Изменения характеристик грунтов уплотненных длительно действующей нагрузкой

Abstract

RU: Охарактеризованы изменения характеристик грунтов в процессе уплотнения их длительно действующей нагрузкой.

EN: The soil bases under the influence of the load duration, natural and anthropogenic factors change the physical and mechanical characteristics. The study of the soil characteristics before the construction of buildings and after its long exploitation in order to determine the possibility of increasing loads on the basis of reconstructed buildings are ofpractical interest. Based on the results of such studies the methods for predicting changes in the characteristics of soils under the influence of the load duration, taking into account natural and anthropogenic factorscan be developed.

Numerous studies show that the greatest impact on the amount of additional sediment at the superstructure has a change in the mechanical characteristics associated with soil compaction under the weight of the building. With long–term effects of pressures on soils in the process of operation of buildings base foundations undergo the following changes:

– Void ratio decreases, resulting in strengthening soil bases and the deformation modulus of soilincreases;

– The humidity within the building areaincreases, which leads to decrease of bearing capacity of soil.

From the results of research, P. Konovalov, E. Sorochan, L. Morareskula it has been known that long–term operation of buildings leads to the development of a number of both positive and negative processes in the foundation soil. Compaction of foundation soils at the top of the compressible strata under the foundationrefers to positivefactors resulting in a decrease in porosity, increasing their strength and deformation properties, increasing the bearing capacity of soils. Also,negative processes which lead to weaken the properties of soils are fixed the base of long time operated buildings. For example, the increase humidity of soils in the upper part of the base, caused by seasonal freezing and thawing of soil, leaks of water from technogenic communications which are located in a spot of building construction. Theincrease of the level of groundwater, or the increase in humidity can cause deterioration of the strength and deformation characteristics of the foundation soils.