Soil Deformation Research Articles

Influence of soil-structure interaction modeling on the behavior of multi-story plane steel frames with shallow footing foundations

Traditionally, structural analysis is based on the hypothesis that supports are indeslocable due to simplicity. However, the conventional design in which settlements of foundation elements are disregarded can lead to physical results that are incompatible with reality. This work aims to analyze the influence of the consideration of soil-structure interaction (SSI) on the responses of steel structural elements obtained by a static second order analysis. Furthermore, it is evaluated the responses obtained by different types of procedures for the consideration of soil stiffness in the structural analysis. Solid elements considering linearly elastic material parameters and spring elements based on the Winkler theory are employed. The analyses were performed with the commercial software SAP2000. Plane steel frames models were analyzed, either considering conventional supports or taking into account the soil-structure interaction. Shallow footing foundations are considered. Three frames with the same characteristics, but with a different number of floors were analyzed, showing the influence of the height increase and the building stiffness on the SSI results. It has been shown that the consideration of the effects of soil-structure interaction on structural analysis of buildings can have a significant influence on the stress distribution, displacements and structural behavior. In addition, it is concluded that the structural capacity of steel frames can be affected by the type of support adopted and by changes on the way the model considers soil deformation.

Mathematical modeling formation of wole drainage under soil deformations

In agriculture, the processing of land plots from underground is one of the modern problems. To solve this problem, new scientific and technical approaches to agricultural technology are required. This article presents data on the formation of mole drainage during washing of saline soils. The newly created technical device has a thick-walled conical-cylindrical shape. Here it is experimentally analyzed that the soil is deformed and does not lose its stability. Experimental data were obtained by numerical element and coordinate methods. It is compared with the results of a numerical solution obtained on the basis of an exact circuit of the device. The study of nonlinear processes of compression and supercritical deformation of the soil forming the mole drainage due to soil pressure is a complex and important scientific and technical problem.The discrepancy between the results of field and computational experiments, as well as the characteristics of the accepted mathematical model and the method of their solution, associated with the rough discretization of the original problem, are characterized by external pressure forces. Therefore, experimental and theoretical studies evaluating the accuracy of methods for numerical analysis of nonlinear problems of soil deformation during the formation of mole drainage under various types of pressure and loads, as well as the study of the influence of initial deficiencies on the results of solutions, are considered relevant issues. In this article, mathematical models were created for the relationships between deformations, stresses and coordinates of the solution of the above problems, as well as their numerical solutions were considered.

Justification of the width of the tooth spacing and the distance between the rows of teeth of the ripper for the harrower

The article substantiates the degree of immersion of working bodies in the soil and soil deformation on the basis of scientific and experimental studies of the harrowing unit used. The parameters of the harrow teeth, the qualitative performance of the technological process of the accepted parameters are also theoretically justified.

Аassessing the Distribution of Statistical Heterogeneity of the soil deformation modulus based on static soil sensing

Cone penetration testing (CPT) has become one of the most commonly adopted in situ tests for site investigations, due to its reliability and repeatability of the measurements and the potential for direct use in design. CPT data we performed to a depth 5m in sandy soils within an area of 50x50m2 of 232 datasets, the significant of cone resistance force were analysis used statistical methods. The heterogeneity of soil deformation modulus was vertical and horizontally in three-dimensional plane analyzed. Data was shows vertically heterogeneity soil deformation but horizontally not heterogeneity.

Numerical Investigation on Buried Pipelines Subjected to Permanent Ground Deformations Due to Shallow Slope Failure

