Engineering Geology and Geotechnical Problems Research Papers (original) (raw)

A new approach is developed to determine the shear wave velocity in saturated soft to firm clays using measurements of the liquid limit, plastic limit, and natural water content with depth. The shear wave velocity is assessed using the site-specific variation of the natural water content with the effective mean stress. Subsequently, an iterative process is envisaged to obtain the clay stiffness and strength parameters. The at-rest earth pressure coefficient, as well as bearing capacity factor and rigidity index related to the cone penetration test, is also acquired from the analyses. Comparisons are presented between the measured clay parameters and the results of corresponding analyses in five different case studies. It is demonstrated that the presented approach can provide acceptable estimates of saturated clay stiffness and strength parameters. One of the main privileges of the presented methodology is the site-specific procedure developed based on the relationships between clay strength and stiffness parameters, rather than direct correlations. Despite of iterative processes, the presented approach can be easily implemented using a simple spreadsheet, benefiting both geotechnical researchers and practitioners.

Interaction between pile and soil is one the most important cases in Geotechnical engineering and also related sciences. Many of scholars have already explored this issue and examined various aspects of the behavior of piles under influence of different loads. Due to increasing of Micro piles in the last decade and Liquefaction dangerous due to earthquake, in this study micro pile bearing capacity is considered. Numerically, Micro piles behavior for reinforcing of saturated soil is studied. 3-D dynamic finite element method for analyzing of saturated porous condition based on the Biot equations has been used. Governing equations consist of soil displacement and water relative displacement as initial variable are supposed. Cyclic Elasto-plastic behavior of soil under earthquake loading is simulated by using a generalized plasticity theory composing of a yield surface together with non-associated flow rule. In this study, effects of model with one micro pile, without micro pile and model with micro piles group are investigated on the liquefaction potential.

This paper examines biocementation via the microbial-induced carbonate precipitation (MICP) process as an appropriate and promising new technology for stabilisation of loose sand and silty sand deposits as a method to mitigate wind erosion. The technique involves spray treating the sand surface layer with a mixture of cementation and bacterial-cell solutions, the ensuing reactions causing calcite precipitation to occur between the sand grains, thereby lightly cementing them together over time. The bench-scale experimental programme presented investigates the proposed technique's effectiveness for stabilisation of silica and carbonate sands with different gradations, determination of the optimal reagent concentrations, the time-dependent shear strength development for the crustal sand layer following single-and double-MICP spray treatments, as well as wind tunnel experiments. Of particular novelty were investigations of the effect of dew formation on crustal shear strength development with curing period and the efficiency of the MICP treatment for the outdoor environment compared to laboratory-controlled test conditions. The wind tunnel experiments demonstrated that 28-day cured singly MICP-spray-treated crustal sand layers were stable to simulated 20 m·s−1 winds measured at 20 cm above the layer surface.

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.

- by Meshack O Amimo
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- Geomorphology, Artificial Intelligence, Machine Learning, Hydrology

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.

Rainfall is one of the vital form of precipitation which affects not only agricultural activity but also entire ecology in any region. Hence rainfall distribution and its trends in district is important to understand water availability and to take decisions for the agricultural activities in area. This research paper is an effort to assess the spatial and temporal rainfall variability of Ahmednagar district of Maharashtra State. Ahmednagar is popularly known as the largest district of Maharashtra with fourteen Talukas. The average annual rainfall of this district is 621 mm with an average of 46 rainy days. In this study the spatial and temporal rainfall distribution of this district is taken in to account. Short-term annual rainfall data are considered from 1998 to 2014. The daily rainfalls of monsoon months of all the fourteen Taluka are analyzed for the year 2015.It was found that spatial and temporal variability is high in the District.

For Madagascar, road construction is a primary field. The road has various functions, not only it played a major role in linking region, but it also influenced the economic and social development of an area. This study is specifically concerned with Secondary National Road n°5 construction that involve Soanierana Ivongo and Maroantsetra in choosing selected materials. Thus, it is considered important to study Antanifotsy silt loam deposit; to look into its technical character, economicand environmentalpotentiality as an appropriatedeposit for road construction. Data for this project were gathered through bibliographicresearch, interview, survey,questionnaireand field observations;including data treatmentsandscrutinyassigning into softwareprograms.As a result, according to geotechnical analyses and characterizations, it reveals that this material has great potential for geotechnical properties. For that reason, it can be used as road structure. In addition, the rock geometry existing in the area was highlighted by the deposit petrography, pedology criteria and its geologic model. Silt loam deposits in the area was estimated 208 261.6 m3and 189 271.2 m3for the clay. On the basis of the distance between Antanifotsy and Manompana road construction, it can be concluded that the deposit reserve is largely sufficient. Hence, it shows that open pit mining in simultaneous horizontal tranchesis the best way to exploit that is likely done after two months and a half.Furthermore, some environmental measures wereconductedin order to minimize the area morphology destruction and natural resources. Consequently, reforestation that contributes to the revegetation of the exploited territory is essential.Key words:Antanifotsy, silt loam, optimization, road technology, geological model, miningexploitation.

