Studia Geotechnica et Mechanica最新文献

Correlation between Cone Penetration Test parameters, soil type, and soil liquidity index using long short-term memory neural network 基于长短期记忆神经网络的探深试验参数、土壤类型和土壤流动性指标的相关性研究

Studia Geotechnica et Mechanica Pub Date : 2023-11-13 DOI: 10.2478/sgem-2023-0023

Mateusz Jocz, Marek Lefik

引用次数: 0

Second-order effects in horizontally loaded reinforced concrete columns 水平荷载下钢筋混凝土柱的二阶效应

Studia Geotechnica et Mechanica Pub Date : 2023-11-02 DOI: 10.2478/sgem-2023-0022

Janusz Pędziwiatr, Michał Musiał

引用次数: 0

Quality requirements for static liquefaction test of soil in triaxial apparatus 三轴仪土壤静态液化试验质量要求

Studia Geotechnica et Mechanica Pub Date : 2023-10-18 DOI: 10.2478/sgem-2023-0019

Mirosław J. Lipiński, Małgorzata Wdowska, Intan Puspitaningrum

引用次数: 0

Modernized Resonant Column and Torsional Shearing Apparatus With Multipoint Contactless Displacement Detection System 带多点非接触位移检测系统的现代化共振柱扭剪仪

Studia Geotechnica et Mechanica Pub Date : 2023-10-08 DOI: 10.2478/sgem-2023-0018

Marcin Bujko, Marta Bocheńska, Piotr Srokosz, Ireneusz Dyka

{"title":"Modernized Resonant Column and Torsional Shearing Apparatus With Multipoint Contactless Displacement Detection System","authors":"Marcin Bujko, Marta Bocheńska, Piotr Srokosz, Ireneusz Dyka","doi":"10.2478/sgem-2023-0018","DOIUrl":"https://doi.org/10.2478/sgem-2023-0018","url":null,"abstract":"Abstract In this study, a modification of resonant column/torsional shearing (RC/TS) apparatus was proposed to perform a qualitative analysis of a noncohesive soil specimen vibration during RC tests. An additional multipoint displacement detection system was installed in the RC/TS WF8500 device. In the new measuring system, 48 mini-magnets are attached to the side surface of a cylindrical soil specimen, creating a regular grid of measuring points. Around 48 Hall sensors (Honeywell SS495A1) are used to measure changes in the magnetic field strength due to the movement of the corresponding magnets on the surface of the specimen subjected to dynamic torque. The Hall sensor generates an analog signal that is proportional to the change in the magnetic field. The measurements are collected with a newly developed data acquisition system that consists of a set of analog-to-digital converters and a set of ARM (Advanced RISC (Reduced Instruction Sets Computing) Machine) microcontrollers. The measurement system is controlled with a dedicated software, ControlRec, developed by the authors. The measurements are taken synchronically with and independently from the standard RC test procedure. The new measuring technique allows to observe displacements of the 48 points on the specimens’ surface with over 4 times higher sampling rate than in the original measuring system. As a result, additional effects related to the mechanical wave propagation through soil specimen were observed (local disturbances in distribution of vibration amplitudes or significant displacements near the bottom end of the specimen, which is assumed to be fixed in the standard RC/TS results analysis), that could not be identified using the standard equipment of the device.","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135197434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reliability of Methods for Determination of Stress History Parameters in Soils 土壤应力历史参数测定方法的可靠性

Studia Geotechnica et Mechanica Pub Date : 2023-10-07 DOI: 10.2478/sgem-2023-0017

Małgorzata Wdowska, Mirosław J. Lipiński

{"title":"Reliability of Methods for Determination of Stress History Parameters in Soils","authors":"Małgorzata Wdowska, Mirosław J. Lipiński","doi":"10.2478/sgem-2023-0017","DOIUrl":"https://doi.org/10.2478/sgem-2023-0017","url":null,"abstract":"Abstract Stress history acquired by any cohesive soil influences, to a large extent, three groups of fundamental properties indispensable in geotechnical design i.e. state of soil, shear strength, and stiffness characteristics. The basic stress history parameter (from which other parameters are derived) determined directly from laboratory tests is a preconsolidation stress σ′p. Since the first method proposed by Casagrande in 1936, value σ′p is determined in the oedometer test as a border between overconsolidated (OC) and normally consolidated (NC) zones. Approach based on division between predominantly elastic, (recoverable) strain, and plastic (irrecoverable) strain is a main principle of several methods of σ′p determination, which have been proposed over the past eighty-six years. Accumulated experiences have revealed that any laboratory procedure based on the oedometer test does not provide realistic value of preconsolidation stress, especially in heavy preconsolidated soils. The major reason for that results from the fact that the mechanism responsible for natural overconsolidation is more complicated than mechanical preloading. Therefore, there is a necessity to reevaluate effectiveness of standard methods and look for another solution of evaluation yield stress σ′Y in natural soils. This article presents the comparison between σ′Y determined for various soils with use of standard methods based on conventional oedometer test and yield stress determined on the basis of alternative procedures. The latter are represented by various approaches as e.g. based on SHANSEP procedure or initial shear modulus and others. The most promising among these alternative methods is a new concept based on dilatancy phenomenon that takes place during shearing of a dense soil. The parameter reflecting stress history is derived from pore pressure response and is based on characteristic values of Skempton's parameter A record. Consistency of data concerning stress history parameters profile obtained for deep subsoil on the basis of various methods is shown for comparison.","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135253849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Soft Soil Samples Quality on the Compressibility and Undrained Shear Strength – Seven Lessons Learned From the Vistula Marshlands 软土试样质量对压缩性和不排水抗剪强度的影响——以维斯瓦湿地为例

