CHANGE IN STRENGTH PARAMETERS OF DISPERSED SOILS AFTER HIGH-FREQUENCY VIBRATION

2021 ◽  
Vol 12 (1) ◽  
pp. 46-56
Author(s):  
V. M Polunin ◽  
A. P Cheremhina
Keyword(s):  
High Frequency ◽  
Field Measurements ◽  
Field Studies ◽  
Clay Soils ◽  
Laboratory Studies ◽  
Strength Parameters ◽  
High Frequency Vibration ◽  
Soil Foundation ◽  
Comparison Of The Results ◽  
Water Saturated

The use of the technology of high-frequency sheet piles driving or extraction in conditions of weak, structurally unstable soils inevitably leads to a change in the structure of the soil. This is especially true for buildings which fall into the zone of influence. Often, foundation for historical buildings is water-saturated sands, spread by fluid and fluid-plastic clay soils. In the process of external dynamic action, the soil foundation is been destructing, so their strength and deformation parameters are reduced. In this case, the result of vibration effects on a dispersed water-saturated sample can be both compaction for sandy soil and decompaction of clay soils. These changes lead to additional deformations of buildings and structures of the surrounding area. Therefore, the issue of assessing the limits of applicability of vibration technology in certain conditions is relevant. The object of the study is the changes in the properties of clay soils of various consistencies after exposure to vibration. The results of laboratory studies to determine the strength parameters of dispersed soils after high-frequency vibration are presented. The results of field measurements by CPT "before", "after" vibration immersion and vibration extraction of sheet piles are considered. Comparison of the results of field and laboratory studies is carried out to identify patterns of change in the strength characteristics of weak soils under the influence of vibration loads. A tendency towards a decrease in the strength parameters of dispersed soils is shown. Currently, due to the insufficient number of laboratory and field studies to study the effect of high-frequency vibration on the change in the strength parameters of weak water-saturated clay soils, it is not possible to identify a clear dependence of the change in parameters on the time and frequency of vibration.

Comparison Of Field And Laboratory Studies Results Of The Clay Soils Deformability Characteristics

2019 ◽  
pp. 40-45
Keyword(s):  
Low Cost ◽  
Field Studies ◽  
Field Conditions ◽  
Clay Soils ◽  
Saturated Soils ◽  
Natural Occurrence ◽  
Laboratory Studies ◽  
Load Tests ◽  
Definition Of ◽  
Water Saturated

Determination of the deformability characteristics of weak water-saturated soils is a complex process. Firstly, it is difficult to preserve the natural structure of the soil sample taken for the study in the laboratory. Secondly, according to the latest studies, in natural occurrence there is a constant pore pressure, which must be taken into account when determining the characteristics of deformability and strength of clay soils. During many years it was established that the compressibility characteristic of soils obtained under laboratory conditions differs sharply from the result of characterization in field conditions. It is proposed to use the characteristics of compressibility and strength of soils obtained in the course of low-cost laboratory studies, compared with the definition of these characteristics in expensive field conditions. The results of the comparison of numerous laboratory and field studies of the properties of weak water-saturated soils of the base of various regions of Russia are presented. On the basis of the data obtained, when studying the characteristics of deformability of weak water-saturated clay soils, it is recommended to use only laboratory methods and not to conduct additional field plate load tests, except in the case of construction of unique structures,

scholarly journals ESTIMATION OF DYNAMIC EFFECTS FROM VIBRATION DIPPING OF SHEET PILES ON ENVIRONMENTAL BUILDINGS IN CONDITIONS OF WEAK WATER-SATURATED SOILS

2020 ◽  
Vol 11 (3) ◽  
pp. 102-116
Author(s):  
R. A Mangushev ◽  
A. V Gurskiy ◽  
V. M Polunin
Keyword(s):  
High Frequency ◽  
Soil Mass ◽  
Vibration Velocity ◽  
Sheet Pile ◽  
Significant Excess ◽  
Vibration Acceleration ◽  
Dynamic Impact ◽  
High Frequency Vibration ◽  
Soil Foundation ◽  
Water Saturated