In this paper site, investigation was carried out to reveal the site subsurface condition, determine bearing strength, predict settlement and recommend foundation for a 20,000us gallons elevated Braithwaite water tank. Method involved the boring of 3geotechnical boreholes to a depth of 10m, sampling and laboratory analysis.Results indicatethat very soft, organic sensitive to extra-sensitive, highly collapsible, high compressibility overconsolidated clays underlie to a depth of 8m. The moisture content of these clays varies from 120.15 – 128.0%, wet unit weight from 13.99 – 18.63KN/m 3 , and specific gravity of 2.35 2.56. Liquid limit ranges from 66.9 – 67.1%, plastic limit from 29 – 31%, plasticity index from 36.1 – 37.9% on the basis of which they classify as ilmenites. Their linear shrinkage ranges from 10 – 13.1%, collapse potential from 0.161 – 0.234 with allowable bearing capacity of 113.22KN/m 2 and total settlement of 166.14cm, raft foundation with pre-treatment of foundation...

This paper represents a new advance in the study of engineering properties and material applications of phyllite clays. Considering their potential use as construction materials for structures subjected to low stress levels, this laboratory research investigated the stabilization and improvement in engineering properties of a Spanish phyllite clay achieved by the addition of 3, 5 and 7 wt.% lime. Geotechnical properties investigated include the consistency limits, compaction, California Bearing Ratio, swelling potential and water-permeability. The phyllite clay–lime mixtures had good compaction properties and very to extremely low permeability-coefficient values, with a semi-logarithmic correlation between increasing permeability and increasing proportion of lime additive. The addition of 3 wt.% lime was sufficient to reach the index of capacity amble specified in the Sheet of Technical General Prescriptions for Works of Roads and Bridges PG–3 (Spanish Highways Agency, 2008), significantly reducing the plasticity index value, with the compacted mixture undergoing no swelling under soakage. The required pavement thicknesses for the raw phyllite–clay material and the phyllite clay–lime mixtures are compared and discussed. Potential applications for phyllite clay–lime mixtures include for pavements/road sub-grade, earth construction, building materials and for impermeabilization purposes.

- by Brendan C . O'Kelly
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- Geotechnical Engineering, Soil Mechanics, Clay Minerals, Pavement Materials

This briefing highlights the difficulties of standard triaxial compression testing of fibrous peat and representing its
behaviour in a Mohr–Coulomb framework. Experimental values of effective angle of shearing resistance, phi', and apparent cohesion, c', reported in the literature for fibrous peat are scrutinised, from which the authors conclude that high phi' values determined from triaxial compression testing can be grossly unconservative. Furthermore, given that shearing in a peat which is not completely humified involves tearing of entangled fibres and cellular connections in addition to shearing at frictional contacts, the authors postulate that the apparent cohesion value of fibrous peat is most likely greater than zero. Hence fundamental research on peat strength and how it is derived needs to be performed; also there needs to be further development of existing and new specific material models to simulate more accurately the soft and viscous nature of peat, and the general cross-anisotropic fabric and reinforcement
provided by fibres in peats with low humification.

O’Kelly, B. C. (2022) Discussion of “Advancement in estimation of undrained shear strength through fall cone tests” by Abhishek Ghosh Dastider, Santiram Chatterjee, and Prasenjit Basu. Journal of Geotechnical and Geoenvironmental... more

