Experience in the application of surface foundations for a frame building in the vicinity of St. Petersburg

The article presents the experience of constructing buildings on surface foundations in winter season. Within the frames of the investigation, there were evaluated temperatures in the base composed of heaving soils, as well as foundation displacements during the winter period. There have been were performed calculations of temperature fields and soil heaving deformation using the Termoground program. It is shown that despite the relatively big depth of the base soil freezing, the maximum displacements of the foundations did not exceed 7 mm, which is quite acceptable for a frame building.

Determination of cracking causes in building structural elements

The article deals with the problems of buildings built many years ago, in which current and major repairs were not carried out in an appropriate manner. At the same time, buildings experience various deformations, such as yield, heel, subsidence, deflections, bends, twists, distortions, horizontal displacements. The survey of residential buildings built in the 80s is described and the analysis of the results of the survey of one of these buildings is carried out. The theoretical problem of the distribution of moisture in depth and various degrees of soil moisture has been solved. The reasons for the appearance of cracks in structures and cracks between individual building elements are also determined. The survey of a 9-storey brick residential building, built in the late 80s, which is in the period of normal operation, is considered. At the same time, the considered building is operated with significant deviations from regulatory requirements. The causes of cracks in individual structures and cracks between individual elements in the building are found. The problem of the distribution of moisture in depth with local soaking is solved on the basis of a numerical method, and the character of soil moistening at different depths with different degrees of moistening and characteristics of the base soil is obtained.

Analysis of main points of channel freezing-thawing disease in cold region and influence of channel base soil on the disease

The frozen soil area in China is more than two thirds of the total territory, so the problem of frost heave is obvious. Especially in northeast, northwest, north China and other cold regions, the problem of frost heave of hydraulic structures is very common. Canal is a common hydraulic structure in agricultural water, which is affected by seasonal frozen soil and may cause problems such as lining damage, seepage and irrigation efficiency. Therefore, this paper mainly summarizes the necessity of research on channel freezingthawing damage, the research direction of channel freezing-thawing damage, and expounds the influence of seasonal frozen soil on freezing and thawing diseases in cold regions by taking the particle size of saturated soil based on channel as an example.

Criteria definition for high-rise buildings foundations deformation limitation

The article presents an overview of the foundation deformation limitation for buildings and structures. Information from main research, domestic and international construction codes is given. For high-rise buildings foundations deformation limits evaluation was done by analyzing architectural, technological, and structural requirements for high-rise buildings deformations and an estimation of a probable stochastic component of a non-uniform deformation which is related to statistically non-uniform of base soil. Statistical non-uniformity of base soil was modelled by the use of a simplified deterministic method. Defined criteria for high-rise building foundation deformation limitation can be used in future research.

Complexity of geotechnical problems in the process of revitalization of residential buildings

Revitalization of residential buildings is a process of renovation and improvement of the residential environment with the goal of providing users with a safe and healthy space in which to live. Through a series of necessary interventions and technical improvements, in the first phase of revitalization, the load-bearing structure, starting from the subgrade soil and foundations all the way to the top of the building, i.e. the roof structure, must be repaired and strengthened. The reinforced structure must guarantee the successful implementation of other planned phases of revitalization. The paper deals with geotechnical issues within which damages are registered, their causes are analyzed and measures for repairing the base soil and foundations are proposed. The problem is treated from the point of view of its complexity, the numerous causes of which are disscussed in the paper.