Article
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Abrasion on tunnel boring machine (TBM) cutters may be critical in terms of project duration and costs. Several researchers are currently studying the degradation of TBM cutter tools used for excavating hard rock, soft ground and loose soil. So far, the primary focus of this research has been directed towards abrasive wear. Abrasive wear is a very common process in TBM excavation, but with a view to the environment in which the tools are working, corrosion may also exert an influence. This paper presents a selection of techniques that can be used to evaluate the influence of corrosion on abrasion on TBM excavation tools. It also presents the influence of corrosion on abrasive wear for some initial tests, with constant steel and geomaterial and varying properties of the excavation fluids (soil conditioners, anti-abrasion additives and water). The results indicate that the chloride content in the water media greatly influences the amount of wear, providing evidence of the influence of corrosion on the abrasion of the cutting tools. The presence of conditioning additives tailored to specific rock or soil conditions reduces wear. However, when chloride is present in the water, the additives minimise wear rates but fail to suppress corrosion of the cutting tools.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Micro fractures, on the other hand, create weak edges and facilitate grain breakage. The cavitation effect dominates at low frequencies, and smaller fragments are attained by ultrasonic waves with low frequency (Brennen, 1995;Ensminger and Bond 2012). Liquid jets are formed by the bursting of cavitation bubbles at medium and high frequencies (F > 200-400 kHz) (Suslick 1989;Kurimoto et al. 2008;Ensminger and Bond 2012;Güngören 2016;Honda 2017;Imai 2017). ...
... The cavitation effect dominates at low frequencies, and smaller fragments are attained by ultrasonic waves with low frequency (Brennen, 1995;Ensminger and Bond 2012). Liquid jets are formed by the bursting of cavitation bubbles at medium and high frequencies (F > 200-400 kHz) (Suslick 1989;Kurimoto et al. 2008;Ensminger and Bond 2012;Güngören 2016;Honda 2017;Imai 2017). High frequencies are commonly preferred in medical applications. ...
... The most common corrosion type within seawater and SLESbased foaming agents is pitting/crevice corrosion. In the literature, many studies have examined pitting corrosion (Reinhart and Jenkins 1972;Heiser and Soo 1995;Revie and Uhlig 2008;Espallargas et al., 2015, Zhang et al. 2017Huang and Zhang 2018). ...
Article
In urban tunneling with an earth pressure balance-tunnel boring machine (EPB-TBM), highly plastic clays or sticky clay containing fine-grained sediments makes tunneling conditions more difficult. The proper amount and consistency of the ground conditioning chemicals to be used for the excavation of these difficult or complex geological units are also controversial. Due to the lack of proper management and optimization of such chemical foaming agents in accordance with the excavation material and tunneling method, some environmental impacts may occur. However, environmental pollution and its effects, in other words, the ecological costs emerged as a result of exposure to these chemicals, can sometimes be ignored.In this study, the use of seawater is proposed as a ground conditioning agent in EPB-TBM operations and the use in addition of ultrasound wave energy application on fine-grained and highly plastic sedimentary clays conditioned with seawater.Preliminary analyses and evaluations of the new eco-technical combination indicate that the seawater can easily compete with existing sodium-based foaming agent (SLES) on a laboratory scale by providing the required dispersive effect, which can be enhanced with ultrasonic applications.
... According to Alber (2008) and Macias et al. (2015), abrasive wear is the most common wear mechanism for the TBM disc cutter. Lisleurd (1997), Barzegari et al. (2015), and Espallargas et al. (2015) described two primary modes of abrasive wear for disc cutters operating in hard rocks, namely two-body abrasion and three-body abrasion, whereas Espallargas et al. (2015) found three-body abrasion mode in soft ground conditions. ...
... According to Alber (2008) and Macias et al. (2015), abrasive wear is the most common wear mechanism for the TBM disc cutter. Lisleurd (1997), Barzegari et al. (2015), and Espallargas et al. (2015) described two primary modes of abrasive wear for disc cutters operating in hard rocks, namely two-body abrasion and three-body abrasion, whereas Espallargas et al. (2015) found three-body abrasion mode in soft ground conditions. ...
