1. Introduction CONSTRUCTION HANDBOOK ROCK EXCAVATION HANDBOOK .. 2 3 ROCKEXCAVATION HANDBOOK PREFACE The construction business is continuing to grow at a fast pace worldwide. The construction business is closely related to the world economy as well building of infrastructure. The building volume is increasing even though there are big regional variations. Interesting part of construction is rock excavation and the big variation of rock properties is challenging everybody involved; contractors, consultants, equipment suppliers etc. At the same time development of technology is offering new methods and solutions for surface and underground applications. Sandvik Tamrock has published this handbook to present these applications as well basic information to assist selection. Thus this handbook will serve anyone who deals with the construction exca- vation business. It is also good reference tool for those studying related subjects. Several people participated in writing this book and therefore I like to extend my thanks to Unto Ahtola, Karlheinz Gehring, Pekka Kesseli, Peter Kogler, Pasi Latva-Pukkila, Arne Lislerud, Maunu Mänttäri, Jukka Naapuri and Tuomo Niskanen. Special thanks to Kirsi Nieminen, Nordberg Inc, Aimo Vuento and his students at South Carelia Polytechnic, Raimo Vuolio, Finnrock Inc and Pekka Särkkä, Helsinki University of Technology. Finally I like to thank Leena K. Vanhatalo collecting and editing this handbook. Matti Heiniö Editor in chief 99-808-GB-6000 © Copyright Sandvik Tamrock Corp. 1999 Any diagramm, picture schematic or other matter contained herein is provided for illustrative purposes only. Accordingly, any matter set forth herein schould not be exclusively relied upon by the reader. .. 4 5 ROCKEXCAVATION HANDBOOK TABLE OF CONTENT 1. INTRODUCTION.............................................................................10 2. MATERIAL PROPERTIES 2.1 GEOLOGICAL CLASSIFICATION OF ROCKS...................................12 2.2 MECHANICAL PROPERTIES AND ROCK BEHAVIOUR....................19 2.3 RATING ROCK MASS CUTTABILITY AND DRILLABILITY..............20 2.4 ROCK ABRASIVITY – TOOL SERVICE LIFE...................................30 2.5 ROCK MASS CHARACTERIZATION.................................................46 2.5.1 Importance.............................................................................46 2.5.2 Interbedding...........................................................................46 2.5.3 Rock mass discontinuities.........................................................47 2.5.4 Classification of rock mass properties........................................48 2.5.5 Rock pressure..........................................................................52 2.6 BENCH BLASTING OPERATIONS...................................................53 2.7 CRUSHABILITY..............................................................................57 2.8 CONCRETE.....................................................................................60 .. 6 7 ROCKEXCAVATION HANDBOOK 3. PRINCIPLES OF ROCK EXCAVATION TECHNOLOGIES 4.2.1 Drilling and Blasting..............................................................142 4.2.2 Primary Breaking by Hydraulic Hammer...................................183 3.1 MECHANICS OF ROCK BREAKING.................................................62 4.3 QUARRY CASE.............................................................................187 3.2 TOP-HAMMER DRILLING...............................................................63 3.3 PRINCIPLE OF DTH DRILLING.............................................71 5. GENERAL CONTRACTING 3.4 ROTARY PERCUSSIVE DRILLING .........................................71 5.1 GENERAL.....................................................................................188 3.5 HYDRAULIC HAMMERS......................................................71 5.2 METHODS....................................................................................189 5.2.1 Drill and Blast Excavation......................................................189 3.6 CUTTER-CRUSHERS AND PULVERIZERS.......................................73 5.2.2 Demolition and Recycling.......................................................204 3.7 CUTTING.......................................................................................74 5.3 CASES..........................................................................................211 3.8 LOADING AND HAULING..............................................................76 5.3.1 Highway and Railway Cutting.................................................211 5.3.2 Demolition and Recycling.......................................................213 3.9 CRUSHING OPERATIONS...............................................................82 3.10ROCK BLASTING...........................................................................93 6. TUNNELLING 3.10.1 Blasting products..................................................................93 6.1 GENERAL.....................................................................................214 3.10.2 Rock blasting theory............................................................120 3.10.3 Blasting and environment.....................................................123 6.2 METHODS....................................................................................216 6.2.1 Drilling and blasting..............................................................216 4. QUARRYING.............................................................................. 