7 Thesis Evaluation

The following science and technology modernization in mining rock mechanics are derived from the original conclusions and content of the thesis with consideration of later work and research:

7.1 Properties of the rock and the bed

The original thesis presented the determination of the fracture toughness of Kallax gabbro and Bjorka marble, and verification of the ISRM suggested standard for rock fracture toughness testing with Chevron notched short rod specimens. The phenomenon of rock cracking and fracture was investigated in details. Besides the application of statistics, the arithmetic of statistical data with a standard deviation was developed and applied. Cracking initiates from the weakest point of the specimen and propagates in the direction that was determined by the specimen geometry and loading condition. Substantial and maximum acoustic emission occurred after the specimen peak load capacity was exceeded, and the post-peak increase is much more pronounced in the tough Kallax gabbro than the Bjorka marble (ref. the cracking sound in pulling the two halves of a bamboo log open, the tearing apart of a softwood stick). This enlighten the weather phenomenon. A strong ecosystem has a high energy storage capacity and shows up as a buffered delay in seasonal change with respect to the earth position around the sun. The two extreme positions occur on June 30 and December 31 of the year. For example, in Ohio state of USA where it is relatively dry, the summer is hot in June, July and August, and winter is cold in January and February. Hot or cold weather are the result of hot or cold energy accumulation from March to August or from December to March respectively. Most of the rain precipitation on the coast of California comes in December and January which is an indication that it is the coolest time period of the year due to the ocean water that does not freeze but transmit heat and wave energy (ocean water at 4 Celsius degrees or more) as well as the great amount of hot water, heating and refrigeration usage at home and work.

The difference between the fracture toughness values of specimens from two Kallax gabbro blocks that looked the same could be attributed to the locations where and times when the blocks were excavated from the ground, the orientation of the cores, and storage time in the basement room of the building, i.e., rock temperature. The fracture toughness of the Kallax gabbro is more than twice that of the Bjorka Marble, but the former has a slightly lower density than the latter (3.1191 versus 3.3666 tonnes per cubic meter). The relative strength of the two rockmass in situ would depend on the rockmass integrity. Because the marble is more deformable, marble deposit is often massive but it may come with bedding planes. Non horizontal foliation planes and fractures are common in hard rocks. They may reflect different in situ stresses.

It should be mentioned that the Chinese people in tradition have used wooden bed with rice hay and cotton linen. Today, many have switched to the metal spring sofa bed. It is realized in year 2010 that the wooden bed has much higher elastic modulus than the sofa bed. Those who grow up on the wooden bed has a higher body density and bone toughness to resist sickness than those who grow up on sofa bed. The latter can not sleep on the wooden bed, and the former would gradually feel the pain of loose muscles and joints in time, age, life style and fitness. As will be shown later, a man has a lot in common with the earth. The fracture mechanics knowledge can guide a person to prevent bone damage during working, walking, physical exercises etc..

7.2 Proof of the classic balance equation method

Appendix 9 presented the calculation of fracture process zone length in the Kallax gabbro with three simplification assumptions. The results are verified in 2009 using a Spreadsheet computer software for numerical "trial and error" approximation with the past results of 1986 as the initial values (ref. Appendix 9B). I could have used the FORTRAN 77 programming language and the mini computer terminal to obtain the accurate solution in 1987, but no one raised doubt about the accuracy of the classic solution. The fracture process zone in the Kallax gabbro rock was determined to be about 10 mm in length in two specimens with ligaments of 0.12 mm and 0.89 mm respectively. This proves that "an expert simplification does lead to the correct conclusion". In fact, the purpose of research is to find natural laws in order to prevent damage. Accuracy is secondary in most cases. Furthermore, such two steps solution method would form part of the learning in science, technology, engineering and law because simple equations are easy to solve and understand, but complex solutions, especially made by machine, may not be understood. The thin section microscopy of the Kallax gabbro specimen 1-7 showed that the fracture process zone consisted of interlocking microcracks and coalescing cracks. The Kallax gabbro is one of the most linear elastic rocks. The fact that it has a non-elastic fracture process zone in tension reminds the people of the fragile crust of the earth. This case shows that the small little problem has an accurate solution (ref. little things add up in time and space). Experience has shown that most big problems are not well defined in extent and time, and have no theoretical and practical solutions (ref. population concentration in cities).

