Disintegration characteristics of collapsible loess after vibration compaction

Study of rheological properties of concrete mixtures based on modified cement systems in order to determine process parameters. Methodology. To study structural-mechanical properties of modified concrete mixtures of different consistency at their horizontal vibrating displacement an oscillatory viscometer was designed. Results. The optimization of the process of vibration displacement of concrete mixtures with the specification of parameters of vibration impacts taking into account structural-mechanical properties of the mixture is performed. It has been established that the viscosity of the modified cement system of the concrete mixture is a variable quantity, which depends on the parameters of the vibration impacts. Scientific novelty. The mechanism of interaction of the modified concrete mixture with the form and the table vibrator during its vibration compaction is determined. On the basis of this, a model of concrete laying process control is proposed, that allows to predict the ability to form a dense concrete structure. Practical significance. Disclosed physical nature of the process of vibrating displacement of modified concrete mixtures using the principles of physical-chemical mechanics of concrete allows reasonably choose the best options for vibration impacts.

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Study on negative friction of pile foundation in single homogeneous soil layer in collapsible loess area of Northwest China

Arabian Journal of Geosciences ◽

10.1007/s12517-021-07508-2 ◽

2021 ◽

Vol 14 (12) ◽

Author(s):

Shuaihua Ye ◽

Zhuangfu Zhao ◽

Yanpeng Zhu

Keyword(s):

Pile Foundation ◽

Soil Layer ◽

Northwest China ◽

Loess Area ◽

Collapsible Loess ◽

Homogeneous Soil ◽

Negative Friction

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Liquefaction-induced flow slide in the collapsible loess deposit in Tajik

Earthquake Geotechnical Case Histories for Performance-Based Design ◽

10.1201/noe0415804844.ch26 ◽

2009 ◽

pp. 431-448 ◽

Cited By ~ 1

Author(s):

K Ishihara

Keyword(s):

Loess Deposit ◽

Flow Slide ◽

Collapsible Loess ◽

Induced Flow

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Experimental study on high energy level dynamic compaction of collapsible loess with large thickness and low water content

Architectural, Energy and Information Engineering ◽

10.1201/b19197-157 ◽

2015 ◽

pp. 717-720

Author(s):

C Wang ◽

H Geng ◽

E Song

Keyword(s):

Experimental Study ◽

Energy Level ◽

Water Content ◽

High Energy ◽

Dynamic Compaction ◽

High Energy Level ◽

Large Thickness ◽

Collapsible Loess

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Numerical simulation of the behavior of collapsible loess

Numerical Methods in Geotechnical Engineering IX ◽

10.1201/9781351003629-7 ◽

2018 ◽

pp. 53-57

Author(s):

R. Schiava

Keyword(s):

Numerical Simulation ◽

Collapsible Loess

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Study on the Hydro-Thermal-Mechanical Characteristics of the Lime-Soil Compaction Pile in the Forming Process

Advances in Materials Science and Engineering ◽

10.1155/2021/7701423 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Fengchuan Zhang ◽

Jianhua Dong ◽

Xiaoyu Yang ◽

Bo Lian ◽

Xuelang Wang

Keyword(s):

Soil Compaction ◽

Pressure Change ◽

Soil Pressure ◽

Expansion Process ◽

Forming Process ◽

Collapsible Loess ◽

Influence Of Water ◽

Force Characteristics ◽

Temperature Water ◽

Pore Expansion

To study the effect of the lime-soil compaction pile on the collapsible loess foundation and the influence of water-heat-force characteristics on the soil during compaction, the field test of lime-soil compaction pile treatment of collapsible loess foundation is carried out. This paper monitors the process of soil temperature, water, and soil pressure change in the process of pile forming. According to the macroprocess and micromechanism of lime-soil compaction pile treatment of collapsible loess foundation, the qualitative law of water-heat-force change in the process of pile forming is obtained. Meanwhile, the influence of soil damage is introduced in the process of compaction expansion. The model of pore expansion under linear damage conditions in the plastic zone is established. The formula of radial stress distribution under damage conditions is given. The influence of different damage factors on the expansion process is analyzed.

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Investigation on cement-improved phyllite based on the vertical vibration compaction method

PLoS ONE ◽

10.1371/journal.pone.0247599 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247599

Author(s):

Yingjun Jiang ◽

Jiangtao Fan ◽

Yong Yi ◽

Tian Tian ◽

Kejia Yuan ◽

...

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Unconfined Compressive Strength ◽

Static Pressure ◽

Cement Content ◽

Vertical Vibration ◽

Pressure Method ◽

Vibration Compaction ◽

Modulus Of Resilience ◽

Compaction Method

The vertical vibration compaction method (VVCM), heavy compaction method and static pressure method were used to form phyllite specimens with different degrees of weathering. The influence of cement content, compactness, and compaction method on the mechanical properties of phyllite was studied. The mechanical properties of phyllite was evaluated in terms of unconfined compressive strength (Rc) and modulus of resilience (Ec). Further, test roads were paved along an expressway in China to demonstrate the feasibility of the highly weathered phyllite improvement technology. Results show that unweathered phyllite can be used as subgrade filler. In spite of increasing compactness, phyllite with a higher degree of weathering cannot meet the requirements for subgrade filler. With increasing cement content, Rc and Ec of the improved phyllite increases linearly. Rc and Ec increase by at least 15% and 17%, respectively, for every 1% increase in cement content and by at least 10% and 6%, respectively, for every 1% increase in compactness. The higher the degree of weathering of phyllite, the greater the degree of improvement of its mechanical properties.

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Collapse Potential of Loess under Unloading Effect

Advances in Civil Engineering ◽

10.1155/2021/6617228 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Xin Jin ◽

Tie-Hang Wang ◽

Zai-Kun Zhao ◽

Liang Zhang ◽

Yan-Zhou Hao

Keyword(s):

Low Cost ◽

Initial Pressure ◽

Threshold Value ◽

Building Construction ◽

Stress Variation ◽

Collapse Potential ◽

Evaluation Scheme ◽

Practical Project ◽

Collapsible Loess ◽

Collapse Process

Collapsible loess is generally characterized by a sudden and substantial decrease in volume that occurs when is applied under constant stress. To evaluate the loess collapse potential, the self-weight collapse and collapse coefficients have been defined by the code for building construction in collapsible loess regions. However, the method in the code does not account for the vertical stress variation. The loess collapse process commonly occurs with stress variation in practice. This paper documents a low-cost, quantitative evaluation scheme using regression analysis to evaluate the loess collapse potential by varying the unloading levels. The results show that the factors that prominently account for loess collapse deformation are the initial pressure, unloading ratio, and collapse completed-ratio. At a constant collapse-completed ratio, the remnant collapse coefficient significantly decreases with the decreasing unloading ratio; at a constant unloading ratio, the remnant collapse coefficient increases with a decreasing collapse-completed ratio. Decreasing unloading and collapse-completed ratios decreased the loess collapse potential with an initial pressure that exceeds the threshold value. Finally, an unloading collapse deformation calculation of loess was prepared to analyze practical project problems of loess based on the unloading collapse test.

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