The Daxinganling Island Taliks Sheet Permafrost Feature

2013 ◽  
Vol 368-370 ◽  
pp. 1816-1820
Author(s):  
Lin Ding ◽  
Yan Jie Liu ◽  
Yi Mei Min
Keyword(s):  
Field Investigation ◽  
Liquid Limit ◽  
Frozen Soil ◽  
Frost Heave ◽  
Theoretic Analysis ◽  
Plastic Limit ◽  
Geological Conditions ◽  
Natural Water Content ◽  
Thaw Depth ◽  
Limit Index

In order to study the features of permafrost in Daxinganling, based on t he methods of field investigation and borehole drilling, as w ell as theoretic analysis and the effects of frozen soil geological conditions, topography features, frozen soil type and permafrost classification the freeze-thaw depth(m),main physical indicators of the Frost soil, natural water content, plastic limit Liquid limit index were analysis .the thaw settlement and frost heave were studied in this paper.

Analysis of Obstacle of Development and Application that Coal Gangue Used in China Road Engineering

2014 ◽  
Vol 900 ◽  
pp. 510-513 ◽  
Author(s):  
Qing Qing Ma ◽  
Hua Liu
Keyword(s):  
Principal Component ◽  
Liquid Limit ◽  
Coal Gangue ◽  
Plastic Limit ◽  
Engineering Material ◽  
Road Engineering ◽  
Slake Durability Index ◽  
Durability Index ◽  
Limit Index ◽  
Major Factors

Coal gangue as road engineering material can sovle the problems of energy saving and environmental protection.Experimental datas of grain size distribution,crushing value,slake durability index,expansivity,liquid limit index,plastic limit index and water absorption showed that its own characteristics are in line with the requirements of road engineering materials. There are successful cases of application of coal gangue in road constructions both here and abroad. Principal component analysis is used to identify four major factors of coal gangue applications in road construction.Put forward 5 urgent problems to be solved and give a few corresponding suggestions.

scholarly journals Correlations for undrained shear strength of Finnish soft clays

2016 ◽  
Vol 53 (10) ◽  
pp. 1628-1645 ◽  
Author(s):  
Marco D’Ignazio ◽  
Kok-Kwang Phoon ◽  
Siew Ann Tan ◽  
Tim Tapani Länsivaara
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Liquid Limit ◽  
Regression Analyses ◽  
Plastic Limit ◽  
Soft Clays ◽  
Natural Water Content ◽  
Vertical Effective Stress ◽  
First Time ◽  
Undrained Shear

The study focuses on the derivation of transformation models for undrained shear strength (su) of Finnish soft sensitive clays. Specific correlation equations for su of Finnish clays are presented in this work for the first time. Field and laboratory measurements from 24 test sites in Finland are exploited for this purpose and a multivariate database is constructed. The multivariate data consist of su from the field vane test, preconsolidation stress, vertical effective stress, liquid limit, plastic limit, natural water content, and sensitivity. The main objective is to evaluate the interdependence of su, consolidation stresses, and index parameters and provide a consistent framework for practical use. The new correlations are established through regression analyses. The constructed framework is further validated by another independent multivariate database of clays from Sweden and Norway as well as by empirical equations for Swedish and Norwegian clays. Existing correlations are evaluated for Finnish and Scandinavian clays. Finally, bias and uncertainties of the new correlations are presented.

