Solving a direct problem as a new method of seismic microzonation

2021 ◽  
pp. 38-53
Author(s):  
Alexander S. Aleshin ◽  
Vladimir V. Pogrebchenko ◽  
Sergey N. Nikitin
Keyword(s):  
Direct Problem ◽  
Water Saturation ◽  
Soil Layer ◽  
Seismic Intensity ◽  
Seismic Microzonation ◽  
Acceleration Pulse ◽  
Territorial Planning ◽  
New Type ◽  
Seismic Impact ◽  
Seismic Impacts

The article describes a new type of seismic microzonation, called the method of solving a direct problem. The main methodological technique in this case is the formation of models of the soil layer on the basis of complex engineering-geological and geophysical studies. An original computer simulation technique based on the use of a short acceleration pulse as the initial seismic impact is proposed. In the calculations of the increment of seismic intensity, a new formula is used that takes into account all the factors of the influence of soil properties on the parameters of seismic impacts – seismic rigidity, water saturation, resonant effects and the nonlinearity of the reaction of soils to strong seismic impacts. Based on the obtained data, the models of ground layers at the construction site are mapped and the parameters of seismic impacts that correspond to the properties of each model of ground massif are determined. The proposals presented in the article are reflected in the regulatory documents devoted to the SMZ of objects of increased responsibility and territorial planning.

The antiresonance phenomena in seismic microzonation

2021 ◽  
pp. 8-18
Author(s):  
Alexander S. Aleshin
Keyword(s):  
Seismic Waves ◽  
Seismic Intensity ◽  
Seismic Microzonation ◽  
Seismic Impact ◽  
Seismic Impacts

The interference of incident and reflected seismic waves in the ground massif near the day surface is the cause of resonant effects. In the practice of seismic microzonation (SMZ), a resonant increase in the total seismic intensity is of particular importance. At the same time, the presence of inverse layers in the ground layers interference leads to a decrease in the intensity of the total seismic impact, what is naturally named antiresonance. The article considers the conditions for the occurrence of antiresonance and evaluates the limits of its effectiveness. The natural and man-made causes of antiresonance and the possibility of using it to reduce the intensity of seismic impacts are particularly noted.

scholarly journals Calculation of the Height of Capillary Rise of Water in Soils

2020 ◽  
Vol 8 (6) ◽  
pp. 4832-4835
Keyword(s):  
Water Saturation ◽  
Underground Structure ◽  
Capillary Rise ◽  
Soil Layer ◽  
Underground Water ◽  
Wall Material ◽  
Capillary Water ◽  
Temporary Streams ◽  
Filter Water ◽  
Soil Pores

Rain and melt water will form temporary accumulations of surface water on the surface. When they seep into the ground, temporary streams of leaky filter water are formed. If a limited section of water-resistant soil layer or the roof of an underground structure is encountered in the path of these waters, a temporary aquifer-the upper layer of ground water-may form above them. In temporary and permanent aquifers, the soil pores are completely filled with gravitational water, the degree of water saturation is equal to one, and there is pressure under the surface of underground water. Above this surface is a zone of capillary moisture, while the level of capillary rise is determined by the granulometric composition of the soil and ranges from tens of centimeters in sand to several meters in dusty and clay soils. Capillary water rises in the ground on free canals formed by mutually communicating pores, or is kept in them in limbo.The lifting of the liquid in the capillary continues until the gravity acting on the column of the liquid in the capillary becomes equal to the resulting force. Capillary water penetrates from the ground into the walls and rises to a height of up to 2 meters. The normal moisture content of the brick walls is 0.02...0,03, and in the case of unprotected contact with moist soil is increased to 0.15...0.25. On the inside of the walls there is a damp, mildew. Evaporating water increases humidity in the room, and the salts released when it evaporates from salt solutions lead to peeling paint, destruction of plaster and wall material.

