Engineering Geology

ÖZET Bilindiği üzere, yüzey faylanmasına direnecek bir yapı tasarlamak ekonomik, mühendislik ve mimari açıdan çok da pratik değildir. Bu nedenle yüzey faylanmasına ilişkin tehlike açısından bir bölgenin değerlendirilmesi zor ve hassas bir yöntemdir. Bir başka anlatımla, bir diri fay üzerinde bir yapı yapıldığı zaman, o yapının yeri değiştirilmediği sürece, olası faylanma sonucu oluşacak tehlikeyi azaltmak mümkün görülmemektedir. Bu çalışma, yüzey faylanmasından ileri gelen tehlikeleri azaltmak amacıyla, diri fayların etrafındaki yapılaşmalarla ilgili esasları düzenlemek ve ülkeye Türkiye Fay Yasası adı altında yeni bir yasal süreci kazandırmayı amaçlamaktadır. Dünyada ve ülkemizde yapıların yer sarsıntısına karşı dayanıklı olmasını sağlayacak tasarım ölçütleri geliştirilmiştir. Örneğin, dünyanın 28 ülkesinde Depreme Dayanıklı Yapı Yönetmelikleri bulunmaktadır. Ancak bunların hiç biri diri faylar yakınında yer alan yapılarla ilgili ölçütler içermemektedir. Bazı yapı yönetmelikleri ve düzenlemeler, diri ve potansiyel diri faylar civarında mevcut ve yapılacak yapılarla ilgili ''tampon bölgeler'' oluşturulmasını ve deprem etkilerini en aza indirgeyecek ölçütlere ilişkin güvenlik amaçlı bazı yasal düzenlemelerin yapılmasını zorunlu kılmaktadır. Tampon bölge oluşturulacak bir diri fay araştırmasının nasıl yapılacağı, hangi yöntemlerin uygulanacağı, inceleme alanında ya da yakın civarında yer alan tehlikeli fayların varlığı ve yerleri, fayların tipleri, mümkünse yüzey yerdeğiştirmelerin miktarı ve tipi, gelecekte olacak faylanmaya ilişkin yüzey yerdeğiştirmeleri ile ilgi düşük, orta, yüksek gibi kategorize edilmesi, tehlikeli faylardan ne kadar uzaklıklarda yapılaşma yapılacağına ilişkin tampon bölgelerinin oluşturulması, ek çalışmalara gereksinim duyulup duyulmadığı ve önerilmiş proje yerine ilişkin kabul edilebilir risk değerlendirilmesi konusunda bilgileri içeren ayrıntılı klavuz bir kitapçık mevcut olmalıdır. Diri faylarla ilgili tüm teknik standart ve kriterler oluşturulduktan sonra, klavuz kitapçıkta verilen teknik bilgiler, politika ve kriterler, bu tür fay araştırmalarının hangi kurum/kuruluş ya da özel sektör tarafından yapılacağı, hangi kurum tarafından denetlenmesi gerektiği, denetleyicilerin vasıfları, denetimin dozu, yerel yönetimlerin yetki ve sorumlulukları, mülk sahiplerinin hakları, itiraz şekli vb. konular hukuksal dile dönüştürülerek, yasa yapıcılar tarafından acilen " Türkiye Fay Yasası " adı altında bir yasa haline getirilmesi ülkemiz için çok büyük önem arz etmektedir. Bu yasal dayanağı esas alarak gerçekleştirilecek çalışmalar sonucunda, son 10 bin yılda deprem üreten diri faylar etrafında oluşturulacak tampon bölgeler yeşil alanlar olarak bırakılarak gelecekte olası büyük depremlerde faylanmadan dolayı yıkılacak binalar olmayacak, can ve mal kaybı önlenmiş olacak, ilerde deprem olması durumunda

Besides precipitation triggered landslides, a major thread from landslides is related to earthquake triggered landslides, which account for the majority of catastrophic landslides. This fact is complicated due to the progressive development of urban areas and infrastructure, the dependency of our society on a functioning infrastructure and an increasing number of endangered objects in the affected areas. Therefore there is a need to improve basic understanding of the technical, financial and social risks posed by earthquakes triggered landslides. Furthermore basic understanding of processes and cascading hazards related to earthquake triggered landslides must be improved. For the past two decades an increasing number of landslide warning systems are developed and applied for general public and industrial purposes. On the other side earthquake triggered landslide warning and monitoring has made very little advances and is still under development. Resent research in the area of sensor network development focus on the application of micro sensors (MEMS) in ad hoc wireless sensor networks operated in an interoperable spatial data infrastructure (SDI) according to the sensor web enablement (SWE) guidelines of the OGC (Open Geospatial Consortium) for real-time monitoring of landslides like the SLEWS – Sensor based Landslide Early Warning System. The SLEWS sensor nodes provide next to motion detection also a 3D acceleration data to evaluate direction and value of the peak acceleration. This information can be used in an event case both to monitor endangered slopes or critical infrastructures and to initiate warnings to trigger e.g. rail or road blocks. Furthermore the data from the sensor network can be provided in real-time for shake or alert maps via standardized interfaces.

