University of Kirkuk كركوك جامعة

College of science كلية العلوم

Dept. of applied geology االرض علوم قسم التطبيقية

في رسوبية صخور لنماذج الديناميكية الصفات بعض و الزلزالية السرع ايجادالعراق شمال ازمر جبال سلسلة منطقة

مقدم بحثبكالوريوس شهادة نيل متطلبات من كجزء

التطبيقية االرض علوم في علوم

قبل من

كريم فؤاد جنيدعثمان خالد دنيا

اشراف

1

علي. ا خليل ظاهر

Six samples had been chosen from balambo formation in azmar mountain/sulymaniyah north of iraq for the purpose of conducting tests about dynamic properties of the rock samples, by using the ultrasonic device (matest) we obtained the Vp,Vs for the rock samples. Then we measured the density, bulk module, young module, poisson ratio, anisotropy and other dynamic properties.

Mathematical and statistical relationships has been drawing for the rock samples properties, most of them was in directed proportional.

The sample of highly marly content (marly limestone) sample has the higher bulk modules value and lowest shear modules and Vs, in the other hand the sample calcite vine has the higher Vp and Vs.

The benefit behind our research is to know the rock strength in the area for geological and engineering purposes.

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Abstract

Chapter one page no.

1-1 Introduction…………………………………………………………………………………………………….............5

1-2 Studied area……………………………………………………….............................................…..………………6

1-3 Aim of the study…………………………………………………………………………………………………….......6

1-4 Previous studies……………………………………………………………………………………………………….7

Chapter two

2-1 Theory background……………………………………………………………………………….………...8

2-2 FEATURES INFLUENCING THE MAGNITUDE OF LONGITUDINAL SONIC VELOCITIES…….

2-2-1 Factors influencing the sonic velocities in intact rock……………………………………..

2-3 EARLIER METHODS USED TO CHARACTERIZE ROCK MASSES FROM SEISMIC VELOCITIES……….

2-3-1 Connections between jointing and seismic velocities…………………………..

2-3-2 Rock quality estimated from the seismic velocity ratio……………………..

2-3-3 Correlations between seismic velocities and rock mass characteristics…………

Chapter three

3-1 Field work……………………………………………………………………………….………....16

3-2 lab work………………………………………………….

Chapter four

4-1 Results of physical and dynamics tests…...20

4-2 Statistical mathematical relationships………….

4-3 Conclusion…………………………………………………………………………………………………..…24

3

LIST OF CONTENT

Fig. 1 …....study area

Fig. 2…….p wave

Fig. 3…… S wave

Fig. 4…..Rayleigh wave

Fig. 5…… Love wave

Fig. 6….. Average regression curve of the correlation between longitudinal sonic velocity (v) and joint density

Fig. 7…..the out crops where the blocks picked

Fig.8……. relation between Vp and E

Fig.9…… relation between Vp and density

Fig.10……relation between Vp and lama

Fig.11…. relation between Vp and G

Fig.12…. relation between Vp and K

Fig.13…… relation between Vp and poisson ratio

Fig.14…. relation between Vs and G

Fig.15…..relation between Vs and density

Fig.16…..relation between Vs and poisson

Fig.17…. relation between Vs and E

Fig.18…… relation between Vs and k

Fig.19… relation between Vs and lama

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List of figures

Table 1………..longitudinal velocity of some minerals

Table 2………typical ranges of longitudinal sonic velocities for intact rocks

Table 3…….average sonic velocities for intact rocks

Table 4……….approximate connections between refraction seismic velocities

Table 5……….relationships between tunnel support category and seismic velocity ratio

Table 6…… results of the dynamic properties

Table 7……..results of the anisotropy calculation

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List of tables

1-1 introduction

Generally, the velocities depend on the elastic modulii and density these elastic constants, and densities, in turn depend on the properties that the geologist or engineer use to characterize the rock such as porosity, fluid saturation, texture etc.