Permanent ground deformations (PGDs) induced by slope failures cause catastrophic damage to buried pipelines. This paper presents a 2D plane-strain numerical analysis of the behavior of a 800 mm water transport pipeline buried in the Aine-Tine slope (Mila, Algeria) subjected to shallow PGD, as it could be triggered by the recent earthquake of August 07th, 2020 (M= 4.9). The analysis is carried out through the application of an incremental displacement to simulate the soil-pipeline interaction while focusing on the effect of (1) the magnitude of the PGD and (2) the rigidity of the pipeline on the structural response of the pipeline. The elasticperfectly Mohr-Coulomb model was used to simulate the soil behavior and the elastic model was used to simulate that of the steel pipe. Pipeline deformations (i.e., translation and ovalization) and radial internal forces’ (i.e., axial forces F୅, shear forces Fୗ and bending moments M୆) results highlighted that shallow PGD can exert additional loads on pipelines that are proportional to the magnitude of the PGD. It has been found that the soil deformations as well as the internal forces induced on the pipeline ring are higher for rigid pipelines. Moreover, the results indicated that rigid pipelines are more effective than flexible ones as far as ovalization-serviceability limit state is concerned. In effect, for PGD magnitudes of 0.5, 1 and 2 m, the ovalization values of the flexible pipeline are, respectively, higher by 23%, 21% and 18% than those calculated for the rigid pipeline. Through a simplified linear numerical simulation such as that presented in this study, engineers and planners could be guided to foresee the possible causes of pipeline leaks and the mechanisms of ruptures that lead very often to severe disruption of pipelines’ normal operation. KEYWORDS: Soil-structure interaction, Slope failure, Permanent ground deformation, Pipelines, Radial internal forces, Ovalization

Моделирование динамики промышленного трактора при низкочастотном вибровозбуждении со стороны гусеничного движителя

The article is devoted to the development of a mathematical model of an industrial tractor with a semi – rigid suspension. The model is intended for the computational study of vibrations at the driver's seat caused by low – frequency impact from the caterpillar mover. A review of wel l–known mathematical models describing the dynamics of the system “soil – caterpillar mover – tractor body – cabin – vibration protection seat – driver” is made. Various methods of soil modeling and tractor caterpillars are considered. It is proposed to use the ANSYS Motion software package to simulate the subsystem "soil – caterpillar – track rollers – bogie". The model describes in detail the undercarriage system, taking into account the actual geometry of the tracks, the arrangement of the track rollers, as well as other design features. To describe the deformation of the soil in the software package, are used the relations by Becker and Wong. The article presents the results of modeling the dynamics of the tracked bogie of the industrial tractor T–130 of the Chelyabinsk Tractor Plant when moving on deformable soil. Calculations were made for three types of soil and for different locations of road wheels. The processes of vertical and angular displacements of the bogie are obtained. An analysis of the calculation results showed that the proposed model reveals the influence of soil properties and the design of the running system on the vibrations of a moving tractor. The processes obtained as a result of the simulation will be used as an input for the model describing the subsystem “tractor body – cab – vibration protection seat – driver”. The model will be used for computational studies when optimizing the vibration protection of the tractor operator. Recommendations will be developed to change the arrangement of the road wheels and the elastic–damping characteristics of the vibration protection elements to minimize the vibration impact on the tractor operator

Theoretical substantiation of low-frequency shock-contact impact as a way to increase the efficiency of ultrasonic drilling of extraterrestrial soil

A physical and mathematical model of ultrasonic destruction and deformation of solid soil has been developed, taking into account the presence of additional influences (low-frequency impact, rotational). The numerical implementation of the model is carried out in the form of a computer program for calculating the process of deformation and destruction of the soil. The presented results of calculations proved the possibility of additionally increasing the efficiency of ultrasonic drilling by more than 2.5 times due to the imposition of low-frequency shock-contact action.

A mayfly optimisation method to predict load settlement of reinforced railway tracks on soft subgrade with multi-layer geogrid

An essential consideration in constructing this retaining structure is the deterioration of geosynthetic reinforced soil (GRS) earth structures. However, artificial intelligence can solve geotechnical problems, according to the literature. This study will show that soft computing can predict geogrid-reinforced structure deformation on railway tracks. Designing and assessing a geogrid model with poor soil railroad track material is offered. An underlying soft subgrade's effective bearing capacity is increased using the geogrid. AI predicts fine-grained soil deflection based on load cycles. The geogrid is managed using the mayfly optimisation algorithm (MOA), and it discovered that MOA prediction models function adequately. The performance of the suggested prediction models of geogrid reinforced deformations is assessed regarding the settlement, bearing capacity, deformation, and pressure of weak soil in the railway track. They were built by numerical analysis in MATLAB. The suggested technique is contrasted with traditional approaches like the cuttlefish algorithm (CFA), Harris Hawk optimisation (HHO), and artificial neural networks (ANN).

