scholarly journals Development of a Unified Geotechnical Database and Data Processing on the Example of Nur-Sultan City

2020 ◽  
Vol 11 (1) ◽  
pp. 306
Author(s):  
Askar Zhussupbekov ◽  
Nurgul Alibekova ◽  
Sungat Akhazhanov ◽  
Assel Sarsembayeva
Keyword(s):  
Elasticity Modulus ◽  
Soil Layer ◽  
Engineering Properties ◽  
Driven Piles ◽  
Geological Surveys ◽  
Geotechnical Database ◽  
Geological Origin ◽  
The City ◽  
Pile Length ◽  
Physical And Mechanical Characteristics

Development of a geotechnical database for the young capital of Kazakhstan, Nur-Sultan city, became a paramount concern of both the scientific community and industry. The creation of the Kazakhstan model of the geotechnical database was based on a fixed dataset which included a city map with determined X, Y, and H coordinates and the user generated data obtained from the materials of engineering and geological surveys from more than 2000 boreholes. Based on the assessment of the built-up area of the city, six main engineering-geological elements (EGE) were identified. The territory of the city was regrouped into eight zones instead of the previous six based on the geological origin and stratigraphy interposition of the EGE. Engineering properties of the soils were considered for physical and mechanical characteristics, where the plasticity limits demonstrated an accurate correlation to the elasticity modulus E and distribution boundaries between the alluvial and eluvial types of the soil on the graph. So, the increased liquid and plastic limits are replicated by higher values of elasticity modulus E, and hence better strength characteristics of a particular soil layer and vice versa, while the moisture content and soil density did not show any obvious pattern and requires additional verification on the construction site. Finally, a geotechnical map was built for the driven piles and the optimal variations in the pile length for each zone were determined.

scholarly journals Limitations of the Danish driving formula for short piles

2021 ◽  
Vol 44 (2) ◽  
pp. 1-6
Author(s):  
Silvio Heleno de Abreu Vieira ◽  
Francisco R. Lopes
Keyword(s):  
Load Capacity ◽  
Precast Concrete ◽  
Free Fall ◽  
Technical Note ◽  
Driven Piles ◽  
Concrete Piles ◽  
Load Tests ◽  
Semi Empirical ◽  
The City ◽  
Pile Length

Dynamic formulae are a widely used expedient for the control of driven piles to ensure load capacity. These formulae have considerable limitations when used in the prediction of the load capacity on their own, but are very useful in the control of a piling when combined with other tests. This technical note presents an evaluation of the Danish Formula for 54 precast concrete piles, comparing its results with High Strain Dynamic Tests (HSDTs), Static Load Tests (SLTs) and predictions by a semi-empirical static method (Aoki & Velloso, 1975). The data used in the comparison come from three works in the city of Rio de Janeiro, Brazil. All piles were driven with free-fall hammers and in one particular work the piles were relatively short. The predictions of the Danish Formula were evaluated in relation to the pile length/diameter ratio. It was concluded that for short piles - with lengths less than 30 times the diameter - this formula indicates bearing capacities higher than the actual ones. A correction for a safe use of the Danish Formula for short piles is suggested.

scholarly journals Design Charts for Axially Loaded Single Pile Action

2019 ◽  
Vol 5 (4) ◽  
pp. 922-939 ◽  
Author(s):  
Anis Abdul Khuder Mohamad Ali ◽  
Jaffar Ahemd Kadim ◽  
Ali Hashim Mohamad
Keyword(s):  
Clay Soil ◽  
Skin Resistance ◽  
Soft Clay ◽  
Single Layer ◽  
Load Test ◽  
Engineering Properties ◽  
Single Pile ◽  
Dense Sand ◽  
Design Charts ◽  
Pile Length