A review of the relationships between the intrinsic rock properties and the measured velocities or reflectivity’s is needed before seismic survey results can be interpreted quantitatively in terms of lithology. Many of these relationships are empirical – velocities are found to be related to certain rock units in a given locale by actual laboratory measurements on core samples of the rock or soil. It is observed from seismic surveys that velocities generally increase with depth. Densities also increase with depth so it must be that the bulk and shear modulii increase faster than the density. In seismic exploration there are many empirical relationships between velocity and depth of burial and geologic age.

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Chapter one

1-2 studied area

The study location in the north of Iraq azmar mount/Sulaymaniyah latitude 35°37'42.29"N longitude 45°28'36.41"E.

Figure (1) study area azmar mount/north of Iraq

1-3 aim of the study

1- Determine the dynamic properties of the rocks such as (poisson ratio, bulk modulus, modulus of elasticity, Lama Constant, and modulus of Rigidity.

2- The characteristic of the rocks from these dynamic properties. Such as porosity, texture, fluid saturation, density etc…

3- Determine the anisotropy.

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1-4 previous studies

1-4-1 Studies the physical properties of the rocks and Geotechnical outside Iraq:-

Investigated of Hamdi and Taylor (Hamdi & Taylor, 1982) about the impact of permeability in the transmission of seismic waves in marine sediments and depending on the equation Piot (Biot Equation), The researchers used several frequencies to study the porosity and permeability of the sediments, and the results showed that the speed increases with the use of frequencies (0-1 MHz) and increase the size of grains of sand (Sand) to fine sand (Fine Sand) with a slope value of porosity.

Study of Gleese (Gilles, 2000) in search of chalky layer opals and rocks in New Jersey in the United States , through the study of seismic shear velocities in the field, and the qualities of flexibility for deposits of porous low-lying and high ,The sample that has been studied could provide information about the characteristics of flexibility and speed shear through sensors standard that have an impact in the study variables sedimentary Althoiria (Diagenetic), and concluded that the impact of changes sedimentary Althoiria factor sternal make Jesse speed sternal accurate indicator of the size of the voids and the type of material in them.

Juliet and Kokonyn (Joeleht & Kukkonen, 2002) studied the qualities petrophysical 's ( 364 ) model of the sedimentary rocks in Estonia , and for the purpose of studying how different qualities rocky different kinds of Alcarbonatih ( limestone , and dolomite , and Marl ) and clastic ( stone , sand, and silt , stone and clay ) . The results showed that the porosity is basically the index factor in porous rocks on the physical properties included in the study: the thermal conductivity, density and humid, and the speed compressibility, and electrical resistivity.

Study of McCann and others (McCann et al., 2004) in search of the University (Reading) in the UK (United Kingdom) about the relationship between the qualities of petrophysical and opposition voice and mineral rocks were examined to identify the reservoir hydrocarbon in the bottom of the sea.

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1-4-2 Studies the physical properties of the rocks and Geotechnical in Iraq:-

Study of qahwaji (1989) in Mishraq rocks aperture taken from five wells included: the physical characteristics and properties of Geotechnical dynamic and static short-term with tissue stone marl, lime, gypsum, and showed that the tissue rocky affect the mechanical properties, and among the rocks of gypsum and limestone possesses qualities of static medium resistance compressibility, either marl, it is weak and the statistical relationship between the various qualities. Well as the development model of the speed of ultrasound layers of rock (Velocity Layer Model), for the purpose of identifying and synthetic seismic model of the search area.

Sultani (1992) studied recipes and rocks Haklaa laboratory in northern Iraq , has been assessing the validity of the rocks ( marble ) and the possibility of investing as mine , and studied stratified search area after creating samples . Been testing Geotechnical and laboratory rock formation (Akre - Bekhme) as well as the physical characteristics and dynamics, and concluded that the possibility of charge density appropriate to the work of the bombing of the rocks of the expense of anti- acoustic and expected resistance value sternal cohesion and angle of internal friction in a way Wrecker approximate, and the validity of marble.

Investigated of (Toma, 1992) rocks of the foundation (foundation) in bridging Badush studying the geological rock dolomite and limestone the composition of follicular , and included the study of fractions and analyze the chemical and metal tests conducted geotechnical and physical ( Density, porosity , and swelling emotion ) and tests dynamics (speed compressibility , and sternal ) , mechanical , and found relationships between these attributes , including a good relationship between porosity and velocity compressibility.