ABSTRACT: Ground improvement using PVD was applied successfully for increasing foundation stability and controlling residual settlements of the container yard constructed on 35 m thick soft clay deposit at CMIT, Vietnam. The treated area is about 40 ha including vacuum consolidation combined with 6.3 m embankment surcharge for a strip of 57 m along the river bank (VCA) and conventional surcharge preloading using 9.1 m sand fill embankment for the remaining area. The monitored data indicated that PVD thickness of 3 mm arranged in spacing of 0.9 m to 1.2 m can be used successfully for improvement of thick soft clay deposit in both methods of embankment preloading with and without vacuum pumping. Performance of reduced embankment combined with vacuum pumping is very much better than that of conventional embankment preloading in terms of shortening construction time, reducing lateral displacement, increasing stability, and minimizing residual settlement. Back calculated ch value is dependent on the assumptions of smear effects including smear zone ratio, ds/dm and permeability ratio, Rs = kh/ks. For ds/dm = 2 as commonly used, the back-calculated ch value is directly proportional to Rs and the value of Rs in vacuum consolidation seems significantly smaller than that in embankment preloading. Using the back-calculated results of compressibility and flow parameters, the time-settlements re-calculated by 1-D method are in very good comparison with measured data for both conventional preloading and vacuum consolidation considering the vacuum pressure as an induced vertical stress distributed uniformly in the PVD zone. Analyses of factor of safety from observed pore pressures during embankment construction illustrated that the commonly used stability chart as given by Wakita & Matsuo (1994) is too conservative for PVD improved soft ground. Secondary compression behavior of thick soft ground improved by PVD including back calculation for coefficient of secondary compression and estimation of long term residual settlement have also been provided.

- by Arumugam Balasubramaniam and +1
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- Civil Engineering, Geotechnical Engineering, Engineering Geology and Geotechnical Problems

Hemophobia fear of blood, is a type of specific phobia. The present study was aimed to know the Hemophobia among 8th to 10th studying students in rural and urban Government schools. The response was taken from 3399 students (8th:1175, 9th:1095, 10th:1129). The study found that the phobia was more in Namburu school students (21.31%). In the urban schools the highest percentage was noticed in SJRR school (28.96). Homeopathy, Exposure based therapy, Cognitive therapy are some of the useful treatment methods. Parents shall not neglect any specific phobia, which can influence the future.

- by Dr. Costas Sachpazis
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- Civil Engineering, Road safety, Rock Mechanics, Geotechnical Engineering

Peatlands are dynamic eco-hydrological wetland systems, increasingly under threat worldwide due to natural and anthropogenic effects, including large-scale drainage and oxidation, causing their subsidence and ecological deterioration. In Europe, the requirements for conservation, restoration and long-term sustainability of degraded active bog have been accentuated by more stringent environmental policy and legislation. This paper describes how peat bunds (dams), strategically constructed at affected areas around the bog margins, can gradually re-establish the natural peatland hydrology and peat-forming vegetation through collection, storage and controlled release of surface runoff from the high bog. For geotechnical stability, the translational-type slip failure was identified as the critical case. The analysis must account for drying out of the compacted peat during drought periods and ensuing increases in lateral and uplift hydraulic pressures and seepage pressures generated follo...

The choice and dimensioning of the foundations are made according to the physical properties of the soil and the type of structure to be built. This research concerns the assessment of the KAMATANDA platform soil capacity, which has to support series of crushers and mechanical launders. Laboratory tests determined the physical properties (moist unit weight, dry unit weight, moisture content and particle size analysis) from soil samples taken at four different depths. In situ, we determined the mechanical properties of the soil by the dynamic cone penetrometer test. The soil of the KAMATANDA platform was the poorly graded sands by size classification. By doing the test, the moisture content, the moist unit weight and dry unit weight were increasing from 0 to 5 meters. The compactness was increasing when going deep but the rate of increase was getting less from 2.5 meters' depth. The soil presented the heterogeneities and the depth presenting much resistance to the penetration of the dynamic cone penetrometer was 2.4 meters. To avoid differential settlements, the embedding height was 1.2 meter. As per the minimum values, the dynamic resistance evaluated through the Dutch formula was 2.1MPa; however, the allowable bearing capacity, based on the dynamic resistance as per L'HERMINIER formula was 0.105MPa. We therefore noticed that, the resistance of KAMATANDA ground after dynamic cone penetrometer test relates to the compactness of the soil that grows according the depths.

Ground vibrations due to blasting processes are one of the fundamental problems in the mining and civil excavation industry which may cause severe damage to the structures. It is mostly recommended that a detail comprehensive vibration control is required. This paper presents the results of ground induced vibration at a metro rail station excavation site in the heart-of-city of Bangalore. This study was carried out to control ground induced vibration, fly rock near to sensitive structures, mostly to the city civil court and the buildings of Sir M Visveswaraya college and like statue, school, public and private structures closed to 10-15m. More than 60 blasts were done under control supervision of government officials. The maximum charge/delay, charge per hole, delay in between holes and rows were established on basis geological rock mass. Ninety percent rock was excavated to construct underground metro stations. The fly rock was control by optimum stemming lengths and by using suitable fly control rubber mat.

