Improvement of building properties of water-saturated loess and clay soils with alkalizing

Keyword(s):  
2018 ◽  
Vol 55 (5) ◽  
pp. 333-339 ◽  
Author(s):  
M. Yu. Abelev ◽  
I. V. Averin ◽  
D. Yu. Chunyuk ◽  
O. V. Kopteva

2019 ◽  
Vol 7 (4) ◽  
pp. 32-35
Author(s):  
Vyacheslav Glukhov ◽  
Ol'ga Hryanina ◽  
Svetlana Glukhova ◽  
Anastasia Pugina

It is known that the stress values and the distribution of the latter in depth depend to a large extent on the size of the Foundation sole and especially the width. In this article, in order to select the optimal width of the Foundation sole and the thickness of the sand cushion, the influence of the sole width on the distribution of vertical stresses in the ground base is studied on the example of foundations for metal pipes. The presence of weak water-saturated clay soils within the construction site was taken into account. Variants of the device from traditional prismatic piles and foundations of small laying on a sandy pillow are offered. a technical and economic comparison of options was carried out. The advantages and disadvantages of each option are analyzed. Using the methodology of verification calculations in the design of sandbags, the optimization of the accepted version of the foundations was made.


2021 ◽  
Vol 12 (1) ◽  
pp. 46-56
Author(s):  
V. M Polunin ◽  
A. P Cheremhina

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.


2018 ◽  
Vol 16 (1) ◽  
pp. 76
Author(s):  
A A Kislyakov ◽  
M A Kislyakov ◽  
N K Simakov

В статье рассматриваются вопросы изучения процессов консолидации водонасыщенных пылевато-глинистых грунтов. Перед исследователями ставилась задача оценки эффективности работы ленточных дрен в водонасыщенных пылевато-глинистых грунтах и определения оптимального расстояния между дренами. Методика проведения полевого эксперимента основывалась на положении о необходимости максимально возможного сохранения природной структуры грунта при установке в нем аппаратуры для исследований. Принят бесконтактный способ определения послойных деформаций грунта с помощью глубинных кольцевых марок и методы определения напряжений мессдозами и датчиками порового давления, которые устанавливались в пробуренные в массиве грунта скважины. Оборудование контрольно-измерительной аппаратурой полигонов с разным шагом дрен, а затем проведение наблюдений на них в сочетании с наблюдениями на полигоне без дрен позволяет оценить эффективность работы ленточных дрен в данных грунтах и определить оптимальное расстояние между дренами.


2017 ◽  
pp. 192-201
Author(s):  
G.P. Belov ◽  
E.E. Gallyamov ◽  
A.F. Khaziev ◽  
N.V. Shutov

2021 ◽  
Vol 2124 (1) ◽  
pp. 012023
Author(s):  
L V Zakrevskaya ◽  
K A Nikolaeva ◽  
A I Gandelsman ◽  
P A Orekhov

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.%.


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,


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