scholarly journals Response Site Analyses of 3D Homogeneous Soil Models

2018 ◽  
Vol 2 (5) ◽  
pp. 238 ◽  
Author(s):  
Davide Forcellini ◽  
Marco Tanganelli ◽  
Stefania Viti
Keyword(s):  
Soil Type ◽  
Soil Depth ◽  
Site Response ◽  
Soil Layer ◽  
Shear Velocity ◽  
Seismic Intensity ◽  
Eurocode 8 ◽  
Seismic Input ◽  
Homogeneous Soil ◽  
Response Site

The seismic excitation at the surface can be determined through Site Response Analyses (SRA) as to account for the specific soil properties of the site. However, the obtained results are largely affected by the model choice and setting, and by the depth of the considered soil layer. This paper proposes a refined 3D analytical approach, by the application of OPENSEES platform. A preliminary analysis has been performed to check the model adequacy as regards the mesh geometry and the boundary conditions. After the model setting, a SRA has been performed on various soil profiles, differing for the shear velocity and representing the different soil classes as proposed by the Eurocode 8 (EC8). Three levels of seismic hazard have been considered. The seismic input at the bedrock has been represented consequently, through as much ensembles of seven ground motions each, spectrum-compatible to the elastic spectra provided by EC8 for the soil-type A (bedrock). Special attention has been paid to the role of the considered soil depth on the evaluation of the surface seismic input. Different values of depth have been considered for each soil type and seismic intensity, in order to check its effect on the obtained results.

scholarly journals Formation Mechanisms of Snow Crystals at Low Temperature

1985 ◽  
Vol 6 ◽  
pp. 232-234 ◽  
Author(s):  
Noboru Sato ◽  
Katsuhiro Kikuchi
Keyword(s):  
Water Saturation ◽  
Diffusion Chamber ◽  
Formation Mechanisms ◽  
Polar Regions ◽  
Maximum Frequency ◽  
Growth Mechanisms ◽  
New Type ◽  
Number Frequency ◽  
Snow Crystals ◽  
A Minor

To study crystal shapes, and formation and growth mechanisms of snow crystals formed below -20 °C, a new type of diffusion chamber was constructed. Using this chamber, different kinds of “peculiar shaped” crystals previously observed in nature have been produced, together with normal types of snow crystals. Gohei twins, one of the most typical polycrystalline shapes in nature, have been produced artificially. The vapor pressure was at or near water saturation at the time of nucleation. Analysis of photomicrographs and replicas of Gohei twins that were replicated in the polar regions show that the number frequency of the tip angle has a maximum frequency at about 77° and a minor one at about 54°.On the basis of these results, a formation mechanism for some Gohei twins is proposed in this paper.

scholarly journals A new type seismic intensity meter

2014 ◽  
Vol 5 (4) ◽  
pp. 73-78 ◽  
Author(s):  
Li Xin ◽  
Guo Tangyong ◽  
Xia Jiening ◽  
Zou tong ◽  
Zhu Wei ◽  
...  
Keyword(s):  
Seismic Intensity ◽  
New Type

scholarly journals METHODS FOR CALCULATING DYNAMIC SYSTEMS WITH ELASTOMERIC SUPPORTS UNDER SEISMIC IMPACTS OF THE "PROJECT EARTHQUAKE" LEVEL»

2020 ◽  
Vol 8 (3) ◽  
pp. 23-28
Author(s):  
Maksim Zubrickij ◽  
O. Ushakov ◽  
Linar Sabitov ◽  
A Sagabiev
Keyword(s):  
Surface Area ◽  
Dynamic Systems ◽  
Dynamic Method ◽  
Main Tool ◽  
Seismic Stability ◽  
Earthquake Resistant ◽  
The Difference ◽  
Seismic Impact ◽  
Isolated Systems ◽  
Seismic Impacts

The article provides a brief overview of methods for assessing the seismic stability of systems using elastomeric supports under seismic impacts of the "Project earthquake" level. As part of the study, a set of dynamic and static calculations was performed, and two methods for calculating earthquake-resistant systems were considered: the linear-spectral method (LSM) and the direct dynamic method (PDM). The purpose of the research is to assess the possibility of using LST for seismic impacts of the PZ level on systems with elastomeric supports. It was found that the difference in the results of calculations for the two methods does not exceed 12 %. Thus, the SHEET can be used as the main tool for calculating seismically isolated systems under the seismic impact of the earth's surface area.