Given the security problem in Nigeria particularly in the North, the need for geospatial analysis of security in Bauchi metropolis in relation to police stations cannot be overemphasized. Apart from the prevalence of security problem in the area current analyses are inadequate, almost non-existent. To tackle this problem, Global Positioning System (GPS) was used to take the coordinates of the police stations in the study area, while the attribute data relating to the number of police personnel in each station were collected using interview and documented data. The data were analysed using simple ratio. Also ArcGIS (Version 10.0) software was used to show the map of the distribution. A nearest neighbourhood analysis has shown that the distribution of stations is random in the area. One and two kilometre buffer zones were generated and the result shows that the old city of Bauchi and the eastern part of the metropolis were fully served while the western and southern parts were underserved. The ratio of population in the area to a police is 898:1 which is far below the United Nation recommended figure of 450:1. The work recommends that there is need for population consideration in citing police stations in the area as well as increasing the work force as means for achieving a holistic security for the metropolis.

- by Ikharo Braimoh and +1
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- Geology, Structural Geology, Petroleum geology, Engineering Geology and Geotechnical Problems

Engineering failures are hard to define. They may form catastrophic disasters that are serious threats to public safety; yet, at other instances, they may be a shortcoming in the behavior or function of structures. A functional shortcoming, unforeseen and unplanned for, of an engineered element, may sometimes be considered a failure while at other times seen as tolerable or even advantageous. Engineers always regard failures as their greatest enemy; ironically, failures may be considered as their foremost teacher as well. Without failures, much of the current advances in design would not have been gained. Studying well-documented failures is important as the findings can be used to improve the designs and performance of structures. In this article, the different aspects related to failures and their prevention are explored. A conceptual model for the cost of failures is also presented. Additionally, some of the well-documented case histories of failures encompassing a wide range of geotechnical practices are highlighted and the learnt lessons are emphasized. It is demonstrated that failures may be substantially reduced by carrying out proper geotechnical site investigations, adopting flexible designs that incorporate observations during construction, applying strict site supervision, implementing geotechnical instrumentation programs and embracing risk management principles.

The three major characteristics of rainfall are mainly its amount, frequency and intensity. The value of rainfall varies greatly from day to day, place to place, month and year to year. Generally Akole tehsil receives the highest rainfall and Karjat and Jamkhed tehsils receives the least rainfall. The main reason for the highest rainfall in Akole tehsil is orographic type rainfall. The rainfall characteristics and distribution in drought prone area in study area. The research covers rainfall data from 1981 to 2014 and the rainfall data is taken from the statistical department website of Ahmednagar district.

Using high-quality hydraulic conductivity test results for compacted soil samples with widely different gradation characteristics, 14 commonly employed empirical correlations for estimating the permeability coefficient (k) were evaluated. Comparisons of measured and predicted k values indicated most predictions were within a margin of ±100%, although they could vary by up to 500% or more. Statistical analysis indicated that high coefficients of determination obtained for these datasets can be grossly misleading, since the data may have markedly high values of the standard error of the estimate. Grain size characteristics and void ratio were identified as the most sensitive input parameters for the models investigated. On this basis and using the results of hydraulic conductivity testing performed on 20 soil samples with very different gradations, a new prediction model that expressly considers both gradation and void ratio is proposed. Test results from an additional 16 sandy soil samples were used to validate the new model, which was found to produce a fairly good distribution of data points within 95% prediction intervals and an equitable spread about the unity line in a plot of predicted against measured k values. The experimental data were also analysed using the grading entropy framework.