7.3 The mechanical difference between the hard and medium rock

It was also found that the fracture process zone length in the Kallax gabbro specimens equals approximately the theoretical difference between the calculated crack lengths from the secant and the unloading compliances on the complete load - displacement curve immediately after the peak load of the specimen. This provided the indirect method to estimate the fracture process zone length in tough hard rocks. No fracture process zone in the Bjorka marble was observed partly due to the fact that the fluorescent penetrating dye was absorbed by the rock matter and partly due to the fact that less microcracks formed, which manifests in the slight to moderate increase of acoustic emission after the peak load (ref. the deformation of flexible material such as a straw). However, the acoustic emission for the marble may have a lower frequency range and a lower amplitude range that was not detected by the instrument. It should be mentioned that the above theoretical length difference for the Bjorka marble reached 11 to 13 mm. This might be due to a combination of energy loss in the deformation of the arms of the specimen and the plastic deformation zone ahead of the observed crack tip. Such a deformation zone in granite rock was detected by ultrasound probing by Labuz et al. as claimed in a paper (cf. it may be suggested that the medical ultrasound imaging of fetus and the injection of anaesthetic drug during child birth cause significant harm). For the Bjorka marble specimen 3T, the maximum displacement was 385 micrometer (at 12% post peak load), the displacement at the peak load was like the yielding phenomenon over 75 micrometer from 90 to 155 micrometer with more or less constant load. For the Kallax gabbro specimen 2-9, the maximum displacement was 275 micrometer (at 15% post peak load, the disp. can increase with decreasing load), the displacement at the peak load was quite sharp at 95 micrometer. This means that the peak for the Bjorka marble is much wider and smoother than the Kallax gabbro, the former has somewhat more displacement but much less load capacity than the latter. This kind of difference has been found in compression tests of a marble and harder rocks by Wawersik and Fairhurst 1970 (Brady and Brown 1985), the literature showed that hard rocks at higher temperature have more flat load - strain curves). This difference is indicative of the mountain difference between different rock types (ref. the Chinese idiom alt 1 - the stone of another mountain may be used to carve the jade (feed the fish), different mountains from the cold pole regions to the hot equator and on different continents). It is estimated that the cohesion curve of the rock grains and boundaries would be somewhat similar to the load - displacement curve of the specimen. For the marble, the crack tip probably has an invisible and silent yielding zone of pores, but the zone is short and more evenly distributed around the crack tip, that the microcracks that have certain orientation. A few factors may have caused the rocks in the north to be harder than near the equator, such as cold temperature and frozen water molecules, dense electromagnetic field and accumulation of electromagnetic particles over billions of years, less centrifugal force of the earth self rotation or less evaporation.

For the Kallax gabbro, the fracture toughness value is size independent if the specimen diameter is about 51.5 mm or larger, i.e., the specimen ligament length to fracture process zone length ratio is about (1.45-0.82) x 51.5 / 10 = 3.2 or higher. Such a dimension ratio of 3 seems to mark the difference between the intact part and defect part dimensions, such as the grain diameter and the grain boundary material width in a rock. For larger specimens, the fracture toughness non-linearity correction factor is not zero, but, stays at 0.1 to 0.2. It is supposed to be zero for a specimen with linear elasticity. The non-linear property is probably due to the existence of the fracture process zone of about 10 mm. This zone length likely remained about the same with increasing specimen size. Notice further that the Chevron Notch width stayed constant as the specimen diameter and notch length were increased in proportion, such that the crack property at the notch tip was expected not to change as the specimen size was increased. The results for the non-linearity correction factor indicates that this expectation is correct, that is, the non linearity factor value is the highest for the smallest specimen group. Cracks need healing conditions.

As seen from above, with crack propagation, the specimen has less stiffness. This is different from plastic strain hardening of iron and steel, that is, more stiffness with plastic deformation.

The suggested method for fracture toughness testing and calculation procedure included a pretty complex method to obtain the critical load. Two unloading lines need to be obtained before and after the peak load. I did not understand the reason in year 1987. Looking back in year 2013, it would be fine to simply use the peak load, because the error would be nothing compared to the difference between the rock specimens in fracture toughness and initial Young's modulus. The two unloading lines were needed to obtain the non-linearity correction factor, p.

7.4 Prediction and measurement of stability or failure

The Instron loading machine and the two point opening displacement gauge accurately measured the load and displacement which were plotted on paper by an electrical plotting device. The acoustic emission count rate measurement measured the number of peaks exceeding a fixed amplitude in a fixed frequency range. The number depend on the threshold setting and the frequency range. Therefore, it is a comparative parameter, and indicated the maximum cracking rate at post peak load. The complete load - displacement curve from the testing of rock specimen has indicated that in practice, the rock stability beyond the peak load would be uncertain, that is, sudden failure would occur unless the loading system is stiff and servo-controlled. Only minimum or no excavation within the elastic limit of the rockmass can ensure stability. From the scientific and engineering design point of view, all inelastic processes at and beyond the strength are uncertain because firstly there is no unique relation between stress and deformation, secondly a state is not fixed and it changes without giving substantial signal, and thirdly any calculation may not be sufficiently accurate to predict and measure stability, because it is easier to measure failure than stability or improvement. In other words, the inelastic problem has no solution in the eternal time and extent (space). Many inelastic cases may be approximated with piece wise elastic solutions in small steps provided the problem gets better with efforts (ref. mathematical integration).

