is because of the Turkish infrastructure regulations against flooding and ground rupture risks. The moderate zones fall within the best and the worst zones. The results prove that the spatial multi-criteria decision analysis (SMCDA) descriptions match the perception of the geotechnical assessments. The study has verified that the method can be employed successfully in the geotechnical microzoning studies.

Evaluations on the relation of RC building damages with structural parameters after May 19, 2011 Simav (Turkey) earthquake

Abstract An earthquake has struck Simav, Kutahya, located in the western part of Turkey on May 19, 2011. This paper focuses on the evaluation of the regional damage data and detailed investigation on a set of selected reinforced concrete buildings in Simav county center. The soil properties in Simav are examined in detail using multi-channel analysis of surface wave measurements, boreholes and laboratory test data. The damages are observed to be independent of soil conditions being hilly or plain, both in regional and Simav county center level. However, a slight relation is observed: as the soil period increases, so does the damage. The most damaged buildings are the four story buildings, resembling the case after some other earthquakes in Turkey. Regarding the detailed numerical evaluations on the building set, the properties highly correlated with seismic damage are investigated. Based on the obtained findings, it is concluded that the global building properties may not be enough to establish a strong relation with damage due to the local damages at the structural member level, especially for smaller seismic events.

Environmental Urbanization Assessment Using GIS and Multicriteria Decision Analysis: A Case Study for Denizli (Turkey) Municipal Area

In recent years, life quality of the urban areas is a growing interest of civil engineering. Environmental quality is essential to display the position of sustainable development and asserts the corresponding countermeasures to the protection of environment. Urban environmental quality involves multidisciplinary parameters and difficulties to be analyzed. The problem is not only complex but also involves many uncertainties, and decision-making on these issues is a challenging problem which contains many parameters and alternatives inherently. Multicriteria decision analysis (MCDA) is a very prepotent technique to solve that sort of problems, and it guides the users confidence by synthesizing that information. Environmental concerns frequently contain spatial information. Spatial multicriteria decision analysis (SMCDA) that includes Geographic Information System (GIS) is efficient to tackle that type of problems. This study has employed some geographic and urbanization parameters to assess the environmental urbanization quality used by those methods. The study area has been described in five categories: very favorable, favorable, moderate, unfavorable, and very unfavorable. The results are momentous to see the current situation, and they could help to mitigate the related concerns. The study proves that the SMCDA descriptions match the environmental quality perception in the city.

Geological and geotechnical properties of settlement area of Irgilli town (Denizli)

Yerleşim yeri seçimi ve imar planlarında belirleyici olan jeolojik ve jeoteknik çalışmalar, modern kentleşmenin ilk ve en temel aşamalarından birisidir. İmar amaçlı mikrobölgeleme çalışmaları güvenli bir çevre ve sürdürülebilir bir kalkınma için önemlidir. Bu kapsamda Irgıllı Beldesi’nin (Denizli) yerleşime uygunluğu araştırılmıştır. İnceleme alanı, Işıklı Gölü’nün güney kıyısındaki ovada alüvyonal birimler üzerinde bulunmaktadır. Ova, sismik bakımdan aktif kenar fayları ile çevrelenmiştir. İnceleme alanında çeşitli jeoteknik deneyler ile hidrojeolojik çalışmalar yapılmış, elde edilen veriler ışığında inceleme alanı yerleşime uygunluk özellikleri bakımından sınıflandırılmıştır. Elde edilen bulgular ışığında, inceleme alanı içinde kuzeyden güneye doğru daha uygun yerleşim alanı özellikleri belirlenmiştir. Geological and geotechnical studies, decisive on land use and development plans, are the basic stage of a modern urbanization. Microzonation studies for development plans are crucial for safe environment and sustainable development. This study is focused on settlement suitability of Irgıllı (Denizli) Municipal area. The area is on an alluvium plain where is located on south of Lake Işıklı and surrounded by active fault lines. Some geotechnical tests and hydrogeological studies have been performed and the area was classified in terms of settlement characteristics. According to results of this study, it is determined that the southern part of the area is more suitable to settlement than the northern part.

Yer radarı kullanılarak trüf mantarının bulunması

Honaz Dagi (Denizli-GB Turkiye) iliman ve nemli bir iklime sahiptir ve bu alanda zengin bir flora olusmustur. Bunun dogal bir sonucu olarak, calisma alaninda yukselen bir ekonomik deger olan zengin bir mantar potansiyeli sunmaktadir. Son yillarda, Yer Radari (GPR) sig yeralti kesif icin oldukca modern, etkin ve yaygin olarak kullanilan bir Jeofizik tekniktir. GPR sisteminin 250 Hz anteni ile Honaz Dagi bolgesinde mantar yumrularini izlemek icin kullanilmistir. Mantar sinyallerinin GPR yansimalarini aydinlatmak icin, mantar mineral bilesimi analiz edilmistir. Mantar icindeki K, Na, Ca, Mg, Fe, Al, P, S, Si, Cl minerallerin yuzdeleri, toprak icindeki minerallerden onemli olcude farkli idi. Element bilesimi icindeki bu fark, sinyallerin yansimasinda farklilik seklinde gorunmektedir. Mantarlar profiler boyunca, calisma sirasinda tespit edilmistir. Gozlenen GPR verileri uzerindeki mantar yerleri, fiziksel kazi ile teyit edilmistir. Bu calisma sayesinde, jeofizik yonteminin etkili bir sekilde toprak altindaki dogal mantarlari tespit etmek icin kullanilabilir oldugunu onermektedir.Honaz Mountain (Denizli-SW Turkey) has a mild and humid climate and it produces a rich flora in the area. As a natural consequence thereof, the study area offers a rich mushroom potential that is a rising economic value. In recent years, Ground Penetration Radar (GPR) is a relatively modern and effective and widely utilized technique for shallow subsurface exploration. GPR with 250 Hz antenna was employed to trace the tubers in Honaz Mountain area. To elucidate how the mushroom can reflect the signals, mineral composition of the mushrooms has been analysed. Percentage of K, Na, Ca, Mg, Fe, Al, P, S, Si, Cl minerals were significantly different from that of earth. This difference in element composition seems to cause the reflection of the signals. A large number of mushroom grooving areas have been detected during the study. The observed GPR data have been confirmed by the physical excavation. The study proposes that this method can be effectively employed to detect the natural mushrooms in the ground .