6.2.2 Mechanical tunneling.............................................................254 6.2.3 Shaft Excavation...................................................................281 4.1 GENERAL.....................................................................................140 6.2.4 Rock reinforcement................................................................290 4.2 METHODS....................................................................................142 .. 8 9 ROCKEXCAVATION HANDBOOK 6.3 CASES..........................................................................................299 8. WATER WELL DRILLING 6.3.1 Railway tunnel......................................................................299 6.3.2 Oil and gas storage................................................................300 8.1 GENERAL.....................................................................................324 6.3.3 Hydropower stations and waterworks.......................................301 8.2 METHODS....................................................................................325 6.3.4 Hammer tunneling.................................................................302 6.3.5 Roadheader tunneling............................................................303 8.3 WELL DRILLING PROCESS..........................................................336 7. DIMENSIONAL STONE QUARRYING 9. EXPLORATION DRILLING 7.1 BUILDING STONE MATERIAL......................................................306 9.1 GENERAL.....................................................................................340 7.2 METHODS OF ROCK EXTRACTION...............................................308 9.2 METHODS....................................................................................340 7.2.1 General.................................................................................308 7.2.2 Extraction and Cutting of Hard Rock........................................309 10. PROJECT PLANNING AND IMPLEMENTATION 7.3 QUARRY PLANNING....................................................................315 10.1PROJECT COSTS..........................................................................344 7.4 FINANCIAL RESULT OF QUARRYING..........................................317 10.2TAMROCK PROJECT STUDIES......................................................347 7.4.1 Costs....................................................................................317 10.2.1 Excavation Process recommendations.....................................347 7.4.2 Methods of succesful quarrying ..............................................320 10.2.2 Equipment selection.............................................................347 10.2.3 Performance and cost studies................................................348 7.5 FOUNDING A QUARRY................................................................320 10.3SERVICE SUPPORT......................................................................354 7.6 DRILLING TOOLS SELECTION FOR DIMENSIONAL STONE INDUSTRY.......................................................................321 REFERENSIS ........................................................................................364 .. 10 11 ROCKEXCAVATION HANDBOOK 1. INTRODUCTION Excavation activities at construction sites are very diverse. Contracting customers also vary significantly in size. What is a typical construction project made up of? The answer is that all construction projects are time-limited. Project duration varies from one month to several years, and the schedules are almost always tight. Usually, immediate mobilization takes place once the contract has been awarded and often there are penalties involved if the original schedule does not keep. It is therefore important to choose the right excavation method together with the right equipment to keep the project on schedule. This handbook covers all modern excavation methods and also provides some recent case stories. Excavation methods can be divided into groups. The following classification shows how it is handled in this book. Both aggregate and limestone quarrying by the drill & blast method and mechanical method is discussed in the chapter called “Quarrying”. General contracting includes a wide range of projects from rock foundation in buildings and roads to channel excavation in dams, road cuttings etc. Underwater excavation is also includ- ed in this section. Today, demolition and recycling play an important role and are discussed in detail in the chapter on general contracting. In the “Tunneling” chapter, which also includes underground excavation, both traditional drill & blast and mechanical method are discussed. Underground excavation varies significantly from sewage tunnels and powerhouses to railway and highway tunnels as well as from ware- houses and parking halls to theaters, swimming pools and ice-hockey halls. Dimensional stone quarrying is explained according to each method in use. The last chapter concerning excavation methods describes water well and exploration drilling. The final chapter is dedicated to project management. It describes issues that should be con- sidered and remembered when handling an excavation project. Last but definitely not least is service support. At the end of every chapter, there is a case description providing a real-life example of a typical excavation site. .. 