The philosophy of elastic (talkative, trust worthy, reversible or cyclic, peaceful) progress should always be applied. In society, as in science and technology, theoretical planning and prediction should be carried out first, and a small step positive change may be made to assess the benefit or loss of the change.

7.5 The relation of rock fracture toughness to natural scenery

The years 1984 - 1987 - 2009 led to the discovery of the "YXZT Moment Theory" of "reaction moment of tensile and compressive stresses due to the pulling or pushing action forces". This moment caused acoustic emission and cohesion bond failure at the fracture process zone. The number of acoustic emission per unit time is proportional to the total length of the microcracks. The thin section microscopy of the Kallax gabbro specimen 1-7 showed that the initial two cracks from the notch to merge into a single crack at the initial loop of 9 mm. Theoretical calculation might predict that the initial two cracks go sideways. In Kallax gabbro specimens, the macro-crack deviated somewhat from the central plane, but never went to the side surface of the specimen. In the less strong Bjorka marble specimens, the crack propagated on the center plane in all cases. Based on the difference between the hard Kallax gabbro and the medium Bjorka marble rocks, it can be inferred that the natural river tributary pattern, fault, fracture or foliation pattern at a place is directly related to the rock fracture toughness and rockmass stability. The pattern is generally branched and curved for hard strong rocks, and straight smooth for medium and soft rocks. The are many examples of winding clear gravel rivers in the mountains. In the soft to medium rocks, water seeps into the river bed and banks along the way, such as the great yellow river in northern China. An island in the river, sea or ocean is likely the outstanding hard rock hill. There are less cracks and fractures or they are healed if the river is always submerged in water. This means that the volume of a river space should match the amount of the local rain and snow water resources. According to earth science research, the under water grass, gravel and sand in the river not only prevent leakage but also attract rain or snow with good gravity and moisture, and the trees on river banks or on mountains at a distance away not only store water but also attract and make moisture and rain or snow. On the other hand, artificial straight and smooth channel excavation by blasting and power excavating machine do not reflect the rock property, and it becomes the permanent weak fault zone. Manual excavation in the soft rockmass may shape the river according to design. Manual canals are often piecewise straight. The straight fast water flow does not easily evaporate to rise up, or move sideways, but, the speedy water prevents underwater vegetation growth, and may wash down the bed and the banks. Distributed tributaries with storage pools or ponds are much better than artificially excavated single straight river. The winding canal is better than a straight canal in that it has slow water flow, more water volume storage, more water surface area and more rising evaporation at a certain place. The river with water all the time is better than one with dry and running seasons for the vegetation, fish and the man. The clean water with under water grass absorbs and reflects sunshine and moonlight, let fish prosper, and make gas and water to keep the air warm, but the dark or yellow water absorbs the light to get less and less clear. The river can be a life supporting and ecosystem strengthening path way with soft water and plants, but the dry and hard river or high bank can be a series of permanent fault zone. Obviously, the city of building and pavement, is like a concentrated hard, hot, loose desert or fault zone; high ways, rail roads, flight route are like a series of permanent fault zone of the ecosystem. The dry agriculture land may turn into a semi desert in the fall and winter seasons.

The number of acoustic emission per second is a measure of the gradual damage of the specimen under servo- controlled loading at constant displacement rate, and the recorded amount for the hard Kallax gabbro was 10 times the Bjorka marble. The energy release rate of Kallax gabbro is about twice that of Bjorka marble. It is clear that the natural damage of a rockmass is gradual and dependent on the loading condition, and the final visible destructive rupture does not necessarily have the largest seismic magnitude. Today, earthquakes in the hard rocks, such as the west coast of America, have caught all the attention. But, the loss of snow ice, permafrost land and continental shelves are gradual, distributed and not detected.

Seismic activity is frequent in many a part of the world where the landscape valley, or the pennisula extending from the continent into the ocean, does resemble the specimen with a central notch. For example, at the Baja pennisula at the gulf of California on the USA and Mexico border, seismic location instrument does locate many a seismic source (ref. www.usgs.gov; on the eastern shore of the Pacific Ocean, one may find deep and narrow valley, or sharp barren hill). A sharp mountain peak is subject to wind force. A notch like valley may be subject to seasonal crustal stress concentration that may be compressive, tensile or shear stress. The depth increase of a valley and the growth of a mountain peak are the result of the "mountain movement" in geological history. The thesis does lend certain theory and evidence to the "DIWA Theory" of professor Chen GuoDa of China. Conversely, the application of the "DIWA Theory" does lend evidence of slow fracture and curing or amending process in geomechanics. If a mountain does not have tree cover, then it will lose soil in the wind with the time of day, month and year, and its slope may increase.