UnSaLuDo: The development of an educational board game on unsaturated soil mechanics

Non-conventional tools of teaching are effective in delivering deep learning of scientific facts as well as skills associated with scientific disciplines. A well-known method to promote student engagement and learning in general is the use of games in classrooms. Games can provide a flexible option that could engage students, create active learning experiences, and enable them to experiment in safe playful environments. This paper presents UnSaLuDo, a board game developed by the GeoFUN group. The goal was to develop a tool that enables students to experience fun and integrational activities in a classroom setting while learning complex scientific targeted threshold concepts related to unsaturated soil mechanics. The topics covered by UnSaLuDo included fundamental concepts of cohesion and adhesion in liquids, surface tension, contact angle and capillary rise; water retention and water flow in unsaturated soils; volume change, deformation, and shear strength of unsaturated soils. This paper provides background information on the motivation for the development of the board game and an overview of the topics covered. The paper also presents all the components of the board game developed and suggests approaches for how it can be incorporated into geotechnics courses.

Monitoring Study of Long-Term Land Subsidence during Subway Operation in High-Density Urban Areas Based on DInSAR-GPS-GIS Technology and Numerical Simulation

During subway operation, various factors will cause long-term land subsidence, such as the vibration subsidence of foundation soil caused by train vibration load, incomplete consolidation deformation of foundation soil during tunnel construction, dense buildings and structures in the vicinity of the tunnel, and changes in water level in the stratum where the tunnel is located. The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas. The former is the gathering point of the entire urban population. There are many complex buildings around the project, busy road traffic, high pedestrian flow, and less vegetation cover. Several existing items require monitoring. However, monitoring distance is long, and providing early warning is difficult. This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation. Then, it selects multiscene image data to analyze long-term land subsidence of high-density urban areas during subway operation. Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small, with maximum subsidence of 30.64 mm, and minimum subsidence of 11.45 mm, and average subsidence ranging from 19.27 to 21.33 mm. And FLAC3D software was used to verify the monitoring situation, using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load, and the simulation results tended to be consistent with the monitoring situation.

Stability analysis of unsaturated soil slope considering softening and non-softening approach

In conventional geotechnical engineering practice, peak shear strength parameters are widely used in the design of geo-structures constructed with or within unsaturated soils. However, a reduction inshear strength from the peak to the residual value is typically observed during the shear deformation in typical fine-grained unsaturated soils. Several geo-structures in unsaturated soils undergo a large shear deformation prior to reaching the failure condition. Thus, the factor of safety of such geo-structures will gradually but significantly decrease with the development of the shear deformation. For this reason, the strain-softening behaviour of unsaturated soils should be considered for reliable design of the geo-structuresin unsaturated soils. In this study, an unsaturated clay slope under 10 years rainfall infiltration were modelled using softening and non-softening approach using commercial finite element software SIGMA/W. The responses of the studied slope to the long-term rainfall infiltration were analysed. The results of the softening and non-softening analysis were compared. This study provides valuable information with respect to the significance of the strain-softening that are useful in the rational design of slopes in unsaturated soils.

Geotechnical justification of the stadium construction on water-saturated soils under seismic loading

One of the main issues in the design of bases and foundations on water-saturated soils in conditions of possible seismic impacts is the geotechnical substantiation of the possibil-ity of construction. Among the main influencing factors, one can single out the assessment of the ability of water-saturated sandy soil to resist vibration liquefaction. The paper presents the re-sults of studying the behavior of sandy soil samples under conditions of triaxial cyclic loading, which is equivalent in strength to seismic action. The urgency of the problem lies in the study of the process of vibration liquefaction with an assessment of the deformability of water-saturated soils under dynamic influences. The tests were carried out in a pneumatic stabilometer. A special technique has been developed that provides for the imposition of dynamic stresses on the static stress state of the samples. The criteria for vibration liquefaction have been determined. A ge-otechnical substantiation of the possibility of building a stadium on water-saturated sandy soils under conditions of seismic loading has been carried out. The parameters of the earthquake, in which the soils will show liquefaction, have been established.