2. Material Properties 12 13 ROCK EXCAVATION HANDBOOK 2.1 GEOLOGICAL CLASSIFICATION OF ROCKS Geological and mechanical properties of rock are interrelated; both must be taken into account when planning rock excavation, from designing underground openings and quarries to estimating drilling and blasting performance. Rock characteristics are determined primarily by origin, formation and mineral composition (FIGURE2.1.-1). Geologically speaking, the earth is in a state of flux where both rocks and minerals are con- stantly being formed and altered (FIGURE2.1.-2). It is convenient to divide the rocks in the earth´s crust into three categories based on origin: igneous, sedimentary and metamorphic rocks. FIGURE 2.1.-2.Geological cycle. The way in which the composition of the earth´s crust is dominated by eight elements is pre- sented in Table 2.1.-1.These elements, together with some others elements, form twelve common minerals which comprise approximately 99% of the earth´s crust. The remainder of the over 1,000 known rock-forming minerals make up less than 1% of the earth´s crust. Table 2.1.-1. Major chemical elements in the earth´s crust. FIGURE 2.1.-1.Formation of minerals and rocks. Chemical Elements Weight Percent (%) Volume Percent (%) Oxygen ( O ) 46.40 94.04 MINERALS Silicon ( Si ) 28.15 0.88 All rocks consist of an aggregate of mineral particles. The proportion of each mineral in the Aluminum ( Al ) 8.23 0.48 rock, together with the rock’s granular structure, texture and origin serves as a basis for Iron ( Fe ) 5.63 0.49 geological classification. Calcium ( Ca ) 4.15 1.18 Sodium ( Na ) 2.36 1.11 A mineral may be defined as an inorganic substance that has consistent physical properties Potassium ( K ) 2.09 1.49 and a fixed chemical composition. With the exception of some carbon forms, sulfur and a few Magnesium ( Mg ) 2.33 0.33 metals,all minerals are chemical compounds each containing two or more elements in fixed proportion by weight. Some elements are present in many minerals, the most common being It can be assumed, therefore, that most, if not all, rocks encountered in mining and civil oxygen and silicon, while others, including most precious and base metals, form an insignifi- engineering consist of two or more minerals, each with its own particular set of physical cant proportion of the rocks within the earth´s crust. properties that can affect the rock’s engineering properties, such as the preferred cleavage 2. Material Properties 14 15 ROCK EXCAVATION HANDBOOK direction and fracture. Hardness and crystal structure used to define minerals can, in some considerably in chemical stability. Susceptibility to chemical attack of common rock-forming situations, determine the rock’s reaction to outside forces, particularly where large amounts minerals can be ranked as follows: olivine, augite and calcium feldspar of a relatively soft mineral with marked fracture properties, such as mica or calcite, or of a > hornblende, biotite and sodium feldspar particularly hard mineral such as quartz, are present. > potassium feldspar > muscovite > quartz. Quartz is the only common mineral in igneous rocks that is highly resistant to weathering ROCKS processes. All minerals tend to be altered when attacked by oxygen, carbonic acid, and water; forming new minerals that are more stable under the new conditions. The altered rock Magma is essentially a hot silicate melt (600-1,200°C), and is the parent material of igneous crumbles under the mechanical effects of erosion and is transported by wind, water, or ice rocks. Magmas and the formation of igneous rocks can be observed in volcanic regions. and redeposited as sediments or remain in solution. Usually, magma solidifies within the crust, and the formed rocks are later exposed at the sur- face due to erosion or earth movements - hence their classification as plutonic (intrusive), Sedimentary rocks can be subdivided into three main groups according to whether they were hypabyssal or volcanic (extrusive), depending on the depth and rate of cooling, which affects mechanically formed, formed from organic remains or chemically deposited. (Table 2.1.-3.) texture and crystal size. Table 2.1.-3. Geological classification of the most common sedimentary rocks. Igneous rocks are also subdivided by composition into acidic, intermediate, basic (mafic) and ultrabasic (ultramafic) rocks depending on the amount of silica in the composition as pre- Method of Classification Rock Type Description Principal Mineral sented in Table 2.1.-2.A relatively high hardness as to mineral constituents in igneous rock Constituents can immediately be seen. Mica content tends to be small. Formation MECHANICAL Rudaceous Conglomerate Large grains Various in clay matrix Table 2.1.