7.6 Tension - compression moment in non-symmetric loading

Publications showed that in an uniaxial testing of a hard rock specimen, the visible cracks form first at the specimen surface. The truth of the matter is probably that the center of the specimen is subject to the highest compressive stresses to expand in the lateral direction. Since the ends of the specimen do not move, the middle surface bends, develops tensile stress, and cracks into the open space. Such tension has not been revealed with elastic stress calculations. The hidden damage of tensile stress underground undermines rockmass cohesion and it may be partially blamed on the underestimated rockmass strength. Increasing stresses at cracks or holes cause bifurcating tensile and compressive stresses to initiate damage, although the end result may look compressive (ref. blast holes in a highly stressed stope of ore). The above "YXZT Moment Theory" indicates that a tension - compression moment exists at the fracture process zone in response to the applied non-symmetry tension load. Tensile and compressive stresses or moment exist in rock mechanics, seismology and geotechnical engineering, but it can not be revealed with the elastic continuum mechanics.

7.7 XYZT moment stress reduction philosophy

The years 1984 - 1987 - 2009 led to the discovery of the three "XYZT Moment Stress Reduction Method" to ease the "reaction tensile and compressive stress moment due to action forces at a distance". This author did use a group of mathematics equation and wisdom to ignore insignificant term to achieve solution. Firstly, increase the unifying cohesion bond and support to resist the loads; secondly, maintain material unity, permit load distribution, movement, rotation, harmless friction, and energy transformation to reduce stresses; and thirdly, reduce, remove or depart from applied forces or shorten the distance from the weak joint to the point of loading. It is noticed that the ancient negative military warfare "Sun Zi Bing Fa - 36 military tactics" listed alt 2 as the upper (noble, let) tactics. This means that the 36 military tactics are negative tactics or collective suicide tactics except for the alt 3 (to go towards the noble or return is the upper tactics).

7.8 Rock and mineral veins like the tree leaves and branches

In year 2009, it was rediscovered that the English word "Rock" in Chinese PinYin means alt 4 (has it to rely on, must think and quiz, firm to protect the water buffalo). Rocks and minerals are the most stable and rare matter in the universe. The true rock strength is the cohesion strength to maintain its comprehensive functions in the earth. Cohesion gives to elasticity and tensile strength, as well as shear and compressive strength. Only elastic material can bear and transfer a limited load in the long run. Cracked rocks can not heal in ten thousand years of time or not at all if the climate worsens. On the other hand, cracks can remain closed and tight under water or oil. The cracked rockmass as a physical system has many mechanical, electromagnetic, heat and water properties. The commonly used friction strength is a transient lock up and energy consumption strength. Water atoms are important parts of the intact and fractured rock. Minerals are part of the water, rain, snow and cloud. The laboratory experiment showed clearly that artificial low viscosity liquid penetrated the rocks with microcracks. This shows how liquid could seep or seal the cracks of the earth. The earth's crust or surface with the mineral veins is like the leaves and branches of a tree. The research results may be applied to respect, preserve and cultivate the dear earth and the man.

The use of an epoxy to repair a dented cracked windshield was probably inspired by the above discovery of the fracture process zone (ref. in year 2004 AMICA Insurance Company contracted a specialist company to repair a dent on the windshield and offered life time guarantee). The steel fibre reinforced shotcrete material was likely inspired of the fracture process zone idea. It should be reminded that the capital urbanized way of life with automatic water, excrement discharge and electrical machines consume infinite amount of energy and resources as compared to the manual and mental agriculture that contribute to the earth and the people. The city gets much worse with office works, commuter transportation systems or automobiles in addition to the automatic water, electricity and sewage.

7.9 Rock intelligence and elastic modulus

The rock specimens cracked in consistent patterns in response to the tensile load applied by the stiff and servo-controlled material testing machine. It was realized in 2008-2009 that the specimen response was similar to the semi-conductor digital computer (ref. computer program simulation of simple system response in the author's 1993 thesis book) . The rock specimen responded to applied load in an accurate computational manner. The Chevron notched short rod rock specimen for fracture toughness testing is like the modern quartz clock that counts the vibration of a notched quartz crystal with battery electricity. The clock system functions only if all components are elastic.

The thesis showed that the fracture toughness increases with elastic modulus for the two types of rocks. From energy point of view, the material compressive strength is a function of elastic modulus and deformability, which depend on cohesion and friction found in the Mohr - Coulumb Strength criterion. By comparing the elastic modulus and strength values of different materials, it is found that there is an approximate trend that the strength increases with elastic modulus. This is good news because the elastic modulus can be measured with many elastic methods, i.e., non destructive methods, such as stress wave (see proof in the author's 1993 thesis) and ultrasonic wave (see author's 1991 report). It has been proven that the elastic modulus from wave propagation speed is very stable due to small stress or strain change. Therefore, the elastic modulus can be used as a predictive parameter for material capacity with material preservation. This agrees with the Chinese proverb alt 5 (the good beginning is half the success). For example, by knocking on a body of material and hear the sound, one can estimate the stiffness of the system. In comparison with duty work and physical education, only pseudo-elastic stress or strain training may improve the modulus and strength.

