The criterion of block media strength and geomechanical back-calculation

Relevance and problematics. The mechanism of block medium and jointed rock mass deformation and breaking differs notably from continuum mechanics ideas, making up the crucial fundamental problem of geomechanics and distinguishing it from other engineering sciences connected with the mechanics ISSN 0536-1028 «Известия вузов. Горный журнал», № 6, 2020 47 of deformable solids. However, due to poor understanding of block media breaking mechanism, rock masses strength is overwhelmingly estimated by means of empirical dependences obtained by simulation in laboratory conditions. It is apparent that this approach does not solve the crucial fundamental problem and the accuracy of predicting mechanical characteristics of jointed rock masses may reach 100%. Research methodology. Based on the earlier theoretical research by the methods of variational, integral, and differential calculus, a new mechanism of block mass breaking at a point was substantiated. It implies translation and rotational character of blocks displacement in a rock mass in the process of its deformation making it possible to substantiate the criterion of jointed rock masses breaking. Research results, analysis and recommendations for use. The research was the first to obtain the block medium strength criterion. It has been shown that block mass strength is made up of the strength along the slip joint and block rotation resistance. Besides, within some range of loads, the ultimate strength of the rock mass is proportional to the tensile strength of a structure block. The work also proposes a range of analytical dependences obtained based on the solid mechanics making which make it possible to back calculate the rock mass strength based on the curvature of the shear rupture surface and assess the full tensor of the plain field of strain by the base axes orientation.

MAPPING SETTLEMENT QUALITY AND HEALTH CONDITION IN COASTAL AREA OF JEPARA DISTRICT 2019

<p><em>The research Purposes is 1) Knowing coastal settlement quality at jepara district 2) Knowing coastal health condition level society 3) Knowing the correlation settlement quality between health level condition at Jepara District. The method used in this research is descriptive quantitative with spatial approach, the population in this research is settlement located at coastal area of Jepara District in 5 villages Demaan, Bulu, Kauman, Jobokuto, Ujungbatu. Technical sampling used proportional random sampling. Based on the result of the research the conclusion of the research is (1) settlement quality in coastal is on the good classified and medium classified for 34 settlement block which proportion 8 block is good classified and 26 block medium classified. The methode used is sattelite images interpretation and terrestrial. (2) health level condition in coastal has a various level from high classified and low classified if it is seen from incident rate of 5 diseases, based on administration demaan has the IR of 13,03 (low), Bulu 25,16 (high), Kauman 16,37 (low), Jobokuto 19,35 (normal), Ujungbatu 18,05 (normal) it shows that Demaan village has IR 13,03 it means there are 13 people which has illness out of 100. (3) correlation between settlement quality and health level condition in coastal has same direction but not too significant, with correlation value 0,275 (enough). correlation health level condition not only caused from settlement quality but it caused by many factor in that area.</em></p>

Strains analysis at the wave propagation throught he contact layer of the elastic solids

The stress-strain state on the interface of the elastic solids is investigated. The studied interface presents a contact layer which is characterized by dimension and the set of physics mechanical parameters. The models of layered and block medium are used for the description this boundary. In the framework of these models the problem of elastic wave propagation through the interface is considered. Analytical expressions for the refraction and reflection coefficients allowing us to determine the strains on the interface and strains distribution in the contact layer are found. Corresponding strains amplitudes depending on the layer thickness are calculated at the different elastic parameters of contacting solids and boundary. The strain laws on the interface which is described by the layered and block medium models are analyzed. The regions of equivalent use these models are determined in the case of strain analysis on the boundary and the strain distribution in the contact layer.

METHODOLOGICAL APPROACHES TO DETERMINING THE STATE OF BLOCK SEISMOGENIC MEDIUM ON THE EXAMPLE OF THE 2008-2011 SEISMIC ACTIVATION IN THE CENTRAL PART OF THE BAIKAL RIFT

Based on the joint analysis of the seismic regime parameters, such as anomalies of seismic energy release, b-value, seismic activity A10, approaches to assess the state of the block-seismic medium are proposed. The method validation was done for the example of preparation and development of seismic activity in 2008-2011 in the Central part of the Baikal rift, during which there were 2 strong M5.3 earthquakes. It was found that within 2 years before the strong Maximihinskoye Earthquake of 2008 in the Earth's crust of the epicentral region there is a transformation from softening to strengthening (consolidation) of the block medium. At the same time, in the neighboring region (the area of the Svyatoy Nos Peninsula), the opposite nature of the changes is observed.