SEISMIC COLLAPSING ANALYSIS OF THREE-STORY WOODEN HOTEL

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Tomiya Takatani ◽  
Hayato Nishikawa
Keyword(s):  
Strong Earthquake ◽  
Surface Soil ◽  
Process Analysis ◽  
Ground Motions ◽  
Soil Layer ◽  
Seismic Intensity ◽  
Earthquake Ground Motion ◽  
Earthquake Ground Motions ◽  
Old Japanese ◽  
Upper Level

A 3-D collapsing-process analysis of an old Japanese-style 3-story wooden hotel under strong earthquake ground motions was carried out with three seismic intensity levels to investigate its seismic performance. Three earthquake ground motions were evaluated from three ground boring data around this wooden hotel, using the non-linear amplification characteristics of surface soil layer above the engineering base rock. As a result, this wooden hotel collapsed against a strong earthquake ground motion with JMA seismic intensity of a “6 upper” level.

Principle of WaveSonic Logging Tool and Application

2014 ◽  
Vol 962-965 ◽  
pp. 856-859
Author(s):  
Ji Hui Feng
Keyword(s):  
Quality Control ◽  
Case Studies ◽  
Water Saturation ◽  
Well Logging ◽  
New Type ◽  
Technical Specifications ◽  
Logging Tool

The configuration and technical specifications of the new type WaveSonic Logging Tool bought by West Drilling Well Logging Company are introduced from Halliburton Company.It shows that the consistency,repeatability and stability of the tool are good,and its specifications fully meet pre-designed requirements and quality control standards. In this paper, WaveSonic logging principles are briefly introduced, applications case studies to porosity, permeability, and oil and water saturation are discussed in details.

scholarly journals Seismic impacts influence on the slope stability on the example of Abrau Peninsula (Russian sector of black sea coast)

2020 ◽  
Vol 157 ◽  
pp. 02022
Author(s):  
Mihail Kropotkin
Keyword(s):  
Slope Stability ◽  
Seismic Waves ◽  
Seismic Effects ◽  
Stability Calculation ◽  
Black Sea Coast ◽  
Russian Sector ◽  
Seismic Accelerations ◽  
The Stability ◽  
Seismic Impact ◽  
Seismic Impacts

Some aspects of seismic impact on the stability of massive seismogravitational solid masses are examined. An example of the slope stability calculation using separate accounting for seismic accelerations in blocks is shown. The influence of the relief on the change in seismic effects is considered. Some aspects of seismic impact on the stability of massive seismogravitational solid masses are examined. An example of the slope stability calculation using separate accounting for seismic accelerations in blocks is shown. The influence of the relief on the change in seismic effects is considered. The comparative impact of longitudinal and transverse seismic waves from the earthquake focuses located in front of the slope foot and behind the slope ridge is evaluated.

The Study on Seismic Reliability of CS Panel Structure

2011 ◽  
Vol 368-373 ◽  
pp. 154-158
Author(s):  
Yan Bo Li ◽  
Chuan Fu Xu ◽  
Xue Yan Wang
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Seismic Intensity ◽  
Experimental Models ◽  
Element Analysis ◽  
Seismic Reliability ◽  
Dynamic Reliability ◽  
Failure Theory ◽  
New Type ◽  
Set Up

CS Panel Residential Structure is a new type of structural system investigated and manufactured for the requirements of wall reformation and residential industrialization.Now set up two finite element models on the basis of the two types of three storeys CS panel structure experimental models (including tectonic columns or not ) with the ratio 1:2.8 that designed before. Then analyze the random seismic response of the two types of CS panel structure under the action of ground motion acceleration power spectrum using the spectrum analysis module of the finite element analysis software ANSYS.Based on the first excursion failure theory and stochastic vibration theory, dynamic reliability of the CS panel structure subject to different seismic intensity is calculated and compared, the effect of the edge component is summarized using structure seismic response of random statistic.

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