An aluminium model specimen was tested to obtain the Young's modulus in order to check and calibrate the testing machine. The aluminium fracture toughness from the literature is about 10 times the Bjorka marble, it is one of the softest metals with excellent deformability. The elastic modulus calculated from the testing curves of the short rod rock specimens were quite variable. This is probably because (i) the INSTRON testing machine did not measure the minimum load accurately, (ii) the displacement strain gauge did not measure the minimum strain accurately, (iii) compliance of the Chevron notched short rod specimen is not stable due to crack tip position accuracy change, (iv) compliance of the Chevron notched short rod specimen is quite variable due to crack propagation at minimum tensile load, that is, the Young's modulus of rock under tensile stress is not stable due to being formed under compressive stresses in geological history. The stress wave or ultrasound causes very little stress or strain change. Experience in underground mineral excavation did indicate that in situ rockmass has zero tensile strength and a small percentage of compressive strength. This is really due to the elastic modulus variability with tensile stress and near zero stress.

Although the measurement unit of the fracture toughness parameter looks odd, it is a tensile strength criterion that reflects cohesion . The modulus measures the dual elastic properties of stress and strain. In view of the dual properties of elastic modulus and deformability, the different rocks are more alike than different. For example, the Kallax gabbro has higher fracture toughness but lower deformability than the Bjorka marble, and if the latter is compressed in the ground for a long period of time, it would become tougher but less deformable. Metals have high strength and deformability but do not last as long as the rock, and the cost is more than the gain. It is a shame to use metals for destructive goals to cause much more loss than the cost. The energy release rate parameter is easier to understand, and for the mode I pulling forces in plane stress conditions, it is calculated with the formula, G = K²/E, where K is the fracture toughness and E the elastic modulus. It was about 51.2 J/m² for the Bjorka marble, and from 85.4 to 124.9 J/m² for 4 different specimen groups of Kallax gabbro. Although the energy parameter is a combination of force and displacement parameters for the mechanical property, either force or displacement has different effect on other physical properties of the material. It should be mentioned that the average energy consumption per unit fractured area for the complete force displacement curves for the triangle specimen area for the Bjorka marble 3T and Kallax gabbro 2-9 were 94.21 and 168 J/m² respectively. Although the values are higher than above, the ratio is about the same. Hence, the average energy consumption per unit fractured area is comparable to the fracture toughness parameter. It is much easier to calculate. The energy storage or consumption is a measure of stress and strain, or strength of the material.

The fracture mechanics energy release rate cautions one to watch for the dead load or increasing load conditions, such as the weight of things, or the water rushing through a leakage hole. Under dead load conditions, a perfect or cracked body has the tendency to rupture once fracture initiates. There is no warning for remedy. In order to prevent rupture, the load must be prevented, avoided, reduced or removed. The energy release rate is actually the self-destructive energy consumption rate, that is, the stored energy is consumed in the self destruction process. At the present time, some industries and societies create and consume vast amount of artificial energy at the expense of the earthly and natural matter and energy. Nearly all machine energy are transferred from the earthly and nature matter and energy into the the destruction of the man, earth and nature. Even the house machinery, food and energy intake in the industrialized countries have increasing and relentless power to damage and destroy the man and earth nature. It is time to uphold and spread justice rights, correct mistaken error.

The eternal earth clock is worthy of respect, preservation and cultivation. It should be born in mind that computer technology was developed to help people understand the intelligence of things such as rock, ecosystem and the earth. Computer system components were designed to imitate the mental intelligence to a certain extent, which in turn also helps some understand the mental intelligence. The computer was originally intended as a device for programming research. The computer artificial intelligence, i.e., the "Ai" technology, might have been chosen to appreciate the "dear earth" with the Chinese character "Ai" ( alt 6 love).

Despite different forms of natural intelligence, the intelligence and power of the surname man can be used for good purposes without harming the earth nature. The thesis writing shows the intelligence of searching the literature for what is relevant, comparison, experiment to find the missing truths, equation formulation, wise simplification and solution for variables, discussion, conclusion. Appendix 9B presents the computer spreadsheet digital solution for the Appendix 9 equations without simplification, the result was within the tolerance of the previous solution, that is, the computer power confirmed the author intelligence and conscience. In history, the earth nature has suffered a great deal from machines, structures, chemicals etc. made from materials or ore excavated from inside the earth by big organizations. The motor electric machines were originally intended as devices to learn about the movement and intelligence of the earth, the moon and the solar system, but, they have been misused as commodity for consumption and as damaging production power. The electrification, drainage and pollution of the river is clearly against the "free river" English - Chinese pronunciation characters alt 7 . In half a century, the research computer device has been promoted by some as production machines to compete with man in intelligence and power. Little did they know that the power machinery got the supportive work of intellectuals who were supported by manual peasants, workers, fisherman, hunters etc.. But, the organizations and machinery acted as dead or increasing load to damage the man and the earth nature. The process is called alt 8 (to shift crisis). Likewise, computerized machinery, organization and man depend on minerals exploited from inside the earth and a lot of energy resource of the earth for additional work, and they would need greater and greater support of manual peasants and workers etc.. The man, and even the earth, would lose everything and longevity quickly without the chance to return. Hence, the man must fully use his or her manual and intellectual power, in order that the ecosystem will be supportive, and the earth and the moon will fully use their power to move in the solar system.