Article
Full-text available
LCPC rock abrasiveness test is gaining popularity for quick estimation of rock and soil abrasiveness in the preliminary site exploration stage of tunneling projects. However, there are parameters such as test propeller hardness and testing time, which may affect the test results thereby influencing the tool wear rate estimates of the tunneling machines employed in those projects. This study evaluates LCPC rock abrasiveness test by using both the standard (grade XC 12; 60-75 HRB) steel and hard cold work tool (54-56 HRC) steel propellers. It is found that the wear in the case of hard steel propellers, ABRh (g/t), is almost 70% less than that in the ABRs (g/t) of standard/soft steel propellers. It is established that 40–60% of the propeller wear occurs during the first 2 min of testing. Moreover, bentonite slurry as a conditioning agent produced promising results in the reduction of ABRh (g/t) values in contrast to the unconditioned test results. The correlation of LCPC test parameters ABRh (g/t) and BRh (%) with the geomechanical rock properties and rock wear indices especially Schimazek’s F value and rock abrasiveness index (RAI) show similar trends to the ones obtained using soft steel propellers in the previous studies. However, breakability BR (%) is found to have no appreciable difference once measured using both the soft and hard steel propellers.
... Recently, abrasive wear and the relation with rock and steel properties as well as other parameters involved in the tribological system have been analysed by several researchers (Petrica et al. 2013;Ratia et al. 2014;Espallargas et al. 2015;Ellecosta et al. 2015). Petrica et al. (2013) studied wear behaviour and relation with physical and mechanical rock properties. ...
... Ratia et al. (2014) performed an analysis of the effect of abrasive properties on steels and hard metals, concluding that it is essential to consider the contact conditions and the whole wear environment for wear assessments. Espallargas et al. (2015) evaluated the influence of corrosion on abrasive wear on TBM cutter steel during interaction with excavation fluids using several laboratory tests Ellecosta et al. (2015) performed Vickers hardness test with loads up to HV 30. Several rocks and associated disc cutters were tested to evaluate the ability of the method for characterization of rock abrasivity and wear. ...
Article
Full-text available
The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and in order to evaluate the newly developed RIAT test method, a comprehensive laboratory testing program including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.
... The abrasive wear including ploughing, micro cutting, micro fatigue and micro cracking is caused by hard particles sliding against the wearing surface [14,15]. Espallargas et al. [16] proposed that abrasion is the commonest wear mechanism for the disc cutter ring. ...
... When the disc cutter ring cuts rock under different cutting conditions, the wear behavior may show difference. For example, when the cutter ring cuts rock under the seawater condition, its surface may be corroded by seawater during the cutting process [16]. ...
Article
To study the wear behaviors of the tunnel boring machine (TBM) disc cutter ring under drying, water and seawater conditions, a series of cutter-rock wear tests were conducted based on the self-designed TBM cutter performance test bench. The results indicate that the wear behaviors of the cutter ring are affected significantly by wear conditions. The largest mass loss of the cutter ring is under the drying condition, followed by the seawater condition, and the smallest is under the water condition. The differences in mass loss were explained by the cutter force, wear mechanism, and wear debris etc of the cutter ring. These results can provide some references for the wear resistance design and service life prediction of the TBM cutter ring.
... Drill and blast (D&B) tunneling and tunnel boring machine (TBM) tunneling are the two dominating excavation methods in hard rock tunneling (Zare et al. 2016). In recent years, several researchers have extensively studied the parameters effective in rock excavation (Bruland 1998a;Barton 2000; Barla and Pelizza 2000;Blindheim et al. 2002;Yagiz 2002;Thuro and Plinninger 2003;Rostami et al. 2005;Villeneuve 2008;Hassanpour 2009;Farrokh et al. 2011;Espallargas et al. 2015) and provided prognosis models for both D&B and TBM tunneling (Johannessen et al. 1995;Rostami 1997;Thuro 1997;Bruland 1998b;Dahl et al. 2007;Zare 2007;Yagiz 2008;Gong and Zhao 2009;Zhao et al. 2012;Hassanpour et al. 2014;Ellecosta et al. 2015). ...
... Abrasion in TBM cutters may be critical in terms of project duration and costs (Espallargas et al. 2015). Large investments and high geological risk are involved using TBMs. ...