Stability of dam slopes taking into account anisotropy

This paper presents the results of experimental studies on the deformation and strength anisotropy of gravel-pebble soils used in soil dams. During stabilometric tests, varying shear angles were obtained for stone at different orientations of soil particles in the working chamber, whether horizontal or vertical. As the hydrostatic pressure in the working chamber increased to 0.8 MPa, a reduction of shear angles of a stone by 8-12 degrees depending on the direction of layering of soil was observed. The authors compiled a calculation program called OTKOS_Ani (Delphi), which considers the strength anisotropy of pebble soils for calculating the stability of slopes of soil dams and slopes. The slope calculations were carried out for different design and height of stone and stone-soil dams, and correction factors for taking into account the strength anisotropy in slope stability calculations, kан, were obtained depending on the type, height, and density of gravel-pebble soil stacking in the dam body. The results showed that considering the anisotropy of strength properties in the calculations of slope stability of earth dams reduces the safety factors by 3-11%. This should be taken into account when selecting the design of earth dams with prisms of gravel-pebble soils.

Динаміка гетерогенності агрофізичної якості чорнозему звичайного у межах сільськогосподарського поля

The article presents data on monitoring the physical characteristics of the soil in a field under corn (after sunflower) in a grain-row crop rotation with minimal tillage technology. Soil – Calcic Chernozem, light-medium clayey, weakly xeromorphic on loess in the Donetsk region in the Steppe climate zone of southeastern Ukraine. The research carried out in a stationary field experiment to study the effectiveness of abandoning plowing under the soil and climatic conditions of the region. During the growing season of corn for grain, the physical characteristics of the soil were monitored – bulk density, penetration resistance, and moisture content; before sowing the crop, the structural condition was determined. Measurements carried out in three locations – zones of the field, which differ on the intensity of compaction by agricultural machinery. All physical characteristics were investigated in separate layers (0–10, 10–20, and 20–30 cm) within the arable layer; reserves of productive moisture — in the entire soil profile. Meteorological data were obtained by own observations at a weather station in the nearby village of Sukha Balka. According to the results of the correlation and dispersion analysis of ANOVA, the presence and nature of the relationship between stability characteristics, rheological features and the water regime of the soil with its structural composition within the arable layer recorded before sowing revealed. Uneven distribution within the field of intensity of mechanical pressure on the soil forms differences in the structural composition and physical characteristics of the soil. For example, according to the state of moisture in a layer of 0-10 cm, the soil in different parts of the field is in a state of overwetting, overdried or optimal. The bulk density of the upper soil layer is related not only to its own structural characteristics, but also to the composition of aggregates in the layer located below. High penetration resistance, high aggregate content of 5-3 mm and low aggregate content of 2-1 mm in the upper layers can cause deep soil deformation under machine pressure. The dynamicity of the bulk density of the upper soil layer, its low content of aggregates of 5–3 mm and high content of 2–1 mm provides protection against compaction of the soil layers located below.

LSTM-based Prediction of Excavating Resistive Force Using Bucket Trajectory Shape

Unmanned construction machine has become a promising technology in the civil engineering field. The machine is still less efficient, especially in excavating soil, than the manned construction because the unmanned machine works carefully to avoid potential hazards due to unpredicted soil deformation as well as excavation force. This research aims to predict time-series resistive force of bucket during soil excavation based on the Recurrent Neural Network. First, we experimentally obtain excavating resistive force for various excavation trajectories. In the experiment, a bucket follows pre-determined trajectories with four different elliptical arcs, and the resistive force acting on the bucket is measured. The prediction model of the resistive force is then elaborated by indexing the bucket trajectories. The model validation confirms that the aspect ratio of the ellipse of the trajectories is an effective index for accurately predicting the excavating resistive force.

Pile-slab foundation’s settlement evaluation in pseudo-nonlinearity formulation

In this paper, an analytical solution to the problem of the interaction of a pile-slab foundation with a 2-layer elastic soil basement is proposed. A new method was proposed to take into account the nonlinearity of soils in an elastic formulation. This method consists in limiting the bearing capacity of the pile along the lateral surface by the strength of the adjacent soil and redistributing the applied load to the pile toe. In the article, a comparative analysis of the proposed analytical solution of the problem in the elastic formulation with numerical simulation in the elastic-plastic formulation is carried out and the scope of the proposed analytical solution, which taking into account the described mechanism of the nonlinearity of the soil, is investigated. Numerical simulation was carried out in the geotechnical software package Plaxis 2D. According to the results of analytical and numerical calculations, the graphs of the dependence of settlement on loads were constructed for various values of soil strength. The graphs showed significant differences in the rate of development of plastic zones of soil deformation obtained by analytical and numerical methods.