In 1980, the author took a course on Basic programming on Apple computer. There was very limited laboratory time to test the exercise code. In 1983, the author obtained tickets to try the main frame computer at the computer center, but never saw the computer. During the postgraduate studies and research in Sweden from 1984 to 1987, the author took a course on FORTRAN 77 programming, had some time to test the codes on the mini computer terminals, used the terminal to enter the research thesis book in English. From year 1989 to 1993 in Canada, the author used Turbo C/C++ to program a number of computation and graphics programs. In year 1994, he took a fourth year computer artificial intelligence course. Based on the method in the book, the author programmed the Hexxagon Checker game as the course project with Turbo C/C++. From year 1996 to 2000, the author used the Microsoft Visual C/C++ and AutoCAD 13 to 14 with the C/ADS-ARX API to program the RocCAD mining software product that were marketed to three mineral companies. The human friendly ASCII text input and output used to be the standard computer "IO" until Windows 95. No real progress has been made in computer science and technology since then with regard to its research purpose. The computer is a research investment at a cost much greater than the price. All software must be programmed to input and output ASCII text file format, including multimedia software, such as the sound recorder. To keep track of the history and technology of computer, all computer models and software should be maintained and repaired.

In the Bible book of Genesis, there was a story about Eve who took an apple from the apple tree in the center of the Garden of Eden against GOD's forbidden word. The story was probably a real story to preserve the fruits of the center apple tree in its natural state, and to preserve seeds for the trees. It applies to many things because seeds change with the climate, soil, and fertilizer etc.. If the good things are all consumed, wasted or lost, there would be no way to get them back, there would be increasing suffering and less longevity.

7.10 Respect for the comprehensive agriculture and the earth nature

It should be mentioned that the so called "tectonic plate boundaries" of the earth crust are probably the fracture process zones of the earth's thin crust, so are the earthquake faults. These boundaries react quickly to the deformation of the whole earth during the solar system navigation in the forms of tidal and seismic waves, earthquakes, lava flow and volcanoes (ref. Islands in the north and south Pacific ocean, vocano mountains on the west coast of America). The thesis calls to attention the stability problems at the ocean bay cantilever arms of the continents. The shape of the central and south America continent would indicate that the thin central American ridge has probably yielded. Effort should be made to preserve the land link between the South and North America.

The cracking and fracturing of rocks involves a certain loss of cohesion and matter. It takes certain energy and matter to cement together the fractured rocks. Unlike the burning, explosion or fission of things that release heat, shockwave and electro-magnetic energy, the claim that fusion of hydrogen atoms into heavier atoms would release nuclear energy is likely false . In other words, the destruction of matter such as burning and nuclear fission under high temperature can be fast, but the fusion of atoms and particles into matters such as rocks, minerals, water and food needs energy and time (ref. plant growth, light matter may be compressed into higher density). The fusion of oxygen, hydrogen, nitrogen, and fine particles etc. into rain in lightning and thunder needs energy such as sunshine and gravitational electro-magnetic energy. Good work and rest conditions, food, rest and sleep would guarantee good health and happiness. Research and production works that harm the earth and the person in irreversible fashion must stop. The real contradictions to be resolved today are firstly that of life and death and secondly that of the right comprehensive agriculture with nature and the wrong concentrated city and industry. While the collapse of the comprehensive agriculture may look easy and release out some energy, the process is nearly irreversible.

The Mao ZeDong contradiction theory was meant to resolve existing contradictions. On the contrary, to make contradiction is to make trouble, it is a failure process. A learned and experienced person can increase comprehensive knowledge, wisdom, ability and sensitivity by hundreds and even infinite times. The Chinese people had the best and most stable jobs and living conditions in the world thanks to the comprehensive agriculture with nature till the 1980's and even today. People must resolve their difference peacefully to help with the unity of the dear earth.

It should be mentioned that the process of giving birth has certain similarities with the extreme loading or fracture of intact materials. The damage of the pavement by the de-icing salts is an example of how the earth surface is being damaged and polluted by industry and mechanized agriculture.