The Asadi (2004) study about formation of the hole in the rocks village Alzakh - east of Mosul, a limestone and clay and gypsum and sand and mud. Also conducted measurements for hardness and vulnerability processes of weathering and classified on the basis of the proportion of pulp quality rock (RQD) and the degree of cracking, and conducted tests physical and mechanical and absorption of water and the method used ultrasound accelerated seismic longitudinal and shear factors flexibility dynamic, as well as factors static, and painted the relationship between these traits. And

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classified limestone being very weak and coefficient ratio (ED) high - weak and gypsum rocks were too weak and the ratio coefficient (ED) moderate - weak, and painted the relationship between stress - strain for a number of samples.

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2-1 Theory background

2-1-1 Wave types:-

1-body wave:-

• Seismic waves which travel through the body of the medium. Body waves are classed as either P-wave or S-waves.

P-wave

Compressional waves,Particle motion in directionOf propagation fig 2.

Figure 2 p wave

S-waves

Transversal/shear waves,

Particle motion perpendicular

To direction of propagation fig 3.

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Chapter two

Figure (3) S wave

2-surface wave:-

• Seismic waves which travel along or near the surface of a body, with motion that decays rapidly with distance from the surface. Surface waves travel with slower velocities than body waves.

Rayleigh-waves

A surface wave whose particle motion is elliptical and retrograde in the vertical plane containing the direction of wave propagation. In land exploration known as Ground Roll fig 4.

Figure (4) Rayleigh wave

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Love-waves

A surface wave associated with the surface layer which is characterized by horizontal motion perpendicular to the direction of propagation with no vertical motion. Fig5.

Figure (5) love wave

2-2 FEATURES INFLUENCING THE MAGNITUDE OF LONGITUDINAL SONIC VELOCITIES:-

In the field there are several factors that, in a complex way, may influence the propagation of sonic velocities (Palmstrom.B.K, 1955) . The main contributions stem from:

• The inherent properties and condition of the rock material consisting mainly of:

- Rock type (mineral content, texture, density, porosity, anisotropy);

- Weathering or alteration of the rock material;

- Saturation;

- Pressure; and

- Temperature.

• The in situ conditions, with the main contributions from:

- Distribution of rock types;

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- Quantity of joints;

- Joint openings;

- Rock stresses; and

- Ground water condition.

The most important of these factors are briefly discussed in the following.

2-2-1 Factors influencing the sonic velocities in intact rock:-

Velocities of longitudinal waves vary considerably with the type of rock. A representative selection of typical longitudinal (compressional) sonic velocities is given in Tables 1, 2 and 3.

TABLE 1 LONGITUDINAL VELOCITY OF SOME MINERALS.

Mineral Mineral Vm (km/s)calcite 6.6

dolomite 7.5gypsum 5.2quartz 6.05

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TABLE 2 TYPICAL RANGES OF LONGITUDINAL SONIC VELOCITIES FOR INTACT ROCKS.

TABLE 3 AVERAGE SONIC VELOCITIES FOR INTACT ROCKS.

Compact rocks

(km/s) Less compact rocks

(km/s) Unconsolidated rocks

(km/s)

dolomite 5.5 Limestone 4 sand 1

Slate and shale

4

sandstone 3

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2-3-EARLIER METHODS USED TO CHARACTERIZE ROCK MASSES FROM SEISMIC VELOCITIES:-

Although there is a clear correlation between jointing and seismic refraction velocities, the latter also includes the averaged (Lama, R.D & Vutukuri, V.S, 1978) effect of other factors such as rock properties and stress conditions as further dealt with later in this section.

TABLE 4 APPROXIMATE CONNECTIONS BETWEEN REFRACTION SEISMIC VELOCITIES, ROCK MASS CONDITIONS AND ROCK SUPPORT IN SCANDINAVIAN TUNNELS.