- by Brendan C . O'Kelly
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- Soil Science, Geotechnical Engineering, Soil Mechanics, Soil ecology
- by Pranav Muktibodh
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- Rock Mechanics, Geotechnical Engineering, Soil Mechanics, Engineering Geology

The consolidation test is one of the most common laboratory tests in geotechnical investigations. It is mainly utilized to assess the clay operative constrained modulus, which is an essential parameter in the settlement calculations of foundations and embankments. Recently, the non-linear numerical modelling has become more common than ever in geotechnical engineering. The state-of-art advanced geotechnical analyses focus on consideration of the nonlinear variation of soil moduli with the stress and strain levels. One of the fundamental quantities in advanced non-linear geotechnical analyses is the small strain shear modulus. It is obtained by measuring the shear wave velocity using special tests or amendments to traditional tests. Such tests and/or amendments are generally much less common and more expensive than consolidation tests. In this paper, the shear wave velocity and small strain shear modulus of soft to firm clays are evaluated from results of consolidation tests. The site-specific constants that relate the void ratio to the shear wave velocities and small strain shear moduli are concluded from the water content measurements. The proposed approach is validated by analysing two well-reported clays (viz., Ariake and Singapore clays). The results of the analyses show the viability of the proposed approach as the estimated moduli are close to the values inferred from the field shear wave velocity measurements.

Abstract
The renovation of a proposed railway bridge in Akere, North Central Nigeria was investigated using integrated Geotechnical (SPT) and Geophysical methods (2-D and 3-D resistivity imaging using multi-electrode system and extracted vertical electrical sounding techniques). Frequent flooding from the Niger River on overflowing it’s banks have been washing away the railway section along this section and several engineering foundation precaution taken have proved abortive. Eight traverses of 2-D lines, one 3-D section and sixty four extracted VES data were acquired and interpreted. Inter electrode spacing of 1m and inter traverse spacing of 3m were adopted for better near surface resolution. The subsurface layers were characterized by top soil, clay, clayey sand/sandy clay, weathered/intensely fractured rock, sand and fresh basement. The 8 borehole data earlier acquired were integrated with the 2-D and 3-D Resistivity tomography results. A perfect correlation was obtained for the two techniques. However all the boreholes terminated at shallow depth (5 – 11m), and did not provide information beyond this depth while the Resistivity tomography penetrated to a depth of about 15 – 20m and revealed the presence of structurally weak materials (Clay/Fractured basement) inimical to the foundation of the rail line along the traverses. The 2-D and 3-D resistivity tomography shows that the first aquifer is underlain by clay layer separating the upper aquifer unit from the lower aquifer unit, this was further corroborated by the VES results. The presence of low resistivity subsurface materials compose of clay/clayey sand within a depth range of 10 –17m may accelerate failure of piles along the Railway line. This layer is inimical to the proposed rail line. The depth to the competent soil material along where the failed (10 to 20m) piles were installed varies compared to adjacent regions (3 – 6m). It was therefore recommended that necessary precaution in foundation design to competent layer or to exploit the adjacent shallow competent region be considered. Pile foundation to varying depths within the competent region is recommended and should be socketed and anchored within the basement rock which occur at varying depths within the investigated area. The integration of geotechnics and invaluable multi-dimensional variation of subsurface distribution provided in the geophysical investigation have provided an insightful and lasting solution to the foundation problems encountered.

- by waliu Adeolu and +1
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- Engineering Geology, Near surface Geophysics, Engineering Geology and Geotechnical Problems

This paper presents a review of literature related to the vacuum consolidation ground improvement technique, focusing on issues affecting efficiency of performance and the application of the technique in peaty ground. Although it is now widely considered to be effective for reducing post-construction settlement, studies on vacuum consolidation in peat have, to date, mostly been limited to field trials. This paper offers an overview of the development and theory behind the technique. Issues affecting the efficiency of vacuum systems and recent advances in predicting the ground response to vacuum preloading are described. The application of the technique in peaty soils is investigated; an overview is also provided of some geotechnical properties that distinguish peat from soft mineral soils, highlighting lessons learned from relevant case studies.

Composite materials have been used for over 20 years as temporary reinforcement in concrete structures, since the first GFRP soft-eye in Bangkok metro (1996). However, FRP rebars are only exposed to loads limited to 20% of their ultimate strength, as per ACI440 design guidelines. The concern behind this limitation is creep – also identified as ‘static fatigue’ – that occurs in all material, metallic or composite. Creep-Rupture behavior of FRP material as predictive models are available to design post-tensioned anchors in carbon-FRP (CFRP) and even glass-FRP (GFRP) according to their expected service-life. In the case of Doha metro, both systems have been used based on a conservative expected service-life of 10 years.