-2. Geological classification of the most common igneous rocks. Arenaceous Sandstone Medium round grains Quartz, Feldspar, Mica, in siliceous, calcareous Calcite Texture Acidic Intermediate Basic Ultrabasic or clay matrix > 66% silica 66 - 52% silica < 52% silica < 45% Breccia Coarse angular grains silica in matrix Argillaceous Clay Micro-fine grained Kaolinite, Quartz, Mica PLUTONIC Granite Syenite Diorite Gabbro Peridotite - plastic structure (coarse grained) Dunite Shale Harder - laminated Pyroxenite compacted clay HYPABYSSAL Micro- Micro- Micro-Diorite Diabase ORGANIC Calcareous (siliceous, Limestone Fossiliferous, coarse Calcite Granite Syenite ferruginous, phosphatic) or fine grained Carbonaceous Coal VOLCANIC Rhyolite Trachyte Andesite Basalt (fine grained) CHEMICAL Ferruginous Ironstone Impregnated limestone Calcite, Iron Oxide or clay (or precipitated) Principal Mineral Quartz Orthoclase Plagioclase Augite Augite Calcareous Dolomitic Precipitated or replaced Dolomite, Calcite Constituents Orthoclase Plagioclase Hornblende Plagioclase Olivine (siliceous, saline) Limestone limestone, fine grained (Mica) (Mica) In engineering, the most important sedimentary rocks are arenaceous (sand), argillaceous (clay) and calcareous (limestone) rocks. Typical arenaceousrock consist of discrete fragments of minerals,such as quartz and feldspars, held together by a matrix of clay, calcite or hydrothermal quartz. Thus, when a sandstone is broken, fractures follow the weaker clay or Sedimentation is the result of atmospheric and hydrospheric interaction on the earth’s crust. calcareous cement rather than propagating across the stronger grains. An argillaceous rock The original composition of the crust, igneous rock minerals, are more or less readily such as shale consists of minute particles held weakly together and comprising largely of attacked by air and water. Having been formed at high temperatures, and occasionally high kaolinite. Calcareous rocks consist of organic remains, or precipitates, mainly in the form of pressures, they do not remain stable under significantly varying conditions. Silicates vary calcite. 2. Material Properties 16 17 ROCK EXCAVATION HANDBOOK Metamorphism is defined as the result of the processes that, beyond weathering, causes the Table 2.1.-4. Geological classification of the most common metamorphic rocks. recrystallization of either igneous or sedimentary rock material. During metamorphism, the Classification Rock Description Principal Mineral Constituents rock remains essentially solid; if remelting takes place, magma is produced, and metamor- Contact Hornfels Micro-fine grained Feldspar, Quartz, Mica phism becomes magmatism. Metamorphism is induced in solid rock as the result of pro- nounced changes in the temperature (200-800°C), pressure and chemical environment. These Regional Quartzite Fine grained Quartz, Feldspar changes affect the physical and chemical stability of a mineral assemblage, and metamor- Marble Fine to coarse grained Calcite or Dolomite phism results from the establishment of a new equilibrium. The rock’s composition changes Gneiss Medium - fine grained Feldspar, Hornblende to minerals that are more stable under the new conditions and the minerals arrange them- Slate Rock cleavage Kaolinite, Mica selves through the production of textures that are better suited to the newenvironment. Phyllite Cleavage surfaces Mica, Kaolinite Metamorphism thus results in partial or complete rock recrystallization, with the production Schist Finely foliated Feldspar, Quartz, Mica of new textures and new minerals. Felsic Gneiss Coarsely foliated, banded Feldspar, Quartz, Mica Heat, pressure, and chemically active fluids are the driving forces in metamorphism. Heat Argillaceous rock is mainly comprised of two types of shale: consolidated and cemented. may be created by increasing temperature with depth or by contiguous magmas. There are Both are normally closely bedded or laminated. The former is reasonably strong in a dry two kinds of pressure: hydrostatic (uniform) pressure, which leads to a change in volume; state, but weak when wet; the latter tends to have intermediate strength under most condi- and directed (shear) pressure, which leads to a distortion of shape. Uniform pressure results tions, but is easily deformed under pressure. The problems encountered when mining, tunnel- in the production of granular, non-oriented structures; directed pressure results in the pro- ing or building foundations in this rock type are immediately apparent. duction of parallel or banded structures. Uniform pressure affects the chemical equilibrium by promoting a volume decrease, i.e. the formation of minerals of higher density. The action of ROCK MASS DISCONTINUITIES chemically active fluids is critical in metamorphism, since even when it does not add or sub- tract material from the rock, it promotes reaction by solution and redeposition. When it adds A rock mass is generally considered to be a linear elastic material in the absence of specific or subtracts material, the process is called metasomatism. It is likely that some degree of information on rock mass discontinuities. Most rock formations are fractured to some extent; metasomatism accompanies metamorphism. Water is the principal chemically active fluid, and where fracture planes represent non-continuous structural elements in an otherwise continu- it is aided by carbon dioxide, boric acid, hydrofluoric and hydrochloric acids as well as other ous medium. The stability of rock slopes and underground excavations are two areas of geot- substances, often of magmatic origin. echnical engineering in which the effect of intact rock properties is perhaps less dominant than the influence of rock mass discontinuities. Two major types of metamorphism are commonly recognized: thermal (contact) metamor- phism, and regional metamorphism. Contact metamorphism is created around bodies of plu- The structural mapping of rock formations consists of identifying the rock type, its distribu- tonic rocks. In this case, the temperature of metamorphism was determined mainly by prox- tion and degree of fracturing, and rating the predominant types of discontinuities. For practi- imity to the intrusive magma, which may also have given off chemically active fluids that cal use, this information must be accurately structured by geotechnical classification systems stimulated recrystallization of the country rock. Regional metamorphism, as the name specially designed for predicting rock mass behavior regarding structural stability and excava- implies, is metamorphism developed over large regions, often over thousands of square kilo- tion performance in rock. (FIGURE 2.1.