Dinamin Consulting - Eng. Dr. Ivan Daskalov

Letter to the Ministry 0001

by Assoc. Researcher Eng. Dr.  Ivan Daskalov
Dinamin CONSULTING Ltd.

Continuous history of human striving to reduce the severe consequences of earthquakes is closely related to how to determine their seismic impact (intensity). Currently this is done by the instrumental magnitude scale of Richter and by descriptive parts of the scales of intensity that has 12 degrees. Only Japanese scale Omori has seven degrees. Comparing the different scales of intensity is found that with the exception of Japan in the other scales there are a substantial overlap (1). Practically the first stage of Japan’ covers grades I and II of the twelfth stage, the seventh grade, respectively, XI and XII, while others have an appropriate overlap.

In principle the Richter scale shows by conventional units the separate seismic energy in the epicenter and the other defines the degree of intensity on the surface of earthquake. Using magnitude on the Richter gives a relatively realistic picture of the seismic intensity only in epitcentral area where soil conditions and depth of the seismic outbreak are equal. In other cases, the results can’t further be used as defined magnitude is constant and independent from the hypo-central distances and soil conditions on building sites.

Analysis of the descriptive parts of other scales indicates that they are elaborated after the systematization of a large number of observations associated with the reaction of people, damage to buildings and environmental impact. Because of their subjectivity these scales are continually adjusted and supplemented. When searching for a link between levels and registered physical quantities mainly paying attention to the maximum accelerations, velocities and amplitudes of displacement. It was found that a relatively close relationship in this direction is observed when using the speed of movement (2). However, the obtained results are not necessary for the practice accuracy. Therefore, to determine intensities on the surface are still used only descriptive parts of relevant scales.

Physical and mechanical point of view of seismic waves represents the process of transfer of deformation. It follows that the magnitude of these deformations on concrete construction sites most fully characterizes the seismic effects on them. Seismic waves undergo a dynamic terrain loading and unloading. According to wave mechanics, the relative deformations in this case are determined by the expression:

E=V/Cp                                                   (1)

Where:
E ( ) is the relative deformation in dynamic loading and unloading.
V is the velocity of movement, m/s.
Cp speed of spreading of longitudinal elastic waves, m/s.

From the expression (1) follows that only the registration of transfer speed is a necessary but not sufficient condition for determining levels of seismic effects (intensity). Instrumental and visual observations strongly suggest that in identical hipo-central distances and magnitude of earthquake, seismic impacts very substantially depend on the specific soil conditions on site. This is clearly illustrated by the different speeds of propagation of longitudinal elastic waves in the ground. Mainly for this reason in the rock sections relative deformations are much smaller than those in non rocky soil. Numerous studies indicate that the relationship between levels of seismic effects and relative deformation is the type:

I = 3,3219 lgE + 19,2876                (2)

Where:
I was the degree of seismic effects (intensity) in twelfth-degree scales (MM, MSK-64, EMS-98)

Despite substantial overlap analysis in the twelfth degrees scales showed that the most complete systematization of signs to determine effects of the turmoil on the ground, is seen in the scale MSK-64 and its supplements. After connecting descriptive parts of this scale of instrumental defined relative deformations caused by seismic waves then the scale becomes a descriptive tool and as a means MSK-64 D (deformation). Due to the fact that natural and technogenic earthquakes have common large upper in-variants fully applies to them (3). After comparison with that used in Japan seven-stage

scale in basis of which is that of Omori, the relationship between intensities and instrumentally recorded relative deformations yield the approximate form:

I = 2,222 lgE + 12,555                 (3)

where:
I was the degree of seismic effects (intensity) in seven-stage scale used in Japan.

Special practical interest is the comparison of the link, according to the expressions (1) and (2) with published dimensions conducted in the last 40 years in Sweden (4). So the first part of Table 1 are given the recommended speed of movement in different soil conditions characterized by the magnitude of the speeds of movements in different soils conditions, characterized the velocity spread value longitudinal elastic waves and observed damage in the typical residential buildings. In second part of the table are shown the results obtained under the expressions (1) and (2) upon the same sources. Although data from the first part of the table are represented in the widely observed margins there are lack of visible cracks in buildings to 3.53 degree, to the extent that small cracks 4.26, cracks visible to the extent and serious cracks 4.68 to 5.26 degrees. There is a clear full convergence of designated levels of seismic effects in the descriptive parts of twelve-stage scales. It should be noted that results obtained under the expressions (1) and (2) are significantly more detailed and correspond more fully with the descriptive parts of twelve-stage scales.