2-3-1 Connections between jointing and seismic velocities:-

In Scandinavia, an approximate method to utilize seismic velocities measured in the field to estimate rock mass quality and tunnel support requirements has been frequently used for 30 years. Concludes that "It can be said almost without exception that on the surface of the hard crystalline bedrocks of Sweden seismic velocities of 4000 m/s or less are indicative of weak zones in the bedrock. Stretches on a profile with such a velocity thus can be considered

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to be weak zones without further question, provided the surrounding higher velocities are greater than 4900 m/s."

An example of a classification often used in Norway is shown in Table 4. It should be noted that this classification is crude and that it is related to unweather, hard, crystalline rocks. The method may in many occasions be inaccurate and even wrong.

2-3-2 Rock quality estimated from the seismic velocity ratio:-

Some authors have compared in situ velocities of longitudinal waves in the rock mass with the velocity of intact rock cores tested in the laboratory in order to characterize rock quality.

The 'Seismic Velocity Ratio'is defined as:-

SVR = Vf /Vr

Where VF is the longitudinal seismic wave velocity measured in the field, and Vr is the basic sonic wave velocity measured in the laboratory.

For a massive rock mass containing only a few joints, the velocity ratio (Vf /Vr) should approach unity; but as the degree of jointing becomes higher, (Vf /Vr) will be reduced.

The squared seismic velocity ratio named 'Velocity Index' VI = (Vf /Vr) ^ 2 of is comparable to SVR. The ratio has been squared to make the velocity index (VI) equivalent to the ratio of the dynamic moduli.

Table 5 illustrates the relationship between the velocity index, velocity ratio and rock mass quality. Did not find that the squaring of the seismic velocity ratio had any advantages over the first power of seismic velocity ratio (SVR) other than a wider numerical band for the intermediate support category.

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TABLE 5 RELATIONSHIPS BETWEEN TUNNEL SUPPORT CATEGORY AND SEISMIC VELOCITY RATIO.

2-3-3 Correlations between seismic velocities and rock mass characteristics:-

A vast amount of experience has been gained from more than 30 years with refraction seismic measurements in Scandinavia. Sjögren et al. (1979) have from a comprehensive investigation of field measurements shown correlations between seismic velocities and joints measured in drill cores taken in seismic profiles.

The investigation comprised 113 km of refraction seismic profiles and 2850 m of drill cores from 8 sites in unweather, igneous and metamorphic rocks such as amphibolite, granite, gneiss, meta-anorthosite, pegmatite, porphyry, quartzite, and mylonite. From the results they have equated longitudinal seismic velocity with 1-D joint frequency in boreholes as shown in FIG 6.

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FIG (6) Average regression curve of the correlation between longitudinal sonic velocity (v) and joint density. The curve is derived from 5 sites comprising igneous and metamorphic rocks with 1670 m of cores.

The curve in Fig. (6) May be representative for jointed unweather hard, crystalline rocks near the surface. The high velocities are well represented in the curve, but for velocities below about 3500 m/s the data are more scattered. The curve may, therefore, be less representative in this part. Additional uncertainties may stem from the fact that logging of drill cores is generally less accurate in highly jointed and crushed rock. Proposed a multiplication factor of 0.8 for the higher in situ velocities in order to overcome this problem.

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3-1 Field work:-

In order To provide samples for our project we had a trip to Mount Azmar in the city of Sulaymaniyah, where samples had been taken from a different outcrops for the same formation which was balambo formation using a geological hammer, samples were taken in the form of blocks In order to ease cut later in the laboratory as shown in the figure (7).

Figure (7) the out crops where the blocks picked

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Chapter three

3-2 Lab work:-

Samples were brought to the laboratory in order to conduct the necessary tests on them.

By using cutting device machine the samples were cut in the form of a rectangular using water to reduce the Friction and ease the cut operation of the samples.

Later required measurements were taken on samples such as the rock weight by using a sensitive electronic balance, measuring the size of each sample, and density.

Ultrasonic testing measurements had been done by using a matest device.

Where we measured the p- wave for each sample length and width Using Vaseline and we measured the s-wave in the same way.