The objective of this article is to generating the design charts deals with the axially ultimate capacity of single pile action by relating the soil and pile engineering properties with the pile capacity components. The soil and are connected together by the interface finite element along pile side an on its remote end.  The analysis was carried out using ABAQUS software to find the nonlinear solution of the problem. Both pile and soil were modeled with three-dimensional brick elements. The software program is verified against field load-test measurements to verify its efficiency accuracy. The concrete bored piles are used with different lengths and pile diameter is taken equals to 0.6 m. The piles were installed into a single layer of sand soil with angles of internal friction (20° t0 40°) and into a single layer of clay soil with Cohesion (24 to 96) kPa.  The getting results showed that for all cases study the total compression resistance is increased as pile length increased for the same property of soil, also illustrious that the total resistance of same pile length and diameter increased as the soil strength increasing. In addition, the same results were obtained for the end bearing resistance, skin resistance and tension capacity. Design charts were constructed between different types of soil resistance ratio and the pile length/diameter ratio (L/D) for all cases of study. One of improvement found from these curves that it is cheaply using piles of larger diameter than increasing their lengths for dense sand and to increasing piles lengths for loose sand. Moreover, it is inexpensively using piles of larger length in soft clay soil than increasing their diameter and piles of larger diameter in firm and stiff clay soils than increasing their length.

Finite Element Analysis of Bridge-Foundation Interaction System under Horizontal Seismic Excitation

2014 ◽  
Vol 490-491 ◽  
pp. 691-694
Author(s):  
Shou Long Chen ◽  
Chun Yi Cui ◽  
Yan Sun
Keyword(s):  
Finite Element ◽  
Seismic Waves ◽  
Soil Depth ◽  
Soft Soil ◽  
Soil Layer ◽  
Element Analysis ◽  
Interaction System ◽  
Frequency Components ◽  
Bridge Foundation ◽  
Pile Length

Based on Newmark-β gradual integration method and elastic-plastic mechanical theory, numeriacl analyses of effects of soft soil depth and thickness and pile length on the characteristics of horizontal seismic response of bridge-foundation interaction system with soft layers conducted by using finite element program Midas/GTS. The numerical results show that: (1) The high frequency components of seismic excitations can be filtered and the low frequency components are amplified correspondingly when seismic waves are transmitted through soft soil layer, and thicker and lower soft soil layer can amplified this effects; (2)The extremum force of abutment shows decreases first then increases with depth decreasing, and displacement of abutment top and bottom has the same law with seismic waves, and the thicker and lower soft soil layer or shorter piles can aggravate abutment force and deformation; (3)Shear extremal stress shows decrease from top to bottom and the thicker and lower soft soil layer or shorter piles are adverse on piles; (4)Moment extremal expresses first increase then decrease with pile length and the lower and thicker soft soil layer or shorter piles can enlarged piles moment.

scholarly journals PHYSICO-MECHANICAL, THERMAL AND ELECTRICAL CHARACTERISTICS COMPOSITE MATERIALS BASED ON POLYURETHANE BINDER AND MINERAL FILLERS

2020 ◽  
pp. 14-21
Author(s):  
V. Sh. Sulaberidze ◽  
E. A. Skorniakova
Keyword(s):  
Composite Materials ◽  
Flame Retardants ◽  
Mechanical Characteristics ◽  
Elasticity Modulus ◽  
Electrical Characteristics ◽  
Dielectric Coatings ◽  
Fine Powders ◽  
Coefficient Of Elasticity ◽  
Mineral Fillers ◽  
Physical And Mechanical Characteristics

The article presents the results of studies of the physical, mechanical, thermal and electrical characteristics of composite materials based on polyurethane as a binder and mineral fillers from fine powders AlN, Al(OH)3, SiO2, CaSiO3 with a content of up to 70 wt.%. These composite materials are used to create modern sealants and dielectric coatings that meet special requirements for strength, elasticity, heat resistance, including those that do not support combustion (by using flame retardants). Dependences of tensile strength, coefficient of elasticity, modulus of elasticity under compression and hardness of samples, electrical resistivity and thermal conductivity on the mass content of the filler were determined. It was found that in terms of the combination of physical and mechanical characteristics, the compositions based on the applied polyurethane are more durable, elastic and resilient than compositions based on a silicone binder with the same fillers previously studied by the authors.