Descriptive-received instrumental scale has already successfully used to determine levels of seismic effects in the expected intensification of seismic focuses and regulation on the Richter magnitude of shocks to technogenic to safety level. Based on that new methodological approach is proposed for zoning Macro-seismic upon activation of outbreaks of Sofia, Kresna, Gorna and Popovishko-Chirpan seismogenic nodes (5,6,7,8). Established results are confirmed by the effects of already passed earthquakes in those areas. After adjustment of the magnitude on the Richter  in technogenic earthquakes located near existing facilities is provided seismic protection of sources of river. Zlatna Panega, reservoir “Lehchevo”, arched bridge of the south road junction of town of Veliko Tarnovo, the extension of the Sofia subway – Subproject  “Connector Dragan Tsankov”, the extension of WPS “Studen kladenz “and others.

Conclusions:

From the foregoing can be drawn the following conclusions:

1. Relatively close relationship between the instrumental registrations and descriptive levels of seismic effects (intensity) is observed when using the maximum values of the velocity movement. However, the obtained results do not bear necessary for practice accuracy. Therefore, to determine levels of seismic effects on the surface are still used only the descriptive parts of the relevant scales.

2. Necessary and sufficient condition for determining the rates of instrumental seismic impact is seen in the registration of the relative deformation in the dynamic loading and unloading due to seismic waves. On this basis was developed a descriptive instrumental scale that already is applied to natural and technogenic earthquakes.

3. After a small volume of preliminary exploratory work on the ground, which are located on seismic monitoring stations provide an opportunity for simultaneous registration of magnitude on the Richter and extent of seismic impact on this region. This yields a full dimension of the resulting earthquake phenomenon.

References:

1. Rijkova, Sn. “Earthquake – disaster and source of knowledge. “Technik”,Sofia, 1981
2. Newmark N.; Rosenblueth – Fundamentals of Earthquake Engineering. “Stroiizdat”, M. 1980
3. Daskalov, Ivan. Scale invariant in the study of turmoil. Magazine “Mining and Geology”, 5, 2004
4. Olofson, O.S. “Applied explosive technology for construction and mining”. Translated by “Dino Nitro Med” AD, 2005
5. Daskalov, Ivan; Minev, St., Kutzarov, B. “Conception assess the expected level of seismic effects onSofia” Magazine “Mining and Geology”, 4, 2003
6. Daskalov Ivan, “Opportunityto reduce the effects of seismic effects on Veliko Tarnovo” , Magazine “Mining and Geology”, 4, 2006
7. Daskalov, Ivan; Kutzarov, B. „Expected impact of the turmoil Macroseismic arising Struma zone” Annual issue ofMiningGeologyUniversity, 2007
8. Daskalov Ivan, “If an outbreak of stepped-Popovishko Chirpan seizmogenen unit”, Magazine “Mining and Geology”, 4, 2009

Assoc. Researcher Eng. Dr. Ivan Daskalov
Dinamin Consulting Ltd.

Formation and distribution of seismic waves is a result of releasing potential energy and using part of it for their generation. This energy in natural earthquakes is accumulated in the development of tectonic process and in explosion by a chemical and nuclear transfer. In principle, seismic waves are natural physical process of spreading in the environment of character variable deformations. Basic physical processes are examined by observation and re-creation /experiment/. In this case is possible re-creation upon generation of seismic waves caused by underground explosions. On this basis, has developed a methodical approach for determining the causal-consequence link between the released seismic energy and degrees of intensity.

It is known that investigations of complex processes are leading to representative results upon using methods of modeling in situ conditions through large-scale invariants. These are the values that remain constant regardless of the scale/size of the process. This method is applicable in this case. It is found that scale invariant is common to natural and technogenic quakes caused by underground explosion, as has been clarified and its physical nature (1). This provides an opportunity for comparing natural earthquakes with those caused by underground explosion, and a complete re-creation of the phenomenon. Thus establishes the connection between the seismic energy released in the earthquake foci /magnitude on the Richter scale/ and the distance to the epicenter of specific soil conditions on the surface. These conditions are characterized by the corresponding seismic stiffness /wave resistance/, which is a product of the environment density and the speed of propagation of longitudinal elastic waves in it. Practically outlines the following main groups of conditions: rock, semi-rocky, small-rocky and non-rocky with seismic stiffness respectively:

5,10х10⁶; 3,24х10⁶ ; 1,44х10⁶  и 8,00х10⁵  kg/m²s.