Hydraulic in situ measurement of rock mass permeability by packer (Lugeon) testing is an inherent and integral element of many engineering, hydrogeological and mining investigation. This paper describes and discusses geotechnical testing in the design process from a consulting practitioner’s perspective. This study focuses on the Packer testing planning, procedure, results & interpretation. Packer test system is an optimum method for obtaining values of hydraulic conductivity in wells that are difficult to analyse using conventional slug test systems. Packer tests are carried out to assess the variability of a borehole as it intersects various hydrogeological units. It gives vertical distribution of hydraulic properties and water quality in the aquifer and usually cheaper than a nest of wells and gives more continuous record and this knowledge can often be essential for a proper design. The role, objectives, types and interpretation of testing, limitations and recommended good practices as part of the geotechnical design process are outlined through the examination of test data from a case record.

Analysis and interaction of soil considering different pile foundation types and their comparative relationship is a study breach that leads to future uncertainty, thus research is essential to properly carry out the performance of those piles constructed nowadays. This implies the type of piles such as under-reamed and friction pile. When structures are erected on a soil stratum because of the applied load the interaction on load carrying capacity of pile and soil is important to understand whether the ground below the structure can take the load safely without causing any structural damage. In this research the interaction of pile and soil for specific site in Addis Ababa city located in front of stadium project of Wogagen bank share company was selected to compare load carrying capacity of under-reamed and friction pile. Finite element simulation provides as a valuable resource as it saves time and money; thus, it can be used at least for preliminary design of foundation to understand load carrying capacity and settlement of foundation. For carrying out elastoplastic analysis in this research geotechnical software called Plaxis 3D foundation is used and this software applies finite element analysis method for simulation of the models. From the simulation displacement of the under-reamed and friction pile is used as a comparing parameter. The displacement of under-reamed and friction pile decreases as the diameter of the piles increases, which shows decreasing displacement behaviour of the piles is good for foundation. Comparing the simulated displacement output of the under-reamed pile of 600mm, 900mm and 1200mm diameter it shows greater displacement by 83%, 75% and 67% respectively than of the frictional piles of diameter 600mm, 900mm and 1200mm.

Geologically, the Dhaka-Tongi area consists of parts of high inlier, along narrow tract of older sediments hosting the major parts of the city and surrounded by very young riverine sediments occupying the surrounding valleys. The drainage patterns of this tract consist of two types, dendritic and trellis. The older sediment sequence consists of sandstone of Dupi Tila Formation overlain by by the Madhupur Clay. The Clay is overlain by alluvium, but is locally exposed in stream valleys. The region can be divided into three types of landforms – a central high area, a complex of high and lowareas band a complex of low areas. The ground condition with respect to construction can be rated as: favourable, poor and hazardous. The techniques for ground improvement depend on the ground conditions which are intimately related to the geology (sediment type and structure) and geomorphology (landform and elevation). The type of site preparation techniques applicable during pre-construction development are variable from simple removal of the surficial soft soil followed by a sand fill and compaction to more complex techniques of using geotextile, grouting, preloading and surcharge. Taking account of above, a model is suggested which can be used to choose the appropriate ground improvement technique.

Soil classification systems represent powerful tools not only to facilitate soil identification, but also to predict its possible behavior. While the use of arbitrary standards based on particle size distribution may be applicable to coarse-grained soils, those approaches based exclusively on textural principles are ineffective in classifying fine-grained soils, where clay content and its mineralogy dictate the general properties. In this sense, the measurement of plasticity represents a more appropriate parameter than particle size. This fact has led various authors and technical committees to develop fine-grained soil classification systems based on plasticity. However, the disparity of criteria makes it necessary to review them in order to glimpse the weaknesses and strengths of each of them. This paper includes the review of the six main existing proposals together with the possible variants arising from them: Casagrande (1947)-Unified Soil Classification System (USCS), American Association of State Highway and Transportation Officials (AASHTO), Federal Aviation Agency (FAA), Saito and Miki (1975), Polidori (2003, 2007, 2009) and Moreno-Maroto and Alonso-Azcarate (2017, 2018) classification charts, which are designed on the basis of Atterberg limits. After conducting a complete and thorough examination, it is shown that although the Casagrande (1947)-USCS approach is the most widely known, of all the proposals examined, only that of Moreno-Maroto and Alonso-Azcarate (2017, 2018) is based on well-founded criteria, presenting a strong predictive capacity, as well as being simple, precise and adaptable to needs.