Article
Full-text available
Thorough and realistic performance predictions are among the main requisites for estimating excavation costs and time of the tunneling projects. Also, NTNU/SINTEF rock drillability indices, including the Drilling Rate Index™ (DRI), Bit Wear Index™ (BWI), and Cutter Life Index™ (CLI), are among the most effective indices for determining rock drillability. In this study, brittleness value (S20), Sievers’ J-Value (SJ), abrasion value (AV), and Abrasion Value Cutter Steel (AVS) tests are conducted to determine these indices for a wide range of Iranian hard igneous rocks. In addition, relationships between such drillability parameters with petrographic features and index properties of the tested rocks are investigated. The results from multiple regression analysis revealed that the multiple regression models prepared using petrographic features provide a better estimation of drillability compared to those prepared using index properties. Also, it was found that the semiautomatic petrography and multiple regression analyses provide a suitable complement to determine drillability properties of igneous rocks. Based on the results of this study, AV has higher correlations with studied mineralogical indices than AVS. The results imply that, in general, rock surface hardness of hard igneous rocks is very high, and the acidic igneous rocks have a lower strength and density and higher S20 than those of basic rocks. Moreover, DRI is higher, while BWI is lower in acidic igneous rocks, suggesting that drill and blast tunneling is more convenient in these rocks than basic rocks.
... Oparin and Tanaino (2015) presented a method for determining the characteristics of rock abrasivity based on physical, mechanical, and structural properties of rocks, and concluded that the wear process, in addition to the material properties, depends on the surface conditions of the contact area between disc and rock. Espallargas et al. (2015) examined the corrosion effect of excavation fluids (water, soil conditioners, and anti-abrasion additives) on the wear of the TBM disc cutters using laboratory tests. The results showed that corrosion has a significant effect on the wear of the discs. ...
Article
Disc cutters are the dominant cutting tools used in tunneling by rock TBMs. During the operation, disc cutters wear out and should be replaced with new ones. The wear rate of the disc cutters can be defined in terms of rolling distance/time and volumetric wear. Furthermore, the wear rate can be attributed to the mass loss. The wear prediction models for disc cutter have been developed on the basis of the intact rock abrasion indices, most commonly Cerchar abrasivity index (CAI). Examination of these models and comparing their results with actual wear observed in the Kerman water conveyance tunnel (KWCT) project show that the available models are conservative. In other words, reliance only on the intact rock abrasion does not offer an accurate prediction of the wear rate of the disc cutter. Therefore, rock mass conditions should also be considered in the calculations. The current study shows that volumetric mass loss is a more appropriate method to predict wear life of disc cutters due to consideration of various geometric parameters such as spacing between disc cutters, penetration rate, installation radius, and bored length. Subsequently, a new empirical prediction model is proposed by nonlinear multivariable regression based on CAI as a rock material parameter and RQD (rock quality designation) as a rock mass parameter to estimate the cumulative volumetric mass loss of disc cutters. For ease of using the model, a chart is introduced that determines the wear on the disc cutters based on the CAI and RQD.
... The impact friction was generated by ejected rock particles. Espallargas et al. [17] studied the influence of corrosion on cutter steels used in tunnel boring machines by reciprocating ball-on-disk setup. A 6-mm-diameter H 13 steel ball was slid against rock materials at 5 N load in the presence of water-based liquid media with conditioning additive, such as ABR 5 and SLF 41. ...
Article
Full-text available
Rock drilling performance of O1 tool steel was simulated at laboratory scale using mortar specimens. Mortar specimens were prepared with cement-to-sand ratio of 1:2 and cured for 7 and 30 days to simulate soft and hard rocks, respectively. Rock drilling performance of tool steel was measured in terms of corrosion, tribocorrosion, and wear of mortar specimens in the presence of 3.5 wt% NaCl solution. The tribocorrosion properties were measured by modification of a tribometer and adding a three-electrode setup where tool steel pin was used as a working electrode counterpart against mortar sample. The effect of mortar on corrosion behavior of tool steel was measured by potentiodynamic polarization tests, while the tribocorrosion was monitored by open-circuit potential tests. It has been found that the mortar specimens negatively affect the corrosion and tribocorrosion, and thus improve the corrosion performance of tool steel. This effect was more prominent against 7-day-cured mortar specimen compared to 30-day-cured specimen. Various factors, such as mechanical properties of rock material, cutting fluid, drilling mechanism, and dissolution of minerals, which can affect the tool life are discussed.