This is known that the values of seismic stiffness are in connection with the elastic module (Young’s modulus). From dynamic methods for its defining the most wide-spread received ultrasonic pulse method (2). Upon its usage the elastic module is determining by the expression:

After using the relation between tension in the dynamic loading and unloading and elastic module is obtained:

The expression (2) is well know and used in wave mechanics. The general form of the relationship between relative deformation and tension is illustrated by the figure 1:

Fig.1. Nomogram of tension-relative deformation in dynamic loading and unloading.

This relationship is linear only in the area of elastic behavior of the medium where dynamic loading and unloading takes place in the same law without formation and accumulation of residual deformations. This is the same and in case of the static load known as a low of Hooke. After the elastic zone dynamic loading and unloading takes place on different laws of formation and accumulation remaining deformation gradually reaching full seismic loss of stability. Whole that relationship when we present through the logarithm of relative deformation gains linear character.

From the foregoing it is seen that the relative deformation in the dynamic loading and unloading is directly related to strain and following that to the seismic energy in the place of registration. It follows that the registration only of the velocity of transfer is necessary but not sufficient condition for determining the seismic intensity. Thus, the relative deformation under expression (2) seems to be the most representative physical quantity defining levels of seismic intensity.

Providing the seismic stability by using registered relative deformations has been applied since 1978 (3). It has been proposed the permissible relative deformations not exceed than 0.0001, which is given by the expression:

V < 0.0001 Cp      (3)

Numerous of studies conducted in this direction in our country, including re-creating the phenomenon cover a range of intensity levels of descriptive 12-stage scales (4).

The link has next form:

I = 3,3219lge + 19,2876      (4)

where:
I    was the degree of seismic effects (intensity) in twelfth-degree scales (MM, MSK-64, EMS-98)
e  ( ) is the relative deformation in the dynamic loading and unloading on the site due to seismic waves.

Shortly presented methodical approach and the resulting relation between levels of intensity and the relative deformation in the dynamic loading and unloading caused by seismic waves is a development of methods for determining the seismic effects. Until now, this tool makes the Richter scale and descriptive parts of the scales of intensity, which have twelve degrees. Only the Japanese scale of seven is Omori degrees. Based on comparisons of different levels of descriptive scales with the exception ofJapan, there is a substantial overlap /5/.

Until now the Richter scale gives a relatively accurate picture of seismic intensity on the surface only in epicenter area under the same soil conditions and depth of seismic foci. In other cases, the results can not be used because the prescribed magnitude is constant regardless of hypo-central distances and soil conditions at construction sites. This crucial shortcoming is avoided in descriptive-instrumental scales. When performing small volume survey’ work on the area on which there are existing monitoring stations and determining the quantity of the velocity of longitudinal elastic waves – it allows a simultaneous registration of magnitude on the Richter scale and degree of intensity in the region. This would give the full measuring of the incurred earthquake.

The results of its application were confirmed by the effects of earthquakes that have been occurred in the activation of outbreaks in Sofia, Gornooryahovskiya, Kresna and Popovishko-Chirpan seismic nodes (6, 7, 8, 9). For example, the most powerful earthquakes recently upon activating of foci of Popovishko-Chirpan seismogen nodes became in 1928. The first quake with a magnitude M = 6,8 and a degree in MSHK IX has become 14.04.1928. and the second on 18.04.1928 with magnitude M = 7,1 and IX-X degree in intensity. After the first -demolitions in Chirpan and neighboring villages reached 100%, while those in Parvomay and surroundings up to 80%. After the second were almost complete destructions in town of Popovitsa and neighboring villages and large destructions in Plovdiv and its surroundings. The results obtained according to the developed methodological approach for four main groups of soil conditions are shown in Table 1.

Table shows the significant difference in the size of macro-seismic field depending on soil conditions and the quantity of their seismic stiffness. For the area most complete confirmation is observed for non-rocky and small-rocky and conditions of seismic stiffness respectively 8,00х10⁵ and 1,44х10⁶ kg/m²s as are the actually representative ones in the case. It should be noted that are defined and the maximum expected seismic effects of X’s in MSHK which till now have never been treated in the existing regulations, although these earthquakes have becoming again are expected.

