scholarly journals CPT Parameters of Loess Subsoil in Lublin Area

2021 ◽  
Vol 11 (13) ◽  
pp. 6020
Author(s):  
Krzysztof Nepelski ◽  
Agnieszka Lal
Keyword(s):  
Water Content ◽  
Building Structures ◽  
Load Bearing ◽  
Engineering Research ◽  
Loess Soils ◽  
Epigenetic Processes

Loess soils were created by the wind transporting particles with later or in parallel occurred protogenetic, syngenetic and epigenetic processes. As a result, various genetic processes affected loesses strength and deformability characteristics. The aim of the study is to estimate the main CPT parameters of loess subsoil in Lublin area according to divided facies. The subsoil in the area of the Nałęczowski Plateau, where Lublin is located, consists mainly of loess from aeolian and aeolian–diluvial facies, and in the deeper parts—from aeolian–alluvial facies. Most of the results obtained for the aeolian facies at the level of qc in the range from 4.5 to 8.0 MPa indicate that these soils are a good load-bearing substrate for building structures. Cone resistances mostly at the level of 1.5–4.0 MPa for the diluvial and alluvial facies confirm that these facies constitute less favorable foundation conditions. The reduced resistance results mainly from the increased water content in ground pores. It is especially the soils of the diluvial facies that provide unfavorable foundation conditions, as they occur near the surface. Genetic processes are a very important element that should be taken into account in engineering research.

STRENGTHENING SUPPORTING COLUMNS WITH CARBON CONCRETE

2021 ◽  
Vol 95 (3) ◽  
pp. 59-67
Author(s):  
K. HOLSCHEMACHER ◽  
◽  
A.G. BULGAKOV ◽  
W. POLIENKO ◽  
◽  
...  
Keyword(s):  
Composite Material ◽  
Building Materials ◽  
Point Load ◽  
Geometrical Parameters ◽  
Building Structures ◽  
Technical School ◽  
Load Bearing ◽  
Floor Slabs ◽  
Wide Range ◽  
The Subject

Textile concrete is an innovative composite material that has been the subject of intensive research since the beginning of the 90s of the last century. After the approval of the rules and regulations on its application to strengthen floor slabs, an important step was taken towards its entry into the building materials market. Questions regarding the reinforcement of rod-shaped load-bearing elements of building structures need additional research. Despite the great potential available, the method of tying load-bearing supports and columns is still not well understood. There is a need for research on a wide range of geometric parameters and the reinforcement systems used. The Institute of Reinforced Concrete of the Higher Technical School in Leipzig tested various samples of carbon-reinforced samples in a wide range of geometrical parameters. Their goal was to assess the effect on a possible increase in the bearing capacity of carbon-reinforced columns at a concentrated point load.

The experimental study of glass multilayer columns using digital image correlation

2019 ◽  
Vol 1 (96) ◽  
pp. 32-41
Author(s):  
B. Demchyna ◽  
M. Surmai ◽  
R. Tkach
Keyword(s):  
Experimental Study ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Building Structures ◽  
Load Bearing ◽  
Regulatory Documents ◽  
Triplex Glass ◽  
Calculation Methodology ◽  
Glass Columns

Purpose: The purpose of the research is to study the deformability of glass multilayer columns at the central compression using digital image correlation. It becomes possible to use the method of digital image correlation for the experimental study of load bearing building structures of glass. Design/methodology/approach: The approach which has been used to solve the above problems is to conduct an experimental study of glass columns on central compression, in which deformations were measured using digital image correlation. Findings: The possibility of using load bearing building structures of glass triplex has been discovered. A program of experimental studies was developed. It included the testing of prototype samples on central compression with rigid fastening. On the basis of the obtained results, a graph of dependence of relative deformations on normal tension, graphs of the dependence of the bending of columns on load in different planes, and a modulus of elasticity of triplex glass have been determined. Research limitations/implications: The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass increases their cost, since each project is individual and requires the experimental research. Practical implications: Using the approaches developed in the paper, the method of digital image correlation, which is to measure deformations when testing glass structures on central compression can be applied. Originality/value: The experimental study is probably the first one in which deformations of glass columns are determined using the method of digital image correlation, so it is new and original. The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass, increases their cost, since each project is individual and requires the experimental research.

Improving the Mechanical Properties in Tissue Engineered Scaffolds

2008 ◽  
Author(s):  
M. T. Arafat ◽  
M. M. Savalani ◽  
I. Gibson
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Threshold Value ◽  
Hole Diameter ◽  
Fused Deposition Modelling ◽  
Load Bearing ◽  
Engineering Research ◽  
Fused Deposition ◽  
Low Load ◽  
Through Hole

Scaffold-based tissue engineering research aims to aid in the repair and regeneration of bone defects. Scaffolds act as a basis for carrying cells or therapeutic agents for regenerative therapies. To achieve this, the scaffold should have appropriate osteoconductive, osteoinductive and biodegradable properties. To date, such structures have only been used with some success in low-load bearing applications, despite the large variety of biomaterials and fabrication techniques explored in the last two decades. Previous studies have illustrated the suitability of the Fused Deposition Modelling (FDM) process in fabricating PCL-20% β-TCP scaffolds for low-load bearing bone tissue engineering applications. This paper aims to demonstrate the possibility of increasing the mechanical properties of such scaffolds by introducing a through-hole. In addition, it is conjectured that such through-holes may also become useful for the channeling or storage of nutrients. A number of scaffolds with through-holes of various sizes were fabricated in order to study the effect of the through-hole diameter on the modulus (stiffness) of the complete scaffold. It was observed that the stiffness of the scaffolds varies with the diameter of the through-hole. After a certain through-hole diameter threshold the stiffness of the scaffold begins to increase above that of the original scaffold. An improvement of approximately 37% was observed in the PCL-20% β-TCP scaffolds. Also, it was noted that the threshold value for the through-hole diameter depends on the spacing of the adjacent filaments of the scaffolds.