... The shape curves of the six studied cutterheads are illustrated in Fig. 14. Linear and exponential functions are used to fit the data, the adjusted R-square (R 2 ) is used to evaluate the correlation, and the averaged sum of squared errors (SSE av ) is used to evaluate the data fluctuation (Draper and Smith 1998). The higher the R 2 , the better the correlation, while the lower the SSE av , the lower the fluctuation of the data. ...
Article
Full-text available
The consumption of TBM disc cutters is influenced by the ground conditions (e.g. intact rock properties, rock mass properties, etc.), the TBM boring parameters (e.g. thrust, RPM, penetration, etc.) and the cutterhead design parameters (e.g. cutterhead shape, cutter layout). Previous researchers have done much work on the influence of the ground conditions and TBM boring parameters on cutter consumption; however, limited research has been found on the relationship between the cutterhead design and cutter consumption. The purpose of the present paper is to study the influence of layout on consumption for the TBM face cutters. Data collected from six tunnels (i.e. the Røssåga Headrace Tunnel in Norway, the Qinling Railway Tunnel in China, tubes 3 and 4 of the Guadarrama Railway Tunnel in Spain, the parallel tubes of the Vigo–Das Maceiras Tunnel in Spain) were used for analysis. The cutter consumption shape curve defined as the fitted function of the normalized cutter consumption versus the cutter position radius is found to be uniquely determined by the cutter layout and was used for analysis. The straightness and smoothness indexes are introduced to evaluate the quality of the shape curves. The analytical results suggest that the spacing of face cutters in the inner and outer parts of cutterhead should to be slightly larger and smaller, respectively, than the average spacing, and the difference of the position angles between the neighbouring cutters should be constant among the cutter positions. The 2-spiral layout pattern is found to be better than other layout patterns in view of cutter consumption and cutterhead force balance.
... Based on the Laboratoire Central des Ponts et Chaussées (LCPC) test developed by the LCPC, France, Thuro et al. [13] studied the effects of grain size, grain angularity, soil mineral, and water saturation on soil abrasivity. Espallargas et al. [14] investigated the cutting tool corrosion, since the environment in which the tools operate could be corrosive, and then the shield cutting tools made of metal might be affected by corrosion. Moreover, soil conditioning done by injecting foam, bentonite slurry, water, or polymer in the cutterhead, bulk chamber, and screw conveyor of EPBS is usually conducted to change the natural properties of soils to be excavated. ...
Article
Full-text available
Cutting tool wear is a critical problem for tunneling in soft ground with the earth pressure balance shield. In this study, a cutting tool tester was developed in the China University of Geosciences in Beijing, and a series of tool wear tests were conducted to investigate the characteristics of tool wear in granular soils. The characteristics of cutting tool wear can be quantitatively assessed through the ratio (M 0 − M)/M 0 (i.e., tool wear rate, %; M 0 and M are the mass of the tested blocks before and after the wear test, respectively). The effects of five important factors, including mineralogy, moisture, soil conditioner, test time, and sand content, on tool wear were considered in various test conditions. According to the primary test results, it is observed that (1) high soil hardness produced significantly higher tool wear than low soil hardness in dry condition; (2) with increasing water content, the tool wear gradually increased to a maximum value and then decreased; (3) the foam conditioner mixed in sandy gravel reduced the tool wear dramatically regardless of the cutting tool material, e.g., cemented carbide and Q235 steel; (4) the tool wear increased with the test time in the dry sand mixture, and their relationship showed a good agreement with a power function; and (5) the tool wear decreased as the sand content increased in dry sand-gravel soil mixtures. The reasons for these phenomena were also explored.
... The image shows a typical tempered martensite microstructure with some paler areas of retained austenite. The steel has been die-forged and heat-treated to increase its hardness [14]. ...