ABSTRACT For construction in rock a thorough pre-investigation is important in order to avoid unforeseen conditions which may delay the work. It is crucial to remember the results from this investigation in the further work, and use the experience from the construction to update the geological prognosis and reduce the uncertainties. Different geophysical methods have proved valuable tools in such investigations. In this work the electrical imaging is evaluated with regards to the method's applicability. The evaluation is done qualitatively by comparing the electrical imaging with tunnel documentation from a tunnel in Southern Sweden. By evaluating the result continuously when making the tunnel a more detailed geological prognosis can be compiled and used in the continued work with the tunnel. The parameters used for the comparison are lithology, Q, RQD, weathering and water leakage. The result was that virtually every change in electrical resistivity image coincides with a change in rock conditions. The general trend was that high resistivity corresponded with good quality gneiss whereas low resistivity corresponds to poor quality rock e.g., high weathering, low RQD, low Q and/or several lithological contacts. The intermediate resistivity is often amphibolites or rock with water bearing fractures. The results were supported by in-situ resistivity measurements inside the tunnel and resistivity logging in a core drilling. Geoelectrical imaging proved to give valuable information for a detailed geological model, which could be compiled for a section where the tunnel had not yet been drilled as a help for planning of the continued tunnel work. As is the case other geophysical methods it is clear that for the interpretation of data a priori information about the geological setting is necessary.

Early warning systems are becoming one of the main pillars of disaster prevention in natural hazards
especially where mitigation strategies are not realizable. Therefore, the call for multi-hazard early warning systems and improvement of monitoring of natural hazards is steadily growing. However, data gathering (generation) through sensor integration as well as system independent supply of information from early warning networks are of particular challenge. Because very complex information and warning chains have to be served for, standardization and interoperability plays an important role for all organizations and infrastructures being involved. The SLEWS project investigates the complete information chain, starting from data gathering using wireless sensor networks via information processing and analysis to information retrieval. This is demonstrated for landslides and mass movements. The proposed approach adds especially to the funding target of mobile, cost-reduced and easy deployable measurement systems, as well as the modern information systems under consideration of interoperability and service orientated architecture concepts. The proposed wireless network provides the basis for applying further techniques like sensor fusion, identification of malfunctions or errors. The obtained geodata is processed according to the requirements of particular users and can be provided for use in a local or regional as well as global information structure. Interfaces will be created, which make a mobile and flexible adaptation or integration of geodata possible. Thus, it is ensured that the early warning system reaches the spectrum of potential users and provides a maximum flexibility.

Copyright 2009, Society of Petroleum Engineers This paper was prepared for presentation at the 2009 SPE/EAGE Reservoir Characterization and Simulation Conference held in Abu Dhabi, UAE, 19–21 October 2009. This paper was selected for presentation by an SPE ...

The Tabarak Abad Dam on the river Tabarak, a branch of Atrak river, is located about 25 km of northeast of Quchan city in the northeast of Iran. The dam is now under construction and will be completed in 2002. The Tabarak Abad Dam has been designed as an earthfill dam ...

... According to the results of Prikryl (2001), with increasing porosity UCS decreases logarithmically ... authors gratefully acknowledges the Hungarian Natural Research Foundation support (Grant numbers: OTKA T034603 and OTKA F 043291) and they thank Dr. I. Marek for carrying ...

Digital geoinformation for the surface and subsurface is virtually never integrated in civil engineering projects. Reasons are that the surface information is gathered by different person’s and that the subsurface information is in different formats from the surface information. Likelihood and uncertainty of subsurface models is not quantifiable. To quantify the likelihood and correctness of the subsurface information the civil engineer would have to have full access to the original data, which is not available due to the none integration of the data. In the last 10 years considerable progress has been made in use of geographic information systems but the progress in the integration of data and the addressing of likelihood of subsurface data is limited.