Table 1. Dimensions of the transverse and longitudinal axes of the Macro-seismic field for IX and X degrees by MSK-D upon magnitude M = 7,1

Table 2. Levels of seismic effects of the occurred earthquakes compared to those using the developed algorithm. Confirmation of the results there are and in other studied regions. For example, seismic effects on the capital Sofia, where seismic stiffness primarily in the range of 8,00 х 10⁵ кg/m²s to 1,76 х 10⁶ kg/m²s, the main impacts are upon the activation of foci located in Sofia and Struma areas.

Shown results in Tab. 1 and 2 are in relation with Macro-seismic zoning. The second phase of the seismic zoning is Macro-seismic which includes instrumental earthquake diagnostic of construction sites. There are recording the relative deformations of dynamic loading and unloading during the generation of seismic waves from micro-explosion that couldn’t be felt by humans. Systematization of the results of both phases determines the specific seismic macro-zoning of studied object. Macro-zoning illustration of it was shown in tailings of Benkovski. In this case the most significant seismic effects are expected in the activation of seismic foci in the Struma, Sofia and Mariska areas.

Table 3. Results of Macro-seismic zoning of tailings Benkovski

The quantity of the relative deformation in the dynamic loading and unloading, which distorts adhesion between particles of tailings and it becomes liquid is not less than 8,32 in MSK-D. From the results of micro-seismic zoning shows that only intensify a focus in the Struma area of magnitude 7,8 is approaching the threshold value of relative deformation on tailings wall.

The developed methodological approach is widely used and provide seismic protection of objects located close to places where are conducted technogenic shocks caused by explosion. In this case the magnitude on the Richter scale is adjusted to a safe level of intensity upon MSHK-D. This has been done for a number of objects as sources of the Golden River Panega, reservoir “Lehchevo“, arch bridge south of Junction in Veliko Tarnovo, the extension of the metro – sub-connector “Dragan Tsankov”, the extension of HPP “Studen kladenez” and others.

Until now generally similar relationship was obtained only after processing the results of technogenic shocks caused by the explosion in the last 40 years inSweden/10/. Although in principle, it is a fully independent confirmation of the developed methodological approach and received practical results.

Application of developed descriptive-instrumental scale is included in the first stage of researches related to the conduct of earthquake prevention. This is an opportunity for pre-induction of a regulated energy release generated by developing tectonic processes in the subsurface. It is forming a trend than besides from static to open up enormous opportunities for dynamic effects as well/11/. Treated issues in general correspond with those of developed secret programs like “Mercury” objectives which are the creation of Geophysical /tectonic/ weapon that in scale and power superior nuclear power.

Therefore, there shouldn’t be distributed information for done researches because of the possibility to be used for antihuman purposes.

From the foregoing, may draw the following conclusions:

1. The developed methodological approach is based on the deformation characteristics of rocks and the fact that seismic waves are natural process of propagation of sign-variable deformations in them. Instrumentally recorded relative deformation in the dynamic loading and unloading has emerged as the most representative physical quantity defining levels of seismic intensity.

2. The total scale invariant of natural and technogenic shocks caused by an underground explosion, gives the opportunity to determine the relationship between the seismic energy released in the foci and relative deformations depending on the distance and the seismic stiffness / wave resistances / on construction sites.

3. The results of the application of methodological approach are confirmed with sufficient accuracy for practical purposes by the effects of earthquakes that have appeared naturally and of regulated technogenic shocks due to explosion.

4. Reveals the opportunity for instrumental of macro and micro-seismic zoning, providing a realistic assessment of seismic risk. This assessment covers the degree of X intensity as up to now wasn’t been treated in the research design of buildings and structures in earthquake areas. It should be noted that in activated in outbreaks/focuses of Kresna, Gornooryahovski, Popovishko-Chirpan and Shabla seismogenic nodes such events have taken places and are expected again.

5. The application of the developed methodological approach is related to research for the realization of earthquake prevention through pre-regulated release of energy, generated by the development of the tectonic processes.