Stress Analysis of Pipeline Subjected to Differential Frost Heave

2013 ◽  
Author(s):  
Yan Di ◽  
Jian Shuai ◽  
Lingzhen Kong ◽  
Xiayi Zhou
Keyword(s):  
Strain Analysis ◽  
Element Model ◽  
Frozen Soil ◽  
Computational Method ◽  
Frost Heave ◽  
Safe Operation ◽  
Stress Strain ◽  
Segregation Potential ◽  
Differential Frost Heave ◽  
Design Construction

Frost heave must be considered in cases where pipelines are laid in permafrost in order to protect the pipelines from overstress and to maintain the safe operation. In this paper, a finite element model for stress/strain analysis in a pipeline subjected to differential frost heave was presented, in which the amount of frost heave is calculated using a segregation potential model and considering creep effects of the frozen soil. In addition, a computational method for the temperature field around a pipeline was proposed so that the frozen depth and temperature variation gradient could be obtained. Using the procedure proposed in this paper, stress/strain can be calculated according to the temperature on the surface of soil and in a pipeline. The result shows the characteristics of deformation and loading of a pipeline subjected to differential frost heave. In general, the methods and results in this paper can provide a reference for the design, construction and operation of pipelines in permafrost areas.

Microstructure-Based Random Finite Element Method Simulation of Frost Heave: Theory and Implementation

2018 ◽  
Vol 2672 (52) ◽  
pp. 347-357 ◽  
Author(s):  
Shaoyang Dong ◽  
Xiong (Bill) Yu
Keyword(s):  
Finite Element ◽  
Ground Surface ◽  
Finite Element Method Simulation ◽  
Element Model ◽  
Frozen Soil ◽  
Traffic Load ◽  
Frost Heave ◽  
Holistic Model ◽  
Water Pipes ◽  
Random Finite Element

Frost heave can cause serious damage to civil infrastructure. For example, interactions of soil and water pipes under frozen conditions have been found to significantly accelerate pipe fracture. Frost heave may cause the retaining walls along highways to crack and even fail in cold climates. This paper describes a holistic model to simulate the temperature, stress, and deformation in frozen soil and implement a model to simulate frost heave and stress on water pipelines. The frozen soil behaviors are based on a microstructure-based random finite element model, which holistically describes the mechanical behaviors of soils subjected to freezing conditions. The new model is able to simulate bulk behaviors by considering the microstructure of soils. The soil is phase coded and therefore the simulation model only needs the corresponding parameters of individual phases. This significantly simplifies obtaining the necessary parameters for the model. The capability of the model in simulating the temperature distribution and volume change are first validated with laboratory scale experiments. Coupled thermal-mechanical processes are introduced to describe the soil responses subjected to sub-zero temperature on the ground surface. This subsequently changes the interaction modes between ground and water pipes and leads to increase of stresses on the water pipes. The effects of cracks along a water pipe further cause stress concentration, which jeopardizes the pipe’s performance and leads to failure. The combined effects of freezing ground and traffic load are further evaluated with the model.

scholarly journals Finite Element Analysis of Artificially Frozen C-Phi soil

2019 ◽  
Vol 8 (4) ◽  
pp. 12722-12728
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Frozen Soil ◽  
Experimental Results ◽  
Soil Freezing ◽  
Strength Parameter ◽  
Frozen Ground ◽  
Element Analysis ◽  
Test Setup ◽  
Geological Conditions

Artificial Ground Freezing techniques eliminate the need for structural supports during the course of an excavation, as frozen ground is solid and waterproof. At present, it is adopted as an effective way to deal with various construction ground control challenges such as the mitigation of seepage infiltration into tunnels and shaft excavations; or ground strengthening for excavation. In-depth knowledge of the frozen soil characteristics through experiments and the development of suitable constitutive models that suit the geological conditions of our country are necessary to predict the strength and behavior of the frozen soils. Numerical analysis of frozen soil can be used for mass works like tunneling which cannot be experimentally verified. This paper presents a validation of experimental results obtained from laboratory setup and soil freezing system for C-Phi soil. The main aim is to compare numerical and experimental results and hence obtaining the shear strength parameter of the soil, similar to the conventional triaxial test setup. To perform numerical analysis Finite element tool ANSYS 19 is used. Soil model is made in ANSYS 19 and required loads are inputted to performed the analysis similar to the experimental method. The result obtained from experimental test setup and numerical analysis was verified and compared and it was found that values of numerical results lies closer to experimental results

scholarly journals Prediction of Shear Strength of Soil Using Direct Shear Test and Support Vector Machine Model