7.11 The empirical comparison method

The above data showed that regardless the representative parameters, the difference between the Kallax gabbro and Bjorka marble was undoubtedly distinguished. At the present time, all engineering disciplines use the empirical methods to find the best solution by employing the so called "search intelligence" to compare advantages and disadvantages (ref. the computer international chess game). Industry engineering or any other collective works on and inside the earth and the empirical methods have lacked theoretical solution and practical proof, and the work processes are non-elastic or irreversible consumption of energy. In other words, the game changes with energy input and time.

In terms of current mining engineering, the absolute strength numbers for different rock types are less important than their relative strength. In manual stress calculations or computer modelling with numerical methods, the rock mass strength may be a certain fraction of the intact rock strength as a function of geomechanics mapping and field failure observations and calibration. As can be seen, to excavate and grind the mineral rock into fine powder of particles less than the grains in order to gain the precious metal elements and temper them into money or machine is irreversible destruction against the geological history of the earth and the astronomical time of space.

Regardless the current practice, the goal of reform in the comprehensive agriculture, engineering, medicine, etc. is to improve the benefit of people and earth nature with no damage or destruction, or at minimum damage less than the natural growth, as described by the two words "ministry, ministration". For practical purpose, the comparative difference between things or life forms matter more than the absolute number result from analysis with conventional static theories and laws, particularly for the timely cumulative process of gain or damage. All the reform works have so far fallen short of, or gone astray from, the above goal. On the contrary, the money goal chains have driven people to destroy more surname man and earth nature for more money.

So far, empirical engineering work has been one of linear extrapolation of Newton's laws of physics, or simply chemical trial and error. This is very much like the solution of simultaneous equations or the input and output of the simple computer neural networks. The ancient Chinese book of "Yi Jing - Zhou Yi" marked the realization of "Zhou Yi" or cyclic change in the China Zhou dynasty of about year 1100BC. Having realized the cyclic movement of the earth daily self-rotation, monthly cyclic movement with the moon, yearly cyclic movement around the sun, the man should always think of "go return" cycles to do good pseudo-elastic work. The uniform circular movement is a good physics model to correctly apply the Newton's laws.

In terms of rock fracture mechanics, the average energy consumption per unit fractured area for a specimen of sufficient dimension under a certain strain rate is much easier to obtain and to understand for comparison purposes than the fracture toughness calculation procedure. The energy input and output method is the best method to analyze questions from small to big, and from static to dynamic, especially large scale system questions.

The rock mechanics literature has lots of evidence to show that the larger the rockmass, the less its compressive and tensile strength. There are many formulas to relate the in situ pillar strength to shape width to height ration and volume. The author's thesis proved that the fracture toughness remains constant for different diameters and lengths of similar specimens, i.e., it does not change with volume. This means that it is not the volume of the rock material but the bedding or foliation planes, cracks, fractures and faults that reduce the rock strength. In other words, every rockmass is different and is characterized by the rock material and the planes of bedding, foliation or contact, cracks, fractures and faults. In engineering, the rockmass changes with energy input and time. Because the ore zone usually has distinct contact with country rockmass, i.e., it is usually a fault zone, shear stress and displacement of the ore zone is inevitable with extraction. The fracture mechanics test with the Bjorka marble

As discussed above, the Short Rod specimen testing of the Bjorka marble specimen 3T showed extraordinary yielding displacement. On page 45 of the thesis, there was a footnote that on 3T, a weakness plane intersects the notch plane at an angle of 30 degrees. It was unknown if this weakness plane contributed to the yielding displacement. But, the proportaional fracture toughness and energy consumption calculated above indicates that the weak plane was not mobilized. Shear displacement on weakness features is usually many times more than the overall tension or compression displacement.

In underground engineering, the empirical method to first fix the in situ stress field on the basis of the gravity stress, and then downgrade the rockmass strength to a fraction of the intact rock strength to fit failure observation, is of course empirical. In terms of science, the earth gravity has so far been taken as constant for granted. Since the earth rotates and travels at great speed in comparison to the speed of sound, the earth bears great dynamic stresses that change daily, monthly and yearly. The vertical gravity that the earth relies on for life is on the balance with lateral dynamic stresses. Instead of the lateral stresses being a fraction of the gravity stresses, the vertical stresses may change significantly with the lateral stresses in the earth's crust. Hence, the rock strength is relatively stable and known, but the in situ stresses are changing and unknown. The earth surface rockmass changes with geological time. Under the original earth nature, the rockmass grow very slowly, but, under current conditions when the earth's interior and surface are exploited for material and energy, the thin crustal rockmass lose strength in proportion to artificial energy production and usage.

The surest thing to walk to justice rights is the alt 9 , i.e., the right "surname man tribe genealogy (generations poem, family genealogy)". It is the surest solution for happy longevity on the eternal earth. It has been proven by Chinese practice and science.