By using the following equations we obtained the elastic dynamic constant

````````````````````````````````````````````

````````````````````````````````````````````````````````````

```````````````````````````````````````````````````````````````

Where

ρ (the density) k (Bulk modulus)

Vp (Compressional waves) λ (Lama constant)

Vs (shear waves) σ (poisson ratio)

G (shear modulus or of modulus of Rigidity)

E (Young’s modulus or modulus of elasticity)

*Measured in terms of each of (G, E, K, λ) unit (Newton / m 2) (N/m2) or Pascal (Pa).

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4-1 Results of physical and dynamics tests:-

Table (1) shows the results of the compressional and shear wave of the samples with the dynamic properties The value of density is between (2.31-3.15) gm/cm3 where The value of poisson ratio is between (0.1-0.4).The value of Vp is between (3563-4265) m/s where The value of Vs is between (1246-2409) m/s.

Table (1) the results of the dynamic properties

Sample no.

Weight gm

Volume cm3

Density gm/cm3 Vp m/s Vs m/s σ

E (Mpa

)

λ (Mpa

)

G (Mpa)

K (Mpa) lithology

1 385 290 2.36 3673 1894 0.3 3187 1838 1225 2655 limestone

2 825 356 2.31 4265 2409 0.26 3442 1479 1365 2390 Calcite

vine

3 511 175 2.92 3658 1246 0.4 1372 2949 479 3266 Marly limestone

4 360 120 3 3563 2393 0.1 3352 380 1523 1396 Marly limestone

5 596 190 3.13 3617 2188 0.2 2881 864 942 1655 Marly limestone

6 990 313 3.15 3881 1742 0.37 1693 1758 617 2170 Marly

limestone

Table (2) the result of the anisotropy calculation

From the Table (2) the samples (1, 2, 5) from the calculation of the compressional and shear wave in different directions they are anisotropy rocks.

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Chapter four

Sample no. (Vp) Anisotropy coefficient1 73.682 85.13

Sample no. (Vs) Anisotropy coefficient2 68.65 71.6

4-2 Statistical mathematical relationships:-

A-Vp and other properties:-

Figure (8) the relation between Vp and E figure (9) the relation between Vp and density

Figure (10) the relation between Vp and lama Figure (11) the relation between Vp and G

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Figure (12) relation between Vp and K figure (13) relation between Vp and poisson

All the relations were in directed proportional.

B- Vs and other properties:-

Figure (14) relation between Vs and G Figure (15) relation between Vs and density

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Figure (16) relation between Vs and poisson figure (17) relation between Vs and E

Figure (18) relation between Vs and K Figure (19) relation between Vs and lama

All the relations were in directed proportional.

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4-2 Conclusions

- The value of density is between (2.31-3.15) gm/cm3.

- The value of Vp is between (3563-4265) m/s.

- The value of Vs is between (1246-2409) m/s.

- The value of poisson ratio is between (0.1-0.4).

- Sample 3 marly limestone has the highest k, ,σ and value and lowest λ value of G, Vs, and E.

- Sample 2 calcite vine has the highest value of Vp and Vs due to the high compressibility of the calcite.

- All the relationship between Vp, Vs and density, E, G, ,λ , K is directed σproportional and has the value between moderate to good.

- The more correlable relations are between Vp and E, Vp and poisson ratio, Vs and E has the value (0.8-0.9) R.

- The moderate relations (Vp and density, Vp and lama, Vp and G, Vp and K, Vs and G, Vs and density, Vs and poisson ratio, Vs and K, Vs and lama) are between (0.4-0.7)R.

- The distribution of the sediments in the rocks causes the anisotropy in some of the samples.

- Sample of (1,2,5) show that there are anisotropy rocks the anisotropy ratio give the value between (68.6-85.13%)

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1- Lama, R.D & Vutukuri, V.S, 1978. Hand book on mechanical properties of rocks.

2- Palmstrom.B.K, 1955, a rock mass characterization system for rock engineering purposes. PhD thesis, Oslo University, Norway, 400 p.

3- Sjogren, B., Ofsthus, A., Sandberg, J., 1979. Seismic classification of rocks mass qualities, Geophysical prospecting.

4- Zhijing wang, M. L. And Nur .A. M.Effect of different pore fluids on seismic velocities in rocks

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Reference