On March 20, 2019, Wednesday, at 09: 34 (TS), a damage-destructive earthquake of Mw 5.5 lasting 11 second at a depth of 9.72 km stroke Ucarı-Yeniköy (Acıpayam, Denizli) region. The earthquake is located between Ucari and Yenikoy, 6.5 km east of the center of Acipayam. From 02 to 20 March 2019, 50 earthquakes ranging from 0.9 <Mw <3.7 and about five hours before the main-shock, Mw 3.7 earthquake occurred in the Acıpayam basin. The earthquake, which was effective in 21 villages, severely damaged the villages of Ucarı, Kırca, Karahüyük and Apa. Buildings in the Acıpayam city center were not damaged. The earthquake caused 44 houses to collapse, 303 heavily and 225 lightly to damage. Totally 572 masonry houses without engineering service more than 50 years old built of adobe and rubble stone with mud mortar in the rural area collapsed and heavily to lightly damaged. In general, the northern and southern walls of the masonry houses in the villages located in the north-nortwest of the epicenter damaged and collapsed. A few mosques built of rubble with mud mortar were severely damaged and the minarets of a mosque was toppled. There was no damage to the buildings with engineering services and wooden carcasses. There were no casualties and injuries in the earthquake. The earthquake caused the death of a cow and injured a few cattle. Peak accelarations of 361.24g at K-G component, 184.42g at D-B component and 142.94g at the vertical component were measured at the Acıpayam strong-ground mtion station, which is 10 km away from the main shock. The maximum intensity of the earthquake was assigned as I 0 = VII (MSK). The earthquake was located in the region close to the intersection of NE-SW and NW-SE trending faults in the Acıpayam-Serinhisar graben of the left lateral strike-slip Fethiye-Burdur Fault System. The Acıpayam basin is a graben with approximately 5-15 km wide and 30 km long bounded by NW-SE trending normal faults in both margins. An N-S trending elongated ridge composed of Pliocene clayey limestones and bounded by approximately 15 km long fault on the western side is located in the middle part extending from Bedirköy, Yeniköy to Ucarı of the Acıpayam basin. The epicenter is is located at the intersection between NW-SE trending normal fault bounding the SW margin of the basin and subsegment lying between Ucarı and Yeniköy of the N-S trending fault. The focal plane solution of the main shock was determined N50W trending and dipping 42 0 to NE dip-slip normal fault with rake angle of-89 degrees. 100-150 m long and discontinuites, N10E striking en-echelon surface cracks ranging from 1.0 m to 10 m with right steps developped in 7 km east

A brief review of the geology of the tar sand areas of Nigeria is given. Analysis shows that the tar sand used for the tests consists of a well graded silty sand (cmf) with about 5% clay; and 3–5% bitumen. Results presented show a very high in situ compressive strength of about 450 kN/m2, a high ratio of tensile to compressive strength of about 22%, peak shear strength parameters of Cp′=15kN/m2and φp′ = 19° and residual parameters of Cr =0, φr = 18°. The compacted tar sand behaved like an overconsolidated soil with a preconsolidating pressure, Pc of 140 kN/m2. In general, the results of the in situ strength tests indicate that the Nigerian tar sand behaved as a soft sandstone.

Some instability problems of cutting slopes were found along the main road alignment between Bandung and Majalengka, which is mostly lying on high slaking claystones. The main objective of this paper is to establish the findings of the study devoted to some slope instability problems in the claystones due to their propensity to slaking at selected locations of these cutting slopes. The slope performance analysis made during a field survey has obtained a plot of slope angles versus slope heights for the average stable conditions of the existing road slopes, which were then combined with the laboratory experiments of slaking tests, resulting in a standard chart to be suggested as a physical-based model for the cutting slope design. Based on this chart, the optimum slope design can be estimated directly from the input of lithological characteristics determined by simple and inexpensive field and laboratory tests.

Aquifer ground water levels, gwl (bgl) levels were mapped for the Merti Aquifer boreholes traversing the Isiolo, Garissa and Wajir Counties, in order to aid the Predictions of the Groundwater levels in the study area. The algorithm was then used to predict the expected groundwater levels of a new area that hasn't been developed yet. The objective of the study is to help develop a groundwater management plan for the Merti Aquifer. The specific objective was to assess and evaluate groundwater availability at given depths of the vast study areal land mass. The groundwater levels are an essential parameter in that they are the difference between the water struck levels and the elevation in an area. Once predicted, it is easy to subtract it from the GPS-generated value of elevation above sea-levels, so that we get to know the water struck levels in a newly surveyed site. The water struck levels, or WSL, inferred from gwl,are actually the aquifer depths. This is then compared against the depth values generated via surface geophysics, before any drilling is undertaken, to minimize the probabilities of sinking a dry borehole. The parameters essential to this task will be longitudes, latitudes, elevation, aquifer depth, resistivity, and the groundwater levels, (gwl) in meters (below ground level) bgl. To perform the task of predictions, the Kohonen Self organizing Map (SOM) algorithm was used. The study concludes that the neural network SOM algorithm is an accurate predictor of the gwl in the Merti aquifer, since it clusters regions with similar groundwater levels together, and should thus be a useful tool in groundwater aquifer assessments, in the study area.