In weak, structurally unstable soils, the use of the technology of high-frequency vibration immersion of sheet piles, in some cases, is obviously dangerous, and the issue of assessing the limits of applicability of this technology in certain conditions is relevant. The assessment of the dynamic impact on the soil foundation can be made by the level of vibrations. Regulatory documents impose requirements on the level of vibrations of the surrounding soil mass and buildings, however, it is not entirely correct to assess the influence of the technology of high-frequency vibration driving of sheet piles only by the values of vibration acceleration and vibration velocity. The object of the study is the values of deformations of foundations reinforced with piles. At the experimental construction site, we were carried out for the level of vibrations of foundations reinforced with piles 18 m length, from high-frequency vibration immersion of a pipe sheet pile with a diameter of 1200 mm and a length of 18 m. In the process of driving the sheet piles, we were making constant geodesic control over the deformations of adjoining buildings was carried out. The main results are: the example given in the article shows that when the foundations are strengthened, the deformations of the foundation (settlement) remain within the permissible values, despite the significant excess of the permissible level of vibrations of the building foundations. The proposed methodology for the numerical prediction of base deformations from vibration immersion of sheet piles gives satisfactory convergence with the results of field observations and makes it possible to assess qualitatively and quantitatively the settlements of buildings in the surrounding development from vibration immersion / extraction of sheet piles at the preliminary stages of construction.

scholarly journals Soil bases modified with lime waste and polycarboxylates

2021 ◽  
Vol 2124 (1) ◽  
pp. 012023
Author(s):  
L V Zakrevskaya ◽  
K A Nikolaeva ◽  
A I Gandelsman ◽  
P A Orekhov
Keyword(s):  
Physical And Mechanical Properties ◽  
Road Construction ◽  
Clay Soils ◽  
Infrastructure Development ◽  
Laboratory Studies ◽  
The Road ◽  
Saturated Clay ◽  
Water Saturated ◽  
The Cost ◽  
Local Materials

Abstract Increasing the volume of road construction is one of the priority areas of infrastructure development in any country. When building roads, it is preferable to use local materials to reduce the cost of their transportation, therefore, it is advisable to build the roadbed on local soils. It is worth noting that clay water-saturated soils are the most common, which complicates the construction of the road due to some features of this type of soil. The object of the study is a water-saturated clay with the following characteristics: natural humidity from 25.3 % to 28.1% by weight, optimal humidity from 11.8 % to 16.7% by weight, the number of plasticity from 0.118 to 0.153. Clay soils have a number of features: waterlogged soils are difficult to compact and develop, it is quite problematic to dry them, and thixotropy is also characteristic of clay soils. In this regard, it is most advisable to use the method of complex mineral binders to optimize their physical and mechanical properties. In the course of laboratory studies, compositions of soil compositions with the addition of lime waste and superplasticizer P-17 were developed. The dependence of the strength on the consumption of mineral binders and surfactants is established: the maximum compressive strength of the soil being fixed is achieved at a lime content of 25 wt.% and at a P-17 content in the range of 0.10-0.5 wt.%.

Tool wear analysis in high-frequency vibration-assisted drilling of additive manufactured Ti6Al4V alloy

Wear ◽  
2021 ◽  
pp. 203814
Author(s):  
Marco Sorgato ◽  
Rachele Bertolini ◽  
Andrea Ghiotti ◽  
Stefania Bruschi
Keyword(s):  
Tool Wear ◽  
High Frequency ◽  
Ti6al4v Alloy ◽  
High Frequency Vibration ◽  
Wear Analysis

Foliar Penetration and Phytotoxicity of Paraquat as Influenced by Peanut Cultivar1