scholarly journals Stress-strain state of the building foundations with taking into account the possible water saturation of loess soils

2020 ◽  
pp. 22-31
Author(s):  
Veronika Zhuk ◽  
Oleksandr Piatkov ◽  
Sergiy Tarambula
Keyword(s):  
Strain State ◽  
Water Saturation ◽  
Cost Effective ◽  
Loess Soil ◽  
Soil Base ◽  
Stress Strain ◽  
Engineering Structures ◽  
Load Bearing ◽  
Stress Strain State ◽  
Loess Soils

In Ukraine, the problem of construction on loess soils is relevant due to the widespread use of these soils and their negative property - the ability to give additional deformations of subsidence during water saturation. Flooding of territories by groundwater, emergency leaks from aquifers cause significant problems during the exploitation of buildings and engineering structures on such soils. Computer simulation of the interaction of the building with the soil base allows to investigate the influence of all negative factors on the change of the stress-strain state of both the soil base and the load-bearing structures of the building. The study of the interaction of the building with the foundation was performed using the software package LIRA-CAD. The interaction of the building with the soil base, the soils of which are able to reduce their mechanical properties with increasing humidity and give additional subsidence deformations, was studied. A variant design of the foundations was performed taking into account the occurrence of uneven deformations during subsidence of the loess soil due to its moistening in case of possible emergency losses from aquifers. The change of stress-strain state of the foundations of the building depending on the spatial rigidity of the foundation, the location of the soaking zone within the building spot, the shape and size of the zone of soil moisture is analyzed. It is shown that taking into account the possible water saturation of loess soils when calculating the collaborate of the building with the soil base, allows to obtain stress-strain state of foundations and load-bearing structures of the aboveground part of the building for the most unfavorable conditions that may occur. The search for the optimal variant of the foundation structures of the building, which, while remaining cost-effective, provides reliable operation of the building in conditions of possible occurrence of uneven deformations of subsidence of the soil base during water saturation of the layer of loess soils. According to the research results, a rational variant of the foundation structures has been designed taking into account the possible occurrence of non-uniform deformations.  

scholarly journals Performance of Soil Water Content Using Ground Penetrating Radar with Different Antenna Frequencies

2018 ◽  
Vol 7 (2.29) ◽  
pp. 815
Author(s):  
Nurul Izzati Abd Karim ◽  
Samira Albati Kamaruddin ◽  
Rozaimi Che Hasan
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Ground Penetrating Radar ◽  
Peat Soil ◽  
Relative Dielectric Permittivity ◽  
Depth Of Penetration ◽  
Engineering Research ◽  
Ground Penetrating

Accurate measurements of Soil Water Content (SWC) with applicable and relevant support are essential in many fields of earth and soil engineering research. Ground Penetrating Radar (GPR) is a geophysical tool that measures and provides accurate results for determination of the SWC. To prove the accuracy of SWC measurement using GPR, a field survey was performed in peat soil. This paper presents a fieldwork survey with the aim of assessing the SWC measurement using GPR. The survey work was conducted at Johor Bharu using different antenna frequencies (250 and 700 MHz). Five profiles, which is 5m by 5m in length, were scanned along an east-west direction with a common offset at an equal spacing of 1m.  To measure the SWC using GPR, the researchers used the velocity from the GPR’s signal from the receiving antenna to the soil. Statistical analysis was carried out based on the dielectric permittivity and SWC. Schaap’s equation and Roth’s equation were used to distinguish the relative dielectric permittivity of the soil to SWC. The results of this study show the linear function,  for the measured SWC. The validation graph shows that at a frequency of 250 MHz, the depth of penetration was greater compared to the frequency of 750 MHz. These results, suggest that a higher frequency will give higher resolution but lower depth penetration.  

Narrow Reinforced Concrete Slabs after their Flexural Destruction

2014 ◽  
Vol 969 ◽  
pp. 271-275 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
The Self ◽  
Concrete Slabs ◽  
Building Structures ◽  
Reinforcing Steel ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Horizontal Shift ◽  
Reinforced Concrete Slabs

In the course of the exploitation of building structures frequently situations turn up, in which the structure is not adequately used (it may, for instance, be exposed to considerably greater loads than previously been intended). In the state of an unforeseen overload of the structure, essential reserves of their load-bearing capacity may be disclosed in the case of the self-acting work as a flexible strand. The paper presents the results of investigations concerning the influence of the parameters of reinforcing steel on the mechanism of the destruction of six single-span models of narrow reinforced concrete slabs, in which a horizontal shift of the supports was not possible. The tests were carried out on narrow slabs with the dimensions 3860×480×100 mm. The results of the tests were compared with analytical calculations.

scholarly journals Investigation of effect of water content on railway granular supplementary layers

2021 ◽  
pp. 64-68
Author(s):  
S Fischer
Keyword(s):  
Bearing Capacity ◽  
Water Content ◽  
Road Construction ◽  
High Water ◽  
Shear Resistance ◽  
The Other ◽  
High Water Content ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Rock Mining

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different samples were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multi-level shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road products have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

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