scholarly journals Assessment of rockfall hazard on the steep-high slopes: Ermenek (Karaman, Turkey)

2016 ◽  
Author(s):  
Hidayet Taga ◽  
Kıvanç Zorlu
Keyword(s):  
Engineering Properties ◽  
Climatic Effects ◽  
Danger Zone ◽  
Safety Measures ◽  
Rockfall Hazard ◽  
Source Areas ◽  
Rock Bolting ◽  
Northern Side ◽  
The City

Abstract. Ermenek is one of the curious settlement areas because of its topographical features in Karaman (Turkey). The city is located in northern side of the very steep cliffs formed byjointed limestone which are suddenly increased from 1250 m to 1850 m. Moreover, these cliffs having almost 90° slope dip are the main rockfall source areas due to their lithologicalcharacteristics, climatic effects and engineering properties of rock units. Up to now, depending on rockfall events, almost 500 residences were damaged severely, and losses oflives were also recorded in Ermenek. The rockfall phonemon are initiated by discontinuities, lithological changes, weathering and freeze-thaw process in the study area. In this study,extensive fieldwork including determination of location and dimension of hanging, detached and already fallen blocks, a detailed discontinuity survey, description of geological,morphological and topographical characteristics was performed. Besides, rockfall hazard is evaluated by two-dimensional rockfall analyses along 10 profiles. During the rockfallanalyses; run out distance, bounce height, kinetic energy and velocity of various size of blocks for each profiles are determined by using RocFall v4.0 software. The results obtainedfrom rockfall analyses were used to map the areas possible rockfall hazard zones and rockfall source areas were interpreted. According to rockfall analysis, field study and laboratory testing, protective and preventiverecommendations can be suggested for the areas under rockfall threat. But, the most widely- known remedial measures in literature such as trenches, retaining walls (barrier), wiremeshes, cable/streching nets and rock bolting etc. are not sufficient in the study area, due to topographical, atmospheric and lithological features. For these reasons, firstly total evacuation of the danger zone should be applied and then hanging blocks in the reachablelocations can be removed taking safety measures in this area to make it safer for the living people.

scholarly journals ENGINEERING GEOLOGICAL ASPECTS FOR THE MICROZONATION OF THE CITY OF VOLOS, GREECE

2017 ◽  
Vol 43 (3) ◽  
pp. 1104
Author(s):  
A. A. Antoniou ◽  
G. Tsiambaos
Keyword(s):  
Seismic Hazard ◽  
Management System ◽  
Database Management ◽  
Classification Criteria ◽  
Database Management System ◽  
Strong Earthquakes ◽  
Seismic Code ◽  
Geotechnical Database ◽  
Geological Conditions ◽  
The City

The city of Volos located at the foot of the Peninsula of Pelion at Central Greece experienced several strong earthquakes during the previous century. The engineering geological conditions of the city have been analyzed using a relational geotechnical database management system, while the city subsoil has been grouped into five geotechnical units. The maps showing the contours of the depth to bedrock head and the ground zoning against seismic hazard were compiled through GIS. For the compilation of the latter map, a set of unified classification criteria was proposed based on the Greek Seismic Code (EAK 2000).

scholarly journals Study on the Bearing Capacity and Engineering Performance of Aeolian Sand

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Han Xia ◽  
Jingtao Zhang ◽  
Jun Cai ◽  
Huangsong Pan ◽  
Xuesen She
Keyword(s):  
Bearing Capacity ◽  
Soil Structure ◽  
Soil Layer ◽  
Aeolian Sand ◽  
Mu Us Desert ◽  
Large Numbers ◽  
Loose Soil ◽  
Load Tests ◽  
Physical And Mechanical Characteristics