Modeling of segmental excavator working tool for soil compaction

The development of a methodology for physical modeling of the working process and a replaceable working tool of an excavator for soil compaction in the construction, maintenance, and repair of man-made engineering structures in confined spaces are considered in the article. This methodology is based on a rheological model of the soil compaction process containing Hooke and Newton's elements connected in parallel (the Voigt model is the method of integral analogs that have been used to obtain the main similarity criteria that adequately characterize the process of static compaction during elastoviscoplastic soil deformation). The formulas for the transition from the model parameters to the parameters of the full-scale process of soil compaction by a segmental working tool are obtained based on similarity criteria for modeling the option without changing soil properties.

Justification of parameters of working body of deep loosener

The article presents the analysis results on the study of physical-mechanical properties of soils in Uzbekistan and experimental studies on the influence of parameters and rational geometric shape of working tools on the quality of soil tillage while reducing energy costs. It has been established that soil moisture and hardness in the periods of basic and pre-sowing tillage differ significantly according to weather conditions, agrophonous background, and sowing and harvesting technology of agricultural crops. The peculiarities of different soils and the main directions of preserving and increasing their fertility are considered. The problems of optimization of physical properties and issues of the fertility state of irrigated soils are highlighted. Special attention is paid to the problems of improving soil's basic physical and mechanical properties. The use of effective technologies for improving and ameliorating irrigated lands, increasing fertility, and reducing and preventing soil salinization is proposed. For prevention of decrease and preservation of soil fertility, purposeful measures on improvement of physical properties of soils are recommended, the mechanism of which solution is the application of innovative technology of processing providing purposeful growth and development of root system, moderate moisture of soil, increased water permeability, moisture stocks, and reduction of salinization. To prevent intensive moisture evaporation after deep tillage, it is recommended to carry out agrophobic treatment by maximum leveling and creating a shallow crumbly surface layer. To substantiate the parameters of the deep loosener were based on the fact that the degree and magnitude of soil deformation depend on both the shape and parameters of interacting working bodies and on the physical and mechanical properties of the cultivated medium.

Influence of Stump-Root System of Trees on Rut Formation During Forwarder Operation on Peat Soils

To explain the soil deformation processes under the influence of logging machines, average values of various indicators are often used. One of these indicators is the rut depth formed during tractor passages. The average values do not fully describe the consequences of passages on the skidding trails, for example, the rut depth varies along the track. This variability includes both random and regular components. The stump-root systems of trees located on the skidding trail and along its border act as a factor that introduces a pattern. To determine the degree of influence of stumps on 8 sections of skidding trails with the length of 25 and 50 m, located on peat soils (the average mass fraction of water is 82.3%), the rut depth was measured at intervals of 0.5 m and the locations of stumps were noted. The resulting arrays of vertical marks represent the microprofiles of the experimental sections. Measurements were taken after 2 harvester passages and 2 forwarder passages. The stumps were divided into two groups: located inside the tractor track and outside it. Statistical processing of the data showed a wide spread of the rut dimensions in each array. Average values at the sections (standard deviations) in cm were: 21.6(17.7); 30.6(21.6); 37.7(22.7); 46(20.3); 36.4(15.0); 36(15.4); 30.6(21.0); 34(21.0). The autocorrelation functions, constructed for the series of values, showed surges with moderate correlation coefficients on the lags where stumps were noted. An increase in stumps per a length unit of the skidding trail shows an increase in the number of such surges. A decrease in the rut dimensions, in relation to the places where the influence of the roots was absent, averaged: in points 0.5 m away from the stump – 44% (22.6); 1 m away – 32% (20.4); 1.5 m away – 22% (14.2). The spatial influence factor of the roots explains 21% of the variability of the rut dimensions along the skidding trail. The factor of the stump location relative to the track is 19%. The combined influence of these factors is 25%. Further identification of regularities in the rut formation processes is associated both with the continuation of studies of the root system influence, but with the inclusion of factors of the stump size and variety, and with the study of the variability of the soil physical properties along the skidding trails, analysing how this is found in the microprofile structure.

Retracted: Three‐Dimensional Numerical Simulation of Soil Deformation during Shield Tunnel Construction

Retracted: Three‐Dimensional Numerical Simulation of Soil Deformation during Shield Tunnel Construction