Foreword

A request was made to the Director General, Geological Survey of Bangladesh (GSB) by The Louis Berger Group, INC and Bangladesh Consulting Ltd. to provide a geological evaluation of Dhaka City for understanding of and planning of underground transportation system under Strategic Transportation Planning Project of the Government of Bangladesh. This evaluation report is prepared using geological investigation reports and technical papers available in the GSB. Emphasis is given to provide some concept on the sub-terrain environment and ground condition of Dhaka city. An interpretation on the engineering geological advantages and disadvantages for planning, designing and development of underground transportation system is done.

Summary

The City of Dhaka occupies a unique geological location in terms of the geological set up and ground condition. Geologically the city landmass is a part of an old terrace that is raised considerably up than the surrounding floodplains. The general elevation in the axial part of the city reaches up to about 6 to 7m above mean sea level (AMSL) whereas the surrounding floodplains are at about 4m AMSL.  The ground of the terrace is composed of Madhupur Clay (Pleistocene), consisting of very stiff to hard, reddish brown, highly ferruginous, plastic Clay-Silt with some minor contents of fine quartz-sand and iron concretions. The shear strength properties are considerably high and the average value of un-drained shear strength is ≈ 2 kg/cm2. The settlement characteristics indicate that the red clay to be an over-consolidated stratum. The geological history indicates that due long run erosion about 20m of materials have been removed from the top of the city ground. This indicates that an amount of ≈ 1 kg/cm2 of vertical stress has removed from the top of the existing ground surface. At present the average thickness of Madhupur Clay in the main urban area is about 7 meters.  The upper clay-silt stratum overlies a firm sand bed, geologically known as Dupitila Formation (Upper Tertiary). The geological and geotechnical properties of Dupitila  Sand (Upper Dupitila  Sandstone) tends to behave as soft rock. This soft sedimentary rock acts as  dense bedrock to hold most of the pile tips of all deep foundation which is uniformly distributed throughout the axial part of the city.

In terms of hydro-geological environment the Madhupur Clay Formation acts a wonderful cap over the Dhaka terrain. The top material is low in permeability and no ground water recharge occurs in the city area at ambient condition. The surface materials and natural topography with unique natural drainage system the flash-flood water has excellent run-off characteristics. The permanent and confined ground water level is located below 70m from the surface. The existing geo-hydrological environment provides better options for underground excavation. 

The existence of Madhupur Clay and Dupitila Sand below the urban feet turns the ground condition of Dhaka city to the best comparing the ground condition of many other cities of the world. Though Bangladesh is located at edge of most seismically active global zone, in terms of the ground condition the apparent seismic hazard* is relatively low in Dhaka city than most of other parts of the country (expected maximum Peak Ground Acceleration is 0.5g). A correlation on Shear Wave Velocity (Vs) of the geological materials underneath Dhaka city indicates that the value of Vs would be > 350 m/sec. Considering the geological and geotechnical aspects, the city of Dhaka has advantageous ground condition for construction of underground engineering structures including underground rapid transportation system.

(*Caution: The low seismic hazard does not mean lower seismic risk, as the risk is directly related to human activity and response to seismic issues.)

The aim of the article is to compare two classifications systems of engineering-geological environment sustainability in terms of its permeability evaluated on the basis of permeability coefficient. The first evaluated classification assumes a permeable environment to be a positive characteristic in the engineering-geological assessment, while the other considers an impermeable environment as favourable. The four fine-grained soil materials were selected, as they had very similar, almost identical grains-size distribution, but different microstructure characterized by grains sphericity, angularity, and roughness. At the same time, the influence of changes in the density of soil materials (density index 10%, 30%, 60%, 90%) was analysed. Permeability coefficient was determined using six methods (empirical formulae, laboratory and microscopic analysis). The laboratory method falling head test (FHT) was taken as a reference test that reflected the actual water flow through the soil. It was found that with an increase in grain angularity and roughness (and a decrease in sphericity), the permeability coefficient was decreasing and this trend culminated along with gradual compaction. Moreover, the research shows that unsuitable methods may classify soil materials into wrong engineering-geological permeability classes, which may have negative consequences during engineering-geological or geotechnical assessment and cause subsequent problems in foundation engineering.