Basically about Geology and Geotechnical parameter of Sarangkot area

Site investigation is essential prior to all construction activities of engineering structures for determining the suitability of the site for the construction of the proposed structure. The results from the site investigation gives us the information about the soil profile and the ground water table condition at the site. Various in-situ tests are carried out like Standard Penetration Test (SPT), Electrical Resistivity Technique (ERT), Vane Shear Test (VST), Plate Load Test (PLT), Pile Load Test, Flat Plate Dilatometer Test, Packer Test, Cone Penetration Test (CPT) and many others during the site exploration. The data and results obtained from these tests are essential in identifying the soil type, analyzing and the strength and deformation properties and parameters of soil as well as the ground water condition of the site. This paper intends to summarize the processes and various corrections that are involved in Standard Penetration Test (SPT) and its importance and implication in geotechnical analysis and site exploration. The tools and equipment in this test involved are cable percussion drilling rig, soil sampler (especially split spoon sampler), spirit level, boring machine and a hammer with few other miscellaneous. The soil sampler is pushed or penetrated into the ground by hammer of 63.5kg making it fall freely from a standard height of 750mm. The collected disturbed and undisturbed soil samples, hammer blows and energy are analyzed and interpreted to determine or more specifically to estimate the shear strength of soil, relative density and bearing strength of the soil at different depths. This test also helps in determining the aspects of soil which later can be improved by soil stabilizing or by any one or combination of various ground improvement techniques. In accordance of these interpretations, analysis and estimates, suitable foundation design and further construction work for the proposed structure are recommended.

Using piles in the foundation had escalated as the number of high-rise buildings had increased through the past years. The main purpose of piles is to transmit loads from shallow weak layers to deeper and stronger layers of soil. That type of foundations is used to fulfil both bearing capacity and settlement control requirements. The pile group bearing ultimate load and pile group settlement are affected by many factors such as the pattern of piles, the piles diameter, the piles length, the spacing between piles and the surrounding soil type and state. The behaviour of the group of piles is completely different from that of a single pile. In this paper, The behaviour of the groups of piles under vertical loads in overconsolidated clayey soil is studied using advanced numerical modeling and compared with the behaviour of the single pile at a well-documented case history. KEYWORDS Group of piles, pile group action, pile group efficiency, settlement of group of piles, overconsolidated clay.

Sıvılaşma, Sıvılaşma Nedir? Sıvılaşma Analizi, Zemin Sıvılaşması Nedir? Zeminlerin Sıvılaşabilirliği, Zemin Sıvılaşması İle İlgili Genel Tanımlar, Zemin Sıvılaşması İçin Mühendislik Analizleri ve Değerlendirmeler, Zemin Sıvılaşmasının Analiz Aşamaları, Zemin Sıvılaşması İçin Gerekli Koşullar Nelerdir? Zemin ve Temel Etüdü Uygulama Esaslarında ve Rapor Formatında Sıvılaşma Konusunun Geçtiği Bölümler, Hangi Tür Zeminler Sıvılaşmaya Daha Yatkındır? Zemin Sıvılaşmasının Mühendislik Değerlendirmesi, Ön Sıvılaşma, Gerçek Sıvılaşma, Sınırlı Ön Sıvılaşma-Çevrimsel Hareketlilik, Kum Kayması, Mikroskobik ve Makroskobik Sıvılaşma, Zemin Sıvılaşmasının Çeşitleri Nelerdir? Zemin Sıvılaşması Nasıl Oluşur? Zemin Sıvılaşmasına Etki Eden Faktörler Nelerdir? Zemin Özelliklerinin Sıvılaşmaya Etkisi, Zemin Sıvılaşmasına Hangi Tür Zeminlerde Rastlanılır? Zemin Sıvılaşması İçin Temel Analizler, Zemin Sıvılaşması İçin Arazi Araştırmaları ve Deneyleri, Zemin Sıvılaşmasının Etkileri ve Sonuçları Nelerdir? Zemin Sıvılaşması Nasıl Gözlenir?Zemin Sıvılaşması-Deprem İlişkisi Nasıl Açıklanabilir? Zemin Sıvılaşması İle İlgili Genel Bilgiler, Zemin Sıvılaşması İle İlgili Alınması Gereken Tedbirler, Önlemler ve Tavsiyeler, Zemin ve Temel Etüdü Uygulama Esaslarında ve Rapor Formatında Sıvılaşma İle İlgili Bilgiler, Ankara, Jeoloji, Jeoloji Mühendisliği, Jeoloji Yüksek Mühendisi, Türkay Ercan Şengöz. (Türkay Ercan Şengöz tarafından yayımlanan her çeşit harita, bilgi ve belgelerin her hakkı saklıdır. Her ne şekilde ve amaçla olursa olsun bu bilgi ve belgelerin kaynak belirtilmeden kullanılması, yazılı izin alınmadan elektronik, optik, mekanik veya diğer yollarla dağıtılması, çoğaltılması, basılması, değiştirilmesi, paylaşılması, kopyalanması ve internet sitelerinde kullanılması durumunda gerekli hukuki yollara başvurulacak ve yasal işlem başlatılacaktır. Önemle duyurulur. Bu platformda veya diğer platformlarda paylaşmış olduğum tez veya akademik kapsamdaki çalışmalarımın içerisindeki bütün bilgilerin etik davranış ve akademik kurallar çerçevesinde elde edilerek sunulduğunu, akademik çalışmalarımın tez yazım kurallarına uygun olarak hazırlandığını hatırlatıyor, bana ait olan her türlü ifade ve bilginin kaynağına eksiksiz atıf yapılması gerektiğini bildiriyor, sevgi ve saygılarımı sunuyorum.)