Article
Cutter consumption and parameters such as cutter ring wear has a great relevance in the overall excavation time and cost in hard rock tunnel boring machines (TBMs), especially in hard rock conditions. Cutter wear involves a complex tribological system that interacts also with the geologicy of the rock mass. Understanding the processes and failure mechanisms during cutter wear (e.g. modes of contact, wear, load effects) and assessing the influence of temperature on cutter ring wear processes enables new knowledge to be applied to get better cutter consumption predictions and future improvements in cutter ring development. In addition, it might be used to evaluate the suitability of the new rock abrasivity test method (Rolling Indentation Abrasion Test, RIAT) for assessing cutter ring wear.
... Therefore, replacing the worn cutter is an inevitable work during construction. 24,25 Under complex geological conditions, specialized workers are needed to renew worn cutters in the narrow excavation chamber frequently with high pressure, as shown in Figure 2. It might increase the risk of workers' safety and even result in major accidents. 26,27 Manual cutter changing operation requires operators to enter the excavation chamber carrying lighting and hoisting tools under tough environment with high temperature, high humidity, and high pressure. ...
Article
Full-text available
Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.
... When the cutter wears normally, multiple wear mechanisms participate at the same time (Espallargas et al. 2014). Cutter wear is mainly caused by the interaction between the cutter and the rock, and tool wear is composed of direct wear and secondary wear (Hassanpour et al. 2014;Petrica et al. 2013). ...
Article
Full-text available
Disc cutter wear is a crucial problem that influences the working efficiency and security of hard rock tunnel-boring machines (TBMs). When tunneling and rock breaking with TBM, the cutters at the forefront of the cutter head directly contact the tunnel face, where wear is serious due to a harsh working environment. In this study, the Cerchar abrasivity index (CAI) of various rock samples was obtained by using the ATA-IGG I rock abrasion servo system. Additionally, a series of small-size cutter wear experiments were carried out on an SP3-I composite abrasion test platform, and the fitting relationship between cutter wear and rock abrasion value was obtained. A cutter wear prediction method was established by measuring the cutter wear and rock CAI of the project built section and the rock CAI of the project unbuilt section. Based on the experimental results, the effects of different tunneling parameters (penetration speed, rolling speed) and tip width on cutter wear were analyzed. In the study of cutter wear, attention should be paid to the influence of load, vibration and temperature on the cutter wear removal mechanism. It is suggested that wide-tip and narrow-tip cutters should be arranged alternately on a TBM cutter head to give full play to the lateral rock crack ability developed by the wide-tip cutter and the radial rock crack ability developed by the narrow-tip cutter, so as to reduce wear on the cutter and improve the efficiency of TBM rock breaking. The results of this research provide a reference for optimization design and performance selection of a TBM cutter ring and cutter head.
... To date, it has been acknowledged that the wear mechanism of disc cutter is classified as tribochemical reaction, surface fatigue, adhesive wear, and abrasive wear [19]. Among them, abrasive wear is the most common wear form [20]. Ploughing, microcutting, microfatigue, and microcracking are main reasons for the abrasive wear [21,22]. When disc cutters roll on the tunnel face, wear loss is affected by many factors, such as properties of cutter, geological conditions, and operational conditions [23,24]. ...
Article
Full-text available
Argillization is a process in which clay-bearing rocks disintegrate into the clay under the action of high temperature, pressure, and water. When tunnel boring machines (TBMs) excavate in the mudstone, argillization takes place, causing the clogging of the TBM cutterhead. As a result, the penetration rate drops gradually. Abnormal wear might occur. To investigate the evolution of argillization of mudstone and cutter wear during the TBM tunnelling, a series of rotary indentation tests were carried out on the self-designed experimental bench for different loading times. During the test, the temperature and penetration depth of disc cutters were measured in real time. After loading, microstructures of cutting grooves, slacking mudstone, and worn cutter ring were observed by stereomicroscope. Consequently, the evolution of argillization in mudstone and cutter wear were investigated. Experimental results indicate that the argillization process of mudstone by disc cutter can be divided into three stages: mechanical cutting stage, deterioration of mudstone and the formation of slacking mudstone stage, and adherence of slacking mudstone stage. Specifically, at mechanical cutting stage, the rock was cut by cutter directly, causing high frictional heat. Then the microstructure of mudstone was deteriorated due to the water-weakening mechanisms, temperature effect, and mechanical activation effect. Finally, the slacking mudstone was adhered to the disc cutter. Correspondingly, due to the argillization of mudstone, the disc cutter wear goes through the mechanical wear stage, argillization wear stage, and secondary wear stage in sequence. This investigation reveals the rock cutting mechanism of TBM considering the argillization of mudstone. Furthermore, it provides some references for design and operation of the TBM.