Coğrafi Bilgi Sistemi ve Analitik Hiyerarşi Süreci ile Jeoteknik Yerleşim Alanı Uygunluğunun Belirlenmesi

Bilginin ve tecrubenin cozume dâhil edildigi cok kriterli karar verme teknigi (CKKVT) cok sayida belirsizlik ve parametre iceren problemlerin cozumunde yaygin olarak kullanilmaktadir. Bu problemler konumsal bilgiler icerdiginde cografi bilgi sistemi (CBS) destekli cozumler karar surecinin dogrulugunu ve hizini arttirmaktadir. CKKV tekniklerinden birisi olan Analitik Hiyerarsi Sureci (AHP) jeoteknik problemlerin cozumunde de kullanilabilir. Bu calismada yaygin ve etkin olarak kullanilan jeoteknik parametreler olarak zemin turu, SPT darbe sayisi, kesme dalgasi hizi ve yeralti su seviyesi kriterleri dikkate alinarak ve CBS ile Denizli Belediyesi yerlesim alani inceleme alaninin jeoteknik acidan yerlesime uygunlugu analiz edilmistir. CKKVT sonuclari yazarlarin jeoteknik gozlem ve deneyim ile elde edilen sonuclara uyumlu cikmistir. Kriterler dogru degerlendirildiginde, yontem jeoteknik amacli mikro bolgelendirme calismalarinda basarili bir sekilde kullanilabilir.

Adverse Effects of Soil Grouting on Sandy Soils

Uncontrolled growing of construction industry in Turkey has caused a large number of buildings were constructed without the benefit of sufficient engineering supervision. These phenomena have contributed to the increase in the number of seismically weak buildings. After the Great Marmara Earthquake seismic performances of the existing structures have been inspected and some of them fortified. In this context, an existing building foundation, built on a problematic soil and located in Denizli where is in high seismic risk area, has been strengthened by cement injection. Grouting holes up to 7 m in depth from the basement level were used in 45 points. The injection has created a less permeable barrier, acts like an underground dam. This barrier has caused rising of the underground water table around the recharge area of the foundation. The raised underground water has increased hydraulic gradient and hydraulic pressure. Then, the basement floor has arched up to 12 cm and underground water has risen up to 30 cm high after one year of the injection practice. In this study, hydrogeological characteristics of the soil structural analysis have been evaluated and some solutions suggested remedying the problem. It should be kept in mind as injection practice is employed in aquifers.

Seismic Microzonation for Denizli Metropolitan Area, Turkey

This study presents microzonation of the Denizli city center, is about 225 km2. It is mainly rely on t seismic velocities of the tested soil. For seismic microzonation area of has been selected as the study area. Seismic refraction methods have been used to generate two-dimensional profiles at 310 locations. These p and s wave velocities are used to estimate boundaries of the velocities at every 2 and 5 m intervals up to a depth of 60 m. The results are satisfactory for urban planning and it can successfully be used in urban areas. The municipal authority may be considered to use the results for land use studies.

District Selection for Settlement Suitability Using Geographical Information Systems and Multi Criteria Decision Analysis: Denizli Case

Anahtar kelimeler “CBS”; “Konumsal Analiz”; “Çok Kriterli Karar Verme”; “Mikro Bölgelendirme”; “Jeoteknik”; “Denizli” Özet Bilginin olduğu kadar tecrübenin de büyük önemi olan çok kriterli karar verme tekniği (ÇKKVT) birçok belirsizlik ve parametre içeren problemlerin çözümünde yaygın olarak kullanılmaktadır. Bu problemler konumsal bilgiler içerdiğinde CBS destekli çözümler karar sürecinin doğruluğunu ve hızını arttırmaktadır. ÇKKV tekniklerinden birisi olan ağırlıklandırılmış puanlama jeoteknik problemlerin çözümünde de kullanılabilir. Bu çalışmada Denizli Belediyesi sınırları içerisinde kalan mahallelerin jeoteknik açıdan uygunluğu değerlendirilmiştir. Değerlendirmede jeoteknik parametre olarak zemin türü, SPT darbe sayısı, kesme dalgası hızı ve yeraltı su seviyesi kullanılmış ve sonuçlar CBS ile analiz edilmiştir. ÇKKVT sonuçları jeoteknik gözlem ve deneyim ile elde sonuçlara uyumlu çıkmıştır. Kriterler doğru değerlendirildiğinde, yöntem jeoteknik amaçlı mikro bölgelendirme çalışmalarında başarılı bir şekilde kullanılabilir.