scholarly journals The Use of Geotechnical Methods to Determine the Deformation Parameters of the Ground in Terms of Operation and Safety of Mortar Use

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7237
Author(s):  
Grzegorz Bartnik ◽  
Kazimierz Józefiak ◽  
Małgorzata Superczyńska ◽  
Magdalena Czerwińska ◽  
Witold Krajewski ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Field Tests ◽  
Research Problem ◽  
Measurement Methods ◽  
Geotechnical Parameters ◽  
Firing Test ◽  
Deformation Parameters ◽  
Different Types ◽  
Load Tests ◽  
Clear Description

During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of terrains on its strength and work during shooting should be examined. Until now, in the Polish standardization documents there was no clear description of the ground parameters used for these kinds of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of ground and its geotechnical parameters. In view of the above, it has become important to draw up a research problem in the form of determining the types of soil with parameters, enabling the mortar tests to be carried out in conditions as close as possible to combat conditions. Therefore, the authors carried out the theoretical calculations and field tests with the use of geotechnical methods such as static and dynamic load tests to determine the parameters of the ground for mortar testing. Preliminary tests were conducted using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the tested methods of measuring the parameters of soil compressibility were determined.

scholarly journals The Use of Geotechnical Methods to Determine the Strength Parameters of the Substrate in Terms of Operation and Safety of Mortar Use

2021 ◽  
Author(s):  
Grzegorz Bartnik ◽  
Kazimierz Józefiak ◽  
Małgorzata Superczyńska ◽  
Magdalena Czerwińska ◽  
Witold Krajewski ◽  
...  
Keyword(s):  
Research Methods ◽  
Experimental Analysis ◽  
Measurement Methods ◽  
Strength Parameters ◽  
Geotechnical Parameters ◽  
Firing Test ◽  
Different Types ◽  
Soil Compressibility ◽  
Clear Description

Abstract: During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of substrate on its strength and work during shooting should be examined. Until now in the Polish standardization documents was no clear description about the substrate parameters used for this kind of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of substrate and its geotechnical parameters. Therefore, the authors carried out analytical and experimental analysis of the use of geotechnical methods to determine the parameters of the substrate for mortar testing. The paper presents the proposed types of standardized soil and their research methods. Preliminary tests were also carried out using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the proposed methods of measuring the parameters of soil compressibility were determined.

scholarly journals Experimental and numerical analysis of foundation pilings partially embedded in rock

2013 ◽  
Vol 66 (4) ◽  
pp. 439-446
Author(s):  
Jean Rodrigo Garcia ◽  
Paulo José Rocha de Albuquerque ◽  
Rodrigo Álvares de Araújo Melo
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Field Tests ◽  
Soil Surface ◽  
Residual Soil ◽  
Geotechnical Parameters ◽  
Weathered Rock ◽  
Load Tests ◽  
Geotechnical Design ◽  
Transfer Method

The behaviours of four foundation pilings (ϕ=0.41 m) constructed in Foz do Iguaçu, Paraná (PR), Brazil and subjected to slow loading tests were analysed. The results were compared with results from three-dimensional numerical modelling using the finite element method, which facilitates simulation of the elasto-plastic behaviour of soil. The local subsoil comprises varied stratigraphies; it is composed of a residual soil surface layer followed by weathered rock and bedrock, which are a few meters deep. The massif geotechnical parameters were determined through correlations obtained from field tests, whereby the values for cohesion, angle of friction, modulus of deformability and uniaxial compressive strength in the different subsoil layers were estimated. The load tests were interrupted at 3000 kN and displaced by less than 5 mm in the working load (1500 kN). The pilings were subjected to lateral friction work with an average stress of approximately 70 kPa for the surface portion (residual soil) and greater than 150 kPa for the weathered rock portions. The estimated geotechnical parameters provided values that were an exact match with the numerical analyses. Thus, given the analyses and load transfer method, the piling lengths can be reduced, which will facilitate the optimisation of the geotechnical design.

scholarly journals Analysis of displacement of excavation based on inclinometer measurements

2012 ◽  
Vol 34 (4) ◽  
pp. 3-16 ◽  
Author(s):  
Karolina Gorska ◽  
Marek Wyjadłowski
Keyword(s):  
Theoretical Calculations ◽  
Back Analysis ◽  
Field Measurements ◽  
Soil Medium ◽  
Geotechnical Parameters ◽  
Angle Of Internal Friction ◽  
Material Parameters ◽  
Bored Pile ◽  
Excavation Process ◽  
Excavation Support