2020 ◽  
Vol 14 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Hai-Bang Ly ◽  
Binh Thai Pham
Keyword(s):  
Support Vector Machine ◽  
Shear Strength ◽  
Moisture Content ◽  
Mean Squared Error ◽  
Learning Algorithm ◽  
Liquid Limit ◽  
Support Vector ◽  
Plastic Limit ◽  
Svm Model ◽  
Soil Shear Strength

Background: Shear strength of soil, the magnitude of shear stress that a soil can maintain, is an important factor in geotechnical engineering. Objective: The main objective of this study is dedicated to the development of a machine learning algorithm, namely Support Vector Machine (SVM) to predict the shear strength of soil based on 6 input variables such as clay content, moisture content, specific gravity, void ratio, liquid limit and plastic limit. Methods: An important number of experimental measurements, including more than 500 samples was gathered from the Long Phu 1 power plant project’s technical reports. The accuracy of the proposed SVM was evaluated using statistical indicators such as the coefficient of correlation (R), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) over a number of 200 simulations taking into account the random sampling effect. Finally, the most accurate SVM model was used to interpret the prediction results due to Partial Dependence Plots (PDP). Results: Validation results showed that SVM model performed well for prediction of soil shear strength (R = 0.9 to 0.95), and the moisture content, liquid limit and plastic limit were found as the three most affecting features to the prediction of soil shear strength. Conclusion: This study might help in quick and accurate prediction of soil shear strength for practical purposes in civil engineering.

Mechanics of Buried Chilled Gas Pipelines

1996 ◽  
Author(s):  
A. P. S. Selvadurai ◽  
J. Hu
Keyword(s):  
Three Dimensional ◽  
Frozen Soil ◽  
Frost Heave ◽  
Elastic Behaviour ◽  
Full Scale Test ◽  
Flexural Behaviour ◽  
Moisture Migration ◽  
Factors Influencing ◽  
Scale Test ◽  
Interaction Test

This paper examines the factors influencing the modelling of soil-pipeline interaction for a pipeline which is used to transport chilled gas. The soil-pipeline interaction is induced by the generation of discontinuous frost heave at a boundary between soils with differing frost susceptibility. The three-dimensional modelling takes into consideration the time-dependent evolution of frost heave due to moisture migration, the creep and elastic behaviour of the frozen soil and flexural behaviour of the embedded pipeline. The results of the computational model are compared with experimental results obtained from the frost heave induced soil-pipeline interaction test performed at the full scale test facilities in Caen, France.

scholarly journals Prediction of Consolidation Characteristics from Index Properties

2018 ◽  
Vol 65 ◽  
pp. 06004
Author(s):  
Kok Shien Ng ◽  
Yee Ming Chew ◽  
Nur Izzati Ahmad Lazim
Keyword(s):  
Regression Analysis ◽  
Cohesive Soil ◽  
Liquid Limit ◽  
Index Properties ◽  
Compression Index ◽  
Plastic Limit ◽  
Considerable Time ◽  
Coefficient Of Consolidation ◽  
Good Relationship ◽  
Two Parameters

Compression index and coefficient of consolidation are two most important parameters in obtaining the consolidation characteristics of cohesive soil. Considerable time and effort are required to obtain these parameters from the oedometer test. Therefore, this study aims to correlate these two parameters with the index properties. Five remoulded samples are tested for their physical properties as well as their consolidation characteristics. The results show good relationship was obtained for the liquid limit and the compression index while the coefficient of consolidation is best correlated with the plastic limit. Multiple regression analysis was performed to improve the prediction. Liquid limit is best coupled with specific gravity to estimate the compression index while plastic limit and plastic index can be used to best predict the coefficient of consolidation.

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