7.12 Mini model for mining method design

From the energy balance and rock mechanics point of view, the less the extraction rate the safer it is to work underground. From the earth health and healing points of view, the less the excavation into the ground the better. Of course, it is better to never work underground. From the ground support point of view, renewable wood and bamboo materials offer the cheapest and the safest mechanical support, except that the fire hazard should be strictly prevented. The early excavation method of room and pillar shrinkage stope with backfill are the best mining methods. The English word "stope" has the "stop" sign which is the first priority. In the modern time, the cost of motorized mechines and the overall costs of industry from the organization, education, excavation, manufacturing, transportation, supply, ministry to money etc. have demanded the large scale, full time, quick and full excavation of the deposit. The loss and dilution of the ore are measured in percentages. Mineral veins are permanently depleted without a chance to grow. Hence, the early mining methods were better for the earth and the people, and more importantly, the cultivation and preservation meaning of the word "mining" must take precedence over the making of tools for the comprehensive agriculture.

The Chevron notched short rod fracture toughness specimen in a way models the underground mined out ore zone, except that the underground compressive stress is modelled with tensile stress in the experiment. Compression and tension moment should exist at the bottom of the mined out ore zone, or at the top rock if there exists a rockmass cap on the ore zone. Therefore, at the bottom or top of the mined out ore zone, it is likely the tensile cracking that causes cracks to increase with time. Tensile stress in certain orientation would occur at certain places of the opening, and tensile cracking would occur to reduce the tensile strength of the rockmass to zero, to be followed by compressive, shear failure and gravity fall, such as in the hanging wall of the mined out ore zone. Dynamic stresses from blasting and drilling are both compressive and tensile to increase tensile cracks and fractures. This explains in part the rockburst or earthquake around the mined out underground space of the past.

7.13 Joining together of fractured rock

The discovery of the fracture process zone has made it clear to use suitable support element or system to keep fractured rock in place in order to maintain stability. On the other hand, taking away fractured rock would cause more fracturing. In the crack propagation experiment, an epoxy ( alt 10 ) or resin gel was injected into the rock specimen notch to stabilize its status in order to cut the specimen into slices and measure the crack length on each slice. The epoxy hardened and kept the two halves of the specimen together. It was a successful method to join the fractured rock pieces together. However, the strength of the rock to epoxy adhesion bond was not tested or measured. The joint strength should be the lowest of the three: the hardened epoxy, the epoxy bond to rock surface and the rock material. Many current rock support materials depend on its adhesion bond with the rock in the drill hole or on the tunnel surface.

The fracture process zone properties would help one to appreciate the earth surface to shield the earth with plant leaves and roots, soil and rock, e.g., the bamboo tree grow fast and cover the ground with thick leaves and a network of roots. The soft surface rocks such as the limestone prevents deeper hard rocks from cracking and corrosion etc.. The original earth surface can grow very slowly.

As seen, the meaning of the word "joint" includes the "bedding plane, foliation plane, weak plane, fracture" ( alt 11 ).

7.14 Comment on the manual typewriter

Professor Lai gave the author a Chinese booklet on practising English typing in 1983 in preparation to go abroad. The author used it to practise typing the thesis into the mini-computer terminal. The year 1987 thesis book was printed from the mini-computer printer. The quality was comparable with the electric typewriter. About a hundred copies were made to bind into soft cover books by the university printing shop. When returning to China in year 1987, the author ordered in advance a simple portable English manual typewriter at the Foreign Currency Store in Beijing at about USD$50 as a gift to the dispatching department in Changsha to type letters. The function of the typewriter is open and clearly visible, like dymamic stamping with permanent ink tape. It turned out that the printed letters appeared blurred on the copy machine paper. It was a disappointment that the light typewriter did not work properly. The author gave it to the department library as an exhibition and for typing practice. The other television and cassette radio devices bought from the store worked fine.

In 1993 when preparing the thesis book for hard cover binding in Canada according to thesis requirement, the author found in the store that there were many different types of paper with different densities. In retrospect, the manual typewriter of 1987 gave too much impact on the copy machine paper to cause the ink to seep into the cracks of the paper. It was like a dynamic fracture mechanics experiment. Just as the marble rock in the thesis was permeable but gabbro rock was not, a different type of paper with different permeability and cushion properties, or a different ink tape for that matter, would have eliminated the problem. In year 2013, the author would like to guess that the white copy paper used in England or Sweden is possibly different from the white copy paper in China. Anyhow, it is good for practising alphabet or PinYin typing, as exhibition in a library, laboratory or museum. A further point to make is that hand writing letters and form filling are acceptable in all countries of the world. In year 1986, the author translated the rock mechanics course material into a Chinese book with the core pencil hand writing on copy machine paper, with the aid of a rubber eraser for correction. Copies were made to bind into books that were distributed to the international mining workshop participants. Meeting, conference, newspaper, journal, book publications, policy document, business papers, etc. should admit hand writing articles.