Abstract The article presents back analysis to estimate geotechnical parameters of fill layer. The agreement between field measurements and theoretical calculations was examined. Displacements of a cantilever CFA bored pile wall were monitored. The inclinometric measurements were taken directly after pile construction and according to excavation process. Over 200 calculation series were performed, with changing fill parameters. The calculations employed the actual geometric and material parameters of the pile wall, as well as geotechnical parameters of layered soil. The parameters estimated through back analysis were the angle of internal friction and Young’s modulus of fill layer. In the case discussed, pile wall cap displacement was the response of the system, and soil medium parameters were the input data. The agreement between theoretical calculations and inclinometer measurements was assessed in accordance with two functions. The measured horizontal displacements of excavation support structure assumed different values at the two inclinometer sites analysed. Back analysis results for these sites are approximately convergent for a final excavation depth.

scholarly journals State-of-the-Art-Review of Collapsible Soils

2000 ◽  
Vol 5 ◽  
pp. 115 ◽  
Author(s):  
A. A. AL-Rawas
Keyword(s):  
Field Tests ◽  
Clay Content ◽  
Field Testing ◽  
Dry Density ◽  
Foundation Design ◽  
Treatment Methods ◽  
Collapse Potential ◽  
Collapsible Soils ◽  
Different Types ◽  
Compaction Control

Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.

scholarly journals Researched the wear resistance of hardened plowshares by electroarc and spot welding

2019 ◽  
pp. 189-196
Author(s):  
M. Vаsylenko ◽  
D. Buslаiev ◽  
O. Kаlinin ◽  
Yu. Kononogov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Spot Welding ◽  
Field Tests ◽  
Sandy Soils ◽  
Clay Soils ◽  
Basic Principles ◽  
Data Field ◽  
Different Types ◽  
Analytical Processing

Purpose. The researched of the wear resistance of hardened plowshares by electroarc and abrasion-resistant electrodes, when they are used in soils of different types. Methods. Conducting and planning an experiment, mathematical statistics and analytical processing of experimental data, field tests of experimental plowshares using the basic principles of the theory of friction and abrasive wear. Results. The characteristic defects of shares operating in different types of soils are determined. According to the proposed hardening technology, the wear rate of experimental shares is reduced. Conclusions 1.It has been established that the nature of the parts of tillage machines wear is significantly different when operating on various types of soils. 2.It was found that the wear rate of hardened plowshares for sandy soils is 1.2–1.6 times less than that of serial parts; hardened plowshares for clay soils also have a wear rate of 1.2–1.3 times less than serial ones. Keywords: exploitation, hardfacing, plowshares, soils of different types, wear, wear resistance.

scholarly journals Analysis on Loose Circle of Surrounding Rock of Large Deformation Soft-Rock Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Rui Wang ◽  
Yiyuan Liu ◽  
Xianghui Deng ◽  
Yu Zhang ◽  
Xiaodong Huang ◽  
...  
Keyword(s):  
Large Deformation ◽  
Theoretical Calculations ◽  
Rapid Development ◽  
Field Tests ◽  
Soft Rock ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Distribution Law ◽  
Geological Conditions ◽  
Rock Tunnel

With the rapid development of tunnel construction in China, deep buried and long tunnel projects are emerging in areas with complex engineering geological conditions and harsh environment, and thus large deformation of tunnels under conditions of high in situ stress and soft rock becomes increasingly prominent and endangers engineering safety. Therefore, it is of great significance to control the deformation and improve the stability of surrounding rock by analyzing the thickness and distribution law of loose circle according to the unique mechanical properties and failure mechanism of surrounding rock of large deformation soft-rock tunnel. Based on unified strength theory, this paper deduces the radius calculation formula of the loose circle by considering the influence of intermediate principal stress. Furthermore, the theoretical calculations and field tests of the loose circle in the typical sections of grade II and III deformation of Yuntunbao tunnel are carried out, and the thickness and distribution law of loose circle of surrounding rock of large deformation soft-rock tunnel is revealed. The results show that the formula based on the unified strength criterion is applicable for a large deformation tunnel in soft rock.