Literature

1. Daskalov, I. Scale invariants in the study of earthquakes. Magazine Mining and Geology, 5, 2004.
2. Kolev, K. Physics of rocks and processes of destruction, ed. Tehnika, Sofia, 1982
3. Bogatskiy, V.F, V.H. Parchment. Сеисмическая безопасность при взрывных работах. Moscow, “НЕДРА” 1978.
4. Daskalov, I. A descriptive-instrumental scale of seismic activity, journal Mining and Geology, 2010, 1-2 ..
5. Rizhikova, Sn.; Earthquake disaster, and a source of knowledge. Publ Tehnika, Sofia, 1981
6. Daskalov, I., St.Minev B. Kutsarov. Conception’ estimate of the expected level of seismic impact Sofia .journal. “Mining and Geology” 4.2003.
7. Daskalov, I. Possibility to reduce the effects of seismic impact of Veliko Tarnovo. Magazine Mining and Geology “4.2006.
8. Daskalov, I., B. Kutsarov. Estimated macro-seismic impact of shocks arising in Struma zone. Annual of MGU, 2007.
9. Daskalov, I. If activates the outbreak of Popovishko-Chirpan seismogenic node. Magazine Mining and Geology “4.2009.
10. Olofson Stig. Applied explosive technology for construction and mining. Translation Dino Nitro Med, 2005.
11. Daskalov, Ivan Possibilities for making earthquake prevention. Magazine Mining and Geology, 10, 2005.

Summary

It is considered a new methodical approach to determine the relation between seismic energy and intensities, which includes re-creating of the phenomenon. The results obtained from its application are confirmed with sufficient accuracy for practical purposes by the effects of already occurred naturally and technogenic shocks caused by the explosion.

by. Assoc. Researcher Eng. Dr.  Ivan Daskalov
Dinamin CONSULTING Ltd.

Here I would like to show you a comparison of used in Japan the seven degrees scale of intensity with twelve degrees scale MSHK-D. The comparison was developed using the quantities of relative deformation in dynamic loading and unloading of the environment caused by seismic waves.

The analysis shows that the values of the relative deformation MSHK-D increased exponentially by a 
factor 2.0 upon increasing the intensity with a notch. Practically covered interval is almost the
same as it is in seven degrees scale by a factor of geometric progression 2,7. On this basis we’ve
obtained the approximate relation between degrees of intensity in scale applied in Japan and the
relative values of the deformation that has the form :

I=2,318lgЕ + 12,782   (1)

where:
I was the degree of seismic effects (intensity) in seven-degree scale applied in Japan
Е ( ) is the relative deformation in the dynamic loading and unloading on the site/environment due to seismic waves

Established already relation between degrees of intensity and values of relative deformation upon dynamic loading and unloading caused by seismic waves according to the MSHK-D has the form:

I = 3,3219lgЕ + 19,2876   (2)

where:
I was the degree of seismic effects (intensity) in twelfth-degree scales;

To illustrate the comparison between results upon expressions (1) and (2) I’ve used published data for an earthquake occurred at August 11, 2009 at Japan with magnitude M=6.5 and intensity 5.0; 4.6; and 3.5 respectively at epicenter’ distances 25, 43 and 98km.

Results:

It is known that soil conditions on the ground are characterized by their seismic stiffness /wave resistances/ representing product of the environment density and the speed of propagation of longitudinal elastic waves in it.  Practical outlines the following main groups of soil conditions:

Rocky, semi-rocky, small rocky and non-rocky. The corresponding seismic stiffness are 55,10х10⁶;  3,24х10⁶;  1,44х10⁶; and 8,00 х 10⁵ kg/m²s.  Resulted degrees of intensity upon MSHK-D with magnitude M = 6,5 for epicenter’ distances 25, 43 and 98 km in the four groups of soil conditions are given in Table 2:

The resulting degrees of intensity MSHK-D from both tables show that there is enough practical cover for non-rocky soil conditions with seismic stiffness 8,00 х10⁵kg/m²s, to the relevant epicenter’  distances. That ultimately may be determined by instrumental method and relevant researches in the places where they were located observation stations.

The new methodical approach in determining the causal relation between the released in the foci seismic energy and the quantities of relative deformations in dynamic loading and unloading of the environment (though in a preliminary stage) reveals significant opportunities to reduce the severe consequences of the expected earthquakes. So, with greater accuracy could be determined prior seismic effect and seismic risk based on the instrumental macro and micro zoning.

Sofia, Bulgaria

+359 888 203 205  (for English speaking)

+359 898 458 300 (for Bulgarian speaking)

e-mail: dinamin_co@abv.bg

Sofia, Bulgaria

+359 888 203 205 (for English speaking)

+359 898 458 300 (for Bulgarian speaking)

e-mail: dinamin_co@abv.bg