Studia Geotechnica et Mechanica Pub Date : 2023-09-30 DOI: 10.2478/sgem-2023-0012

Jakub Konkol

{"title":"Influence of Soft Soil Samples Quality on the Compressibility and Undrained Shear Strength – Seven Lessons Learned From the Vistula Marshlands","authors":"Jakub Konkol","doi":"10.2478/sgem-2023-0012","DOIUrl":"https://doi.org/10.2478/sgem-2023-0012","url":null,"abstract":"Abstract This technical article presents the influence of sample quality on the compressibility parameters and undrained shear strength ( c u ) of soft soils from the Vistula Marshlands. The analysis covers: (1) quality of soft soil according to three criteria: void ratio (Δ e / e 0 index), volumetric strain (Δ ɛ v ) and C r / C c ratio; (2) influence of storage time on quality; (3) influence of sample quality on undrained shear strength ( c u ), and (4) reliability of compression and undrained shear strength parameters estimation. The sample quality of three different soft soils (peat, organic clays, and organic silts) was investigated using dataset of geotechnical investigations from the Vistula Marshlands. The reliability of oedometer tests and compressibility parameters determination was shown. Different undrained shear strength estimates (from lab and field tests) were juxtaposed with sample quality. In situ estimates of undrained shear strength were compared with results of triaxial tests and direct simple shear test on reconstituted samples as well as SHANSEP estimates. The results of research are grouped in seven lessons. The most important outcomes are: (1) the quality of samples is at best moderate or poor and there is no significant influence of storage time on sample quality, (2) regardless of testing method, the undrained shear strength natural variability of the Vistula Marshlands soft soils is between 20% and 50% depending on deposit depth and soil type, (3) the most accurate estimation of undrained shear strength can be obtained from field vane test (FVT) while unconsolidated, undrained compression (UUC) triaxial tests should be avoided, (4) SHANSEP approach can be considered as a valuable estimate of c u (next to the FVTs), which additionally allows in relatively easy way to establish lower and upper bounds of c u .","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136280609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compressive and Tensile Strength of Nano-clay Stabilised Soil Subjected to Repeated Freeze–Thaw Cycles 反复冻融循环作用下纳米粘土稳定土的抗压和抗拉强度

IF 0.6

Studia Geotechnica et Mechanica Pub Date : 2023-09-01 DOI: 10.2478/sgem-2023-0009

M. Roustaei, Mahdi Sabetraftar, E. Taherabadi, M. Bayat

{"title":"Compressive and Tensile Strength of Nano-clay Stabilised Soil Subjected to Repeated Freeze–Thaw Cycles","authors":"M. Roustaei, Mahdi Sabetraftar, E. Taherabadi, M. Bayat","doi":"10.2478/sgem-2023-0009","DOIUrl":"https://doi.org/10.2478/sgem-2023-0009","url":null,"abstract":"Abstract Improvement of the mechanical properties of clayey soils by additional elements to enhance the strength under numerous freezing and thawing cycles has been considered as a serious concern for engineering applications in cold regions. The objective of the current study is to investigate the effect of nano-clay as a stabiliser on the mechanical properties of clay. To this end, the clay specimens were prepared by adding various percentages of nano-clay ranging from 0.5% to 3% by dry weight of soil and were experimentally tested under the uniaxial compression and tensile splitting tests under different curing times (0, 7 and 28 days) after experiencing various freeze–thaw cycles ranging from 0 to 11. It can be concluded from the results that nano-clay particles may be used as a stabiliser in geotechnical applications to improve soil property. The results indicate that the optimum moisture content (OMC) of specimens increases and the maximum dry density (MDD) decreases with the increasing nano-clay content. The specimens containing about 1% nano-clay recorded maximum values of unconfined compressive strength (UCS) as well as tensile strength. For example, the addition 1% nano-clay increased the UCS and tensile values of clay specimens under the curing time of 28 days by 34% and 247%, respectively. In addition, the long-term durability of specimens against freeze–thaw cycles increases further with the addition of nano-clay content ranging from 2% to 3%.","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42793595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shell Deformation During the Construction of Record Span Soil-steel Buried Structure in Ras-Al-Khaimah (UAE) 阿拉伯联合酋长国Ras-Al-Khaimah纪录跨土钢埋地结构施工过程中的壳变形