The impact of Harold N. Fisk's work on the archaeology and geoarchaeology of the Lower Mississippi Valley (LMV) has been monumental. As a result of his landmark publications on the geology of the alluvial valley of the Mississippi River our comprehension of the interplay between geological, geomorphic, and human actions is relatively well developed. However, geologists and archaeologists still need to work together more closely to appreciate and understand the contributions each field has to offer. Examination of the interplay between geologists and archaeologists in the realm of dating and landscape evolution provides the basis for an investigation of the state of geoarchaeology in the LMV today. Integration of research demands an appreciation of scale which must be approached from an historical perspective. Humans have, both in the past and the present, impacted the natural environment of the Mississippi River and its floodplain. Only when this fact is fully appreciated by archaeologists and geologists alike will it be possible to forge a new synthesis of the relationship between the dynamic alluvial valley and its human occupants.

An engineering and environmental geological map of the Kathmandu Valley in Nepal has been elaborated within a project of German-Nepalese cooperation. In the Kathmandu Valley, the major geo-environmental problems arise from haphazard exploitation of geologic resources, local landslide zones, severe problems of garbage disposal, river flooding and a dramatic river pollution. The map was prepared by the use of GIS techniques. It contains all basic geological and environmental data, as geotechnical risk zones (landslide-prone areas or those of poor foundation conditions), areas for preferable extraction of construction material and those not to be allowed to be exploited, areas of immediate need of reforestation in order to prevent landslide or badland development, groundwater protection zones, and suitable garbage disposal sites.

This paper is a preliminary review of the large field embraced by climate and engineering aspects of the weathering of rock.Factors affecting weathering and the development of residual soils in general and their relationship to the engineering classifications of weathered materials are briefly discussed. The development of residual soils within four principal climatic zones of the world: periglacial, temperate, arid and humid tropical, is examined in more detail. The engineering behaviour of the residual soils in these zones is reviewed and compared, firstly by considering the engineering properties of the various soils and secondly by their performance as foundation material. The results of the review are summarised in the form of tables and figures.It is concluded from the work that generalized knowledge of climate and engineering behaviour of weathering rock and residual soils is helpful in the planning of engineering projects and in the economic design of site investigations, but it is emphasised each site must be investigated on its own merits.

An engineering and environmental geological map of the Kathmandu Valley in Nepal has been elaborated within a project of German-Nepalese cooperation. In the Kathmandu Valley, the major geo-environmental problems arise from haphazard exploitation of geologic resources, local landslide zones, severe problems of garbage disposal, river flooding and a dramatic river pollution. The map was prepared by the use of GIS techniques. It contains all basic geological and environmental data, as geotechnical risk zones (landslide-prone areas or those of poor foundation conditions), areas for preferable extraction of construction material and those not to be allowed to be exploited, areas of immediate need of reforestation in order to prevent landslide or badland development, groundwater protection zones, and suitable garbage disposal sites.

This paper introduces the current machine learning approach to solving spatial modeling problems in the domain of landslide susceptibility assessment. The latter is introduced as a classification problem, having multiple (geological, morphological, environmental etc.) attributes and one referent landslide inventory map from which to devise the classification rules. Three different machine learning algorithms were compared: Support Vector Machines, Decision Trees and Logistic Regression. A specific area of the Fruška Gora Mountain (Serbia) was selected to perform the entire modeling procedure, from attribute and referent data preparation/processing, through the classifiers' implementation to the evaluation, carried out in terms of the model's performance and agreement with the referent data. The experiments showed that Support Vector Machines outperformed the other proposed methods, and hence this algorithm was selected as the model of choice to be compared with a common knowledge-driven method – the Analytical Hierarchy Process – to create a landslide susceptibility map of the relevant area. The SVM classifier outperformed the AHP approach in all evaluation metrics (κ index, area under ROC curve and false positive rate in stable ground class).► After conducting experiments based on the sampling over the entire area, the SVM turned to be the model of choice. ► In the mapping task on a neighboring terrain, SVM achieved better performance than AHP model in all evaluation measures. ► The results of the 2nd mapping task were weaker in comparison to the 1st one (different distribution of input parameters). ► SVM do not need any feature selection technique as opposed to some other methods such as Decision Trees.