- by Türkay Ercan Şengöz
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- Engineering, Civil Engineering, Geology, Geophysics

Недостаточный уровень инженерно-геологических изысканий сегодня – результат общего принижения их значимости, недостаточного финансирования, формальной и мелочной регламентации их проведения. Достаточно быстрое развитие методов обработки, математического моделирования и лабораторного оборудования сопровождается тем не менее быстрым ростом доли фальсифицированных отчетов по результатам проведения инженерно-геологических изысканий, которая уже достигла совершенно критической величины. Современная практика экспертизы изысканий фактически не препятствует появлению подобных материалов. Формальный ее характер в большей мере затрудняет утверждение и согласование как раз достоверных материалов. Предложено использовать воздушные инспекции с помощью беспилотных летательных аппаратов и выполнение контрольного бурения, зондирования и т.д. Указан возможный механизм финансирования подобного контроля.

Phobias are common in human life. Exam phobia is the most common phobia among the school students. The present study was carried out to know the level of the exam phobia among 8th to 10th Government high school students in. The response was taken from 2981 students (Male: 1589. Female: 1392). The study found that out of the total male students, 38.45% students expressed the phobia. In the case of female it is 45.26. Researchers reported that phobia of examination affects the academic performance of the students in the examination and they could not perform according to their knowledge due to a phobia of examination as they forget the answers to some questions during examination due to nervousness and a phobia of examination. Homeopathy, Exposure based therapy, Cognitive therapy and Relaxation techniques are some of the useful treatment methods. The authors suggested to follow the exam preparation tips to reduce exam phobia.

This report helps student of engineering geology and engineering geologist in the construction field as hand guide for the study of rock mass and intact rock and also for their classification. This report prefers two classification system for rock mass that are Geomechanics classification (Bieniswski 1989) and Q- System classification (Barton et al. 1974).

- by Navin Thapa
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- Engineering Geology and Geotechnical Problems

ABSTRACT
Geotechnical site investigation is the process of collecting data and evaluating the conditions of the site for the purposes of obtaining earthworks design and earth-fill material which is suitable for foundation stabilization. The main purpose of a site investigation is to determine sufficient site information that is used to select a site with suitable earth-fill material for foundation stabilization.
The objectives of this site investigation were to determine texture, consistency, shear strength, bearing capacity and settlement properties of the material. The methodology used includes material sampling, sieve analysis, Atterberg limit tests, compaction test and California Bearing Ratio test.
Laboratory test results indicates that gravel particles dominate the material within the Tswinga area with an average percentage of about 74%. The site investigation also indicates that the Tswinga borrow pit material has an average liquid limit of about 30% with the plasticity index of about 11%, therefore the material tends to have medium plasticity index due to the abundance of clay shows expansion ability. The material is classified as clay, sandy and gravel (A-2-6) as according to the AASHTO classification system. The material samples maximum dry density at modified AASHTO compaction effort was within the range of 2122 kg/m3 to 2147 kg/m3 at optimum moisture content of 6.9% and 9.3% respectively. Material with this compaction effort has the settlement properties and bearing capacity suitable for foundation stabilization due to their great strength, therefore are classified as gravel. The CBR values at compaction efforts between 90% and 100% of the modified AASHTO varied from 11 to 49. The results showed that the have CBR values ≥ 25 at 95% modified AASHTO. This confirm that the material is of high bearing capacity.
This investigation of the earth-fill material from indicates that the material within Tswinga area are excellent too good which is suitable for foundation stabilization. It is strongly recommended that the earth-fill material from Tswinga area can be used to replace unsuitable soil for foundations stabilization.