The climate in the aeolian desert has great differences from that in other regions, generally showing large diurnal temperature differences and extremely dry and low groundwater level characteristics. Therefore, the physical and mechanical characteristics of the sand are different from those of other regions, and it has a loose soil structure, large pores, and a low bearing capacity. To ensure the security and applicability of engineering, it is necessary to study the engineering characteristics of aeolian sand. This paper focuses on the bearing capacity parameters of aeolian sand in the Mu Us Desert, and test sites in 6 weak foundation areas are selected. Large numbers of basic soil mechanical parameters have been collected through in situ static load tests (SLT) and laboratory confined compaction tests (CCT) to evaluate the effect of foundation treatments. The results show that the characteristics of aeolian sand in the Mu Us Desert include low moisture, poor cohesion, and easy compaction. The mud and water content affect the bearing capacity of aeolian sand. For weak foundations, adding a geogrid or replacing a weak soil layer with stone and aeolian sand can significantly improve the bearing capacity.

scholarly journals Surabaya earthquake hazard soil assessment

2020 ◽  
Vol 156 ◽  
pp. 02001
Author(s):  
Firman Syaifuddin ◽  
Amien Widodo ◽  
Dwa Desa Warnana
Keyword(s):  
Active Fault ◽  
Soft Soil ◽  
Soil Layer ◽  
Earthquake Hazard ◽  
The North ◽  
Seismic Amplification ◽  
Liquefaction Index ◽  
Index Value ◽  
The City ◽  
Site Classes

The vulnerability of land in an area to earthquake ground motions is one of the factors causing damage caused by the earthquakes. The city of Surabaya, which is crossed by two active fault segments, needs an assessment to reduce the risk of being affected by an earthquake that might occur. The aims of this study are (1) to find out the distribution of Seismic Site Classes, (20 to know the distribution of the value of Seismic Amplification, and (3) to know the potential of liquefaction in the city of Surabaya. Surabaya city, which is geologically dominated by alluvium deposits, consists of soft soil (SE) and medium (SD) sites based on N-SPT30 and Vs30 data. The level of soil amplification against earthquakes ranging from 1 to 4. This occurs because the physical properties of the Surabaya City soil layer are dominated by alluvium deposits. Regions with more than 2 amplification values are located around the coastline on the North and East coasts of Surabaya City. Based on the potential liquefaction index value, Surabaya City is included in the region with a high potential for liquefaction with a potential liquefaction index value of more than 5.

Study on the Engineering Properties of Saturated Red Sandstone

2014 ◽  
Vol 638-640 ◽  
pp. 589-593
Author(s):  
Hong Yi Wang ◽  
Wu Xiu Ding ◽  
Jin Jin Yang
Keyword(s):  
Construction Projects ◽  
Elasticity Modulus ◽  
Triaxial Compression ◽  
Mechanical Damage ◽  
Confining Pressure ◽  
Peak Strength ◽  
Engineering Properties ◽  
Compression Tests ◽  
Red Sandstone ◽  
Slope Excavation

Red sandstone with a strong water softening can cause difficulties of construction projects, especially for slope excavation and support engineering. Therefore, the study on the engineering properties of saturated red sandstone has a important meaning. The mechanical parameters of saturated red sandstone are obtained by the triaxial compression tests. The test results indicate that the ralations between peak strength, elasticity modulus and confining pressure for the saturated specimens are similar with the natural specimens, that is, with the increasing of confining pressure, the peak strength and the elasticity modulus will increase, but the growth rate becomes slowly. Under the same confining pressure, the peak strength and the elasticity modulus of saturated specimen are more smaller than the natural one. The mechanical damage caused by water recedes when the confining pressure increases, so for the geotechnical engineering with larger influence of water, the increasement of confining pressure by the supporting structures is conducive to the stability of rock mass. The research results will provide a theoretical basis for the red sandstone engineering.

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