Studia Geotechnica et Mechanica Pub Date : 2023-09-01 DOI: 10.2478/sgem-2023-0007

Czesław Machelski, Piotr Tomala

引用次数: 0

A Novel Method for Optimizing Parameters influencing the Bearing Capacity of Geosynthetic Reinforced Sand Using RSM, ANN, and Multi-objective Genetic Algorithm 基于RSM、ANN和多目标遗传算法优化土工合成砂承载力参数的新方法

IF 0.6

Studia Geotechnica et Mechanica Pub Date : 2023-05-31 DOI: 10.2478/sgem-2023-0006

Brahim Lafifi, A. Rouaiguia, E. Soltani

{"title":"A Novel Method for Optimizing Parameters influencing the Bearing Capacity of Geosynthetic Reinforced Sand Using RSM, ANN, and Multi-objective Genetic Algorithm","authors":"Brahim Lafifi, A. Rouaiguia, E. Soltani","doi":"10.2478/sgem-2023-0006","DOIUrl":"https://doi.org/10.2478/sgem-2023-0006","url":null,"abstract":"Abstract In this study, a novel method is proposed to optimize the reinforced parameters influencing the bearing capacity of a shallow square foundation resting on sandy soil reinforced with geosynthetic. The parameters to be optimized are reinforcement length (L), the number of reinforcement layers (N), the depth of the topmost layer of geosynthetic (U), and the vertical distance between two reinforcement layers (X). To achieve this objective, 25 laboratory small-scale model tests were conducted on reinforced sand. This laboratory-scale model has used two geosynthetics as reinforcement materials and one sandy soil. Firstly, the effect of reinforcement parameters on the bearing load was investigated using the analysis of variance (ANOVA). Both response surface methodology (RSM) and artificial neural networks (ANN) tools were applied and compared to model bearing capacity. Finally, the multiobjective genetic algorithm (MOGA) coupled with RSM and ANN models was used to solve multi objective optimization problems. The design of bearing capacity is considered a multi-objective optimization problem. In this regard, the two conflicting objectives are the need to maximize bearing capacity and minimize the cost. According to the obtained results, an informed decision regarding the design of the bearing capacity of reinforced sand is reached.","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":"45 1","pages":"174 - 196"},"PeriodicalIF":0.6,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42536197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Safety of Steel Arch Support Operation During Rock Bursts Under Explosive Atmosphere Conditions 爆炸环境下岩石爆破钢拱支护作业的安全性

IF 0.6

Studia Geotechnica et Mechanica Pub Date : 2023-03-17 DOI: 10.2478/sgem-2023-0004

A. Pytlik, W. Frąc

{"title":"Safety of Steel Arch Support Operation During Rock Bursts Under Explosive Atmosphere Conditions","authors":"A. Pytlik, W. Frąc","doi":"10.2478/sgem-2023-0004","DOIUrl":"https://doi.org/10.2478/sgem-2023-0004","url":null,"abstract":"Abstract Methane and coal dust explosions are among the most common causes of disasters in hard coal mining. Therefore, it is important for occupational safety in hard coal mines operating under methane and coal dust explosion hazards to identify possible ignition sources, whether due to natural or technical factors. One technical source of ignition can be mechanical sparks generated during operation of mechanical equipment and high surface temperatures of equipment components during operation. This paper presents the methodology and results of thermal imaging and strength testing of roadway support elements under dynamic loading. The goal of the tests was to identify the potential explosive atmosphere ignition sources during the operation of the support under the conditions of rock bursts. The scope of testing encompassed the temperature measurements by means of thermal camera of friction prop and yielding support frame sliding joint elements at yield under dynamic impact loading (simulating a burst). Significant joint element heating and mechanical sparking was observed during the testing of arching yielding support frame sliding joints and straight friction prop joints as a result of friction at yield. Some of the aspects defined in standard PN-EN ISO80079-36:2016 include the maximum temperature T max =150°C for a surface that can accumulate a layer of coal dust. Tests of the friction joints have shown that during impact loading, numerous mechanical sparks are produced at the friction joints of sections of the steel prop, with the surface temperature of the sections starting from 169.6°C and reaching up to 234.1°C. During tests it was also to determined emissivites of the tested sliding joints constructed from V29-V32 secrions depending on corrosion products which consist in range 0.842–0.873. Such a high temperature can initiate an explosive mixture consisting of methane, air and coal dust.","PeriodicalId":44626,"journal":{"name":"Studia Geotechnica et Mechanica","volume":"45 1","pages":"144 - 157"},"PeriodicalIF":0.6,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43549540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0