1991 ◽  
Vol 18 (2) ◽  
pp. 67-71 ◽  
Author(s):  
G. Wehtje ◽  
J. W. Wilcut ◽  
J. A. McGuire ◽  
T. V. Hicks
Keyword(s):  
Arachis Hypogaea ◽  
Untreated Control ◽  
Field Studies ◽  
Yield Potential ◽  
Laboratory Studies ◽  
Foliar Absorption ◽  
Arachis Hypogaea L ◽  
Herbicide Treatments ◽  
Peanut Cultivars

Abstract Field studies were conducted over a three year period to examine the sensitivity of four peanut (Arachis hypogaea L.) cultivars (Florunner, Sunrunner, Southern runner, and NC 7) to foliar applications of paraquat (1, 1′-dimethyl-4, 4′-bipyridinium ion). Treatments included an untreated control and four herbicide treatments: paraquat applied alone at 0.14 and 0.28 kg/ha, or tank mixed with alachlor [2-chloro-N-(2, 6-diethylphenyl)-N-(methoxymethyl)acetamide] at 4.40 kg/ha. Weeds were hand-removed so that only herbicidal treatments were variables. Paraquat phytotoxicity did not differ between cultivars. No cultivar evaluated was abnormally sensitive nor tolerant to any paraquat-containing treatment. Laboratory studies utilizing radio labelled paraquat revealed that foliar absorption and translocation of paraquat did not vary between peanut cultivars. Yield differences were attributed to differences in yield potential between cultivars.

scholarly journals Microscale Capillary Wave Turbulence Excited by High Frequency Vibration

Langmuir ◽  
2013 ◽  
Vol 29 (11) ◽  
pp. 3835-3845 ◽  
Author(s):  
Jeremy Blamey ◽  
Leslie Y. Yeo ◽  
James R. Friend
Keyword(s):  
High Frequency ◽  
Capillary Wave ◽  
Wave Turbulence ◽  
High Frequency Vibration

Seasonal Changes in the Water Relations of Eucalyptus behriana F. Muell. And E. microcarpa (Maiden) Maiden in the Field

1984 ◽  
Vol 32 (5) ◽  
pp. 495 ◽  
Author(s):  
BA Myers ◽  
TF Neales
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Rainfall Intensity ◽  
Field Measurements ◽  
Canopy Conductance ◽  
Laboratory Studies ◽  
Short Term ◽  
The Mean ◽  
Type Response ◽  
Vapour Pressure Difference

Field observations of some parameters of the water relations of the two eucalypt species E. behriana and E. microcarpa in dry sclerophyll, mallee and woodland vegetation were made at three sites from 1980 to 1983. The mean ( n = 519) water potential measured at dawn (Ψdawn) was -3.07± 0.01 MPa and fluctuated seasonally with rainfall intensity over the range -2.0 ± 0, 1 to -4.4 ± 0.1 MPa ( n = 30). Both species behaved similarly and some osmotic adjustment took place. Mean leaf conductance (gs) varied between 0.151 ± 0.006 and 0.003 ± 0.001 mol m-2 s-1 . Maximum daily values of gs were linearly related to Ψdawn as it fluctuated seasonally. The slope of this linear regression was not significantly different from that relating these values of gs and Ψ, when both were measured concurrently. There were thus no indications of a distinction between the responses of gs to long- and short-term fluctuations of Ψ or of a threshold-type response of gs to Ψ. Field measurements indicated that gs was decreased at high values of vapour pressure difference (Δe). In laboratory studies with seedlings of the two species gs decreased from 0.5 to 0.1 mol m-2 s-I as Δe increased from 0.5 to 3.0 kPa. Leaf and canopy conductance were the predominant plant determinants of transpiration rate (Er) in this type of vegetation which has the capacity to restrict Et via the effect of water potential (Ψ) on gs and also by the response of gs to Δe. Some of the water relations parameters of E. behriana indicated that this species was better able to withstand drought than was E microcarpa.

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