Modelling effects of pile diameter

2016 ◽  
Vol 53 (1) ◽  
pp. 173-178 ◽  
Author(s):  
W.D. Liam Finn ◽  
J. Dowling
Keyword(s):  
Small Diameter ◽  
Field Tests ◽  
Technical Note ◽  
American Petroleum Institute ◽  
Finite Element Program ◽  
Model Soil ◽  
Pile Diameter ◽  
Element Program ◽  
Load Tests ◽  
Diameter Effect

The most commonly used program for the analysis of piles under static lateral loading is LPILE. The program uses the nonlinear Winkler springs recommended by the American Petroleum Institute (API) to model soil–pile interaction. The p–y (load–displacement) curves were developed from field tests, with pile diameters in the range 0.324–0.67 m. When these p–y curves are used to analyze load tests on piles with larger diameters, the computed load–deflection curves underestimate the stiffnesses of the test piles. This effect is referred to as the pile diameter effect. In this technical note, a very different approach is presented to evaluate the pile diameter effect. Both LPILE and a continuum-based finite element program VERSAT-P3D were calibrated to closely simulate the results of two lateral load tests on small-diameter piles at two different sites. VERSAT-P3D modelled the volume of the pile and LPILE did not. Each program was used to develop p–y curves for increasingly larger pile diameters up to 2.0 m. An important finding for practice is that there was no pile diameter effect for displacements up to 60 mm. LPILE can be used with confidence in practice in this displacement range. Thereafter, the load–deflection curves from LPILE became softer and the pile diameter effect became evident.

scholarly journals Elderly Fall Detection with an Accelerometer Using Lightweight Neural Networks

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1354 ◽  
Author(s):  
Gaojing Wang ◽  
Qingquan Li ◽  
Lei Wang ◽  
Yuanshi Zhang ◽  
Zheng Liu
Keyword(s):  
Neural Networks ◽  
Computational Cost ◽  
Fall Detection ◽  
The Elderly ◽  
Research Problem ◽  
Wearable Devices ◽  
The Past ◽  
Machine Learning Methods ◽  
Open Research ◽  
Different Types

Falls have been one of the main threats to people’s health, especially for the elderly. Detecting falls in time can prevent the long lying time, which is extremely fatal. This paper intends to show the efficacy of detecting falls using a wearable accelerometer. In the past decade, the fall detection problem has been extensively studied. However, since the hardware resources of wearable devices are limited, designing highly accurate embeddable models with feasible computational cost remains an open research problem. In this paper, different types of shallow and lightweight neural networks, including supervised and unsupervised models are explored to improve the fall detection results. Experiment results on a large open dataset show that the lightweight neural networks proposed have obtained much better results than machine learning methods used in previous work. Moreover, the storage and computation requirements of these lightweight models are only a few hundredths of deep neural networks in literature. In tested lightweight neural networks, the best one is proved to be the supervised convolutional neural network (CNN) that can achieve an accuracy beyond 99.9% with only 441 parameters. Its storage and computation requirements are only 1.2 KB and 0.008 MFLOPs, which make it more suitable to be implemented in wearable devices with restricted memory size and computation power.

Full-scale field tests on directly embedded steel pole foundations

2000 ◽  
Vol 37 (2) ◽  
pp. 414-437 ◽  
Author(s):  
Asim Haldar ◽  
VSN Prasad Yenumula ◽  
T R Chari
Keyword(s):  
Field Tests ◽  
Ground Level ◽  
Full Scale ◽  
Design Parameters ◽  
Embedment Depth ◽  
Ultimate Capacity ◽  
Backfill Material ◽  
Different Types ◽  
Full Scale Tests ◽  
Laterally Loaded

The results of eight full-scale tests on directly embedded steel pole foundations are presented. Fully instrumented poles were tested to measure the various design parameters. Different types of backfills such as sand, in situ gravelly sand, crushed stone, and flowable material were used. Various parameters were measured, including applied moment, ground line deflection-rotation, rotation of the pole below the ground level, soil pressures, and bending moments in the poles. The behaviour of these foundations was explained through ultimate capacity and moment-rotation characteristics. Based on these test results, it was found that the capacity of the directly embedded pole foundation depends primarily on the compaction levels of backfill and the embedment length of the pole. Flowable backfill material, which does not require any compaction, was found to be most effective and promising. Even when the backfill was loose, the lateral capacity significantly increased by the addition of a baseplate or by installing the pole with an additional embedment depth. Various theories developed for laterally loaded rigid piles were used to predict the moment-rotation behaviour and the ultimate capacity of the directly embedded pole foundation with different types of backfill material. Results from the analytical investigations were compared with those obtained from the full-scale load tests. Comparisons show that the ultimate capacities predicted by the models ranged from 0.30 to 2.20 times the measured capacities.Key words: backfill, compaction, full-scale tests, laterally loaded rigid piles, transmission steel poles, ultimate moment.

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