-3.) meters in the root regions of fold mountains and in Precambrian terrain. (Table 2.1.-4.) Joint Plane The earth´s crust is made up of 95% igneous rock, 5% sedimentary rock and an insignificant proportion of metamorphic rock. This does not, however, give a completely accurate Intact Rock picture of the kind of rock likely to be encountered in engineering projects. It is assumed that the earth’s crust is 30 - 50 km thick. Virtually all major projects take place within the first few kilometers of the surface that contain the major part of sedimentary rocks. An engi- FIGURE 2.1.-3. Illustration of O O typically fractured rock mass by a ´ O neer working on or near the surface must often contend with rock that is primarily sedimen- single set of joints; and a simplified tary or metamorphosed. In addition, a high percentage of sedimentary rock is argillaceous, geotechnical model consisting of while the majority of the rest is arenaceous or calcareous. regularly spaced joints ƒ of similar strength. Fractured Rock Mass Geotechnical Interpretation 2. Material Properties 18 19 ROCK EXCAVATION HANDBOOK When two or more intersecting fracture sets are present in the rock mass, an equivalent or rate (unless the operator changes the set-point values) but results in reduced mean tool mean fracture spacing based on the accumulated volumetric fracture plane area is: forces when excavating increasingly fractured rock. (cid:181) = arcsin [ sin f • sin ( r - s ) ] Omean= ( •1 / Oset)-1= ( •fracture area per m3)-1= [ m2/m 3]-1 Omean= [ 11 + 0 1, 5 + 0 1, 5 ]-1 = 0,2m 2.2 MECHANICAL PROPERTIES AND ROCK BEHAVIOUR In the NTH tunnel boring performance classification system, fracture types are grouped into Rock strength, or rock resistance to failure under load, is a mechanical rock property mainly four classes based on fracture strength (aperture or openness, persistence, surface roughness dependent on the nature of the rock itself. Rock cuttability, on the other hand, depends not and waviness, and infilling material) : only on the rock, but also on the working conditions as well as the cutting process (depth of cut, tool size, cutting speed, axial force, presence and extent of wetting, etc.). Therefore, the - Systematically fractured rock mass characterized by: environment for rating rock cuttability/drillability is continuously changing as rock excava- - parallel-oriented joint sets (rated Sp) tion methods improve. - parallel-oriented fissure sets (rated St) - foliation or bedding planes, or parting sets (rated St) Systems for rating rock cuttability and drillability for specific cutting/drilling methods (such - Non-fractured rock mass (rated St 0) as percussive drilling, rotary drilling, drag-tool and roller-disk cutting etc.) have been devel- - Marked single joints (rated ESP) oped resulting in separate rating systems for each method. The rating systems are not direct- - Shear zones - evaluation of necessary ground support work rather than increased net exca ly connected, making it difficult to compare different cutting/drilling methods. Additionally, vation rates is required they tend to be outdated as cutting/drilling technologies develop. The combination of fracture type or fracture strength rating, fracture set spacing and fracture A variety of apparatus and procedures has been developed for measuringmechanical rock prop- plane orientation to the tunnel axis forms the basis of the rock mass fracture factor ks. The erties. This has simplified the study of cutting/drilling processes including the effects various fracture factor ksfor fissures and foliation planes is shown in FIGURE2.1.-4. mechanical rock properties and other factors have on rock cutting/drilling performance. Mechanical rock properties may be grouped as follows: 1. Strength IV 5 cm - Resistance to (bulk) failure under elementary stresses such as compression, tension or 4 shear - Effect of confining pressure, temperature, strain rates, pore- fluid pressure, specimen size, etc. on strength properties 3 III - IV 2. Deformability - Resistance to change of shape or volume 2 - Elastic and thermal expansion constants FIGURE 2.1.-4. Fracture III 10 cm factor ks for full-face 3. Hardness tunnel boring performance prediction as a function 1 II 20 cm - Resistance to a local (surface) failure by indentation or scratching of fissure class rating, angle I 40 cm aand the mean spacing 36 O 4. Fracture toughness between weakness planes. - Resistance to fracture propagation 0(cid:176) 20(cid:176) 40(cid:176) 60(cid:176) 80(cid:176) 5. Coefficients of friction TBM advance rates are more or less proportional to the fracture factor ks. However, unlike - Resistance to sliding of two bodies with planar surfaces in contact full-face tunnel boring machines, partial face cutting machines, like the TM60, are typically equipped with a profile cutting control system which maintains the tool depth of cut at a 6. Crushability and millability preset value. Thus the degree of rock mass fracturing does not affect the TM60’s net cutting - Resistance to comminution (reduction of a substance to a powder)