... The disadvantage of this model consists in the fact that it does not take into account changing force characteristics in the process of exploitation of the geokhod. For instance, the metal body of the geokhod as well as its executive elements are corrodible and exposed to abrasive wear which inevitably affects the force characteristics and the efficiency of the whole machine in the same way as it happens to tunneling shields [13]. Body resistance to corrosion can be improved through the use of special covers described in work [14]. ...
Article
Full-text available
The article describes the results of a theoretical research of installation of a pumping station into the tail section of a geokhod. It is considered how an increasing weight of the tail section influences power characteristics of geokhod transmission. The research is based on a mathematical model of geokhod's moving through the underground space.
... On the soil-steel interaction in mechanized excavation applications, the effect of grain roundness [24] particle size distribution [25], soil strength [26], and the average hardness of soil grains [27] as well as the shape and speed of the cutting tool [28] have been discussed in the literature. Espallargas International Journal of Mining and Geo-Engineering IJMGE reported the impact of chemical corrosion on the wear of soil cutting tools [29]. ...
Article
Full-text available
ncreasing demand for the application of mechanical excavation techniques in various civil and mining projects has increased the importance of ground abrasive properties and its mechanized excavatability. The accurate prognosis of cutting tools lifetime has crucial importance in the planning of mechanized tunneling projects. Moreover, the precise estimation of the required cutter number for excavating the determined length of a given section in a specific geotechnical condition is one of the main tasks of the project consultants. The main objective of these estimations is to assess the needed time and cost of cutter replacements in the phase of feasibility studies and to plan a proper maintenance schedule. The LCPC testing procedure is one of the simplest and most common soil abrasivity assessment methods. The purpose of the presented study is to investigate the steel – soil interaction during the LCPC abrasion test. The consumed energy of LCPC tests on different abrasive samples was measured. Based on the recorded energy values, a new parameter of wear specific energy of the LCPC test (WSEL) was introduced. The obtained WSEL values showed meaningful correlations with the sample grains size and the sample average hardness. Moreover, the results revealed that the high LCPC abrasion coefficient (LAC) values are relevant to the high consumed energy levels recorded during the tests.
Article
To investigate the specific matching characteristics of Tunnel Boring Machine (TBM) cutter ring properties and rock, matching friction tests for six kinds of TBM cutter ring specimens with different properties and two kinds of typical TBM rock samples were performed on a bespoke TBM cutter performance test bench. The results indicate that the matching characteristics of the TBM cutter ring properties and rock type have significant effects on the wear of a TBM cutter ring and that the specific properties of the cutter rings that demonstrate the best matching characteristics with the two types of rock are different. For the cutter ring that exhibits the best matching behaviours with China granite, the hardness is 58.0 HRC, and the toughness is 3.1 J/cm², while the hardness and toughness for the cutter ring that exhibits the best matching characteristics with Bianco Argento are 57.0 HRC and 3.7 J/cm², respectively. These results provide basic experimental data for the geological matching design of TBM cutter ring properties.
Conference Paper
Full-text available
Disc cutter consumption is of great importance when using the Tunnel Boring Machine (TBM) method for tunnelling in hard rock conditions. Abrasive wear is the most common process affecting cutter consumption; therefore good laboratory tests for rock abrasivity assessments are needed to carry out reliable cutter consumption assessments that enable project planning and control of the risk. A new rock abrasivity test method named Rolling Indentation Abrasion Test (RIAT) has recently been developed. It reproduces wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods by introducing wear by rolling contact on intact rock samples. Detailed cutter consumption data, operational machine parameters and laboratory tests results from a recently finished hard rock TBM project has been analysed in order to evaluate the applicability of the RIAT method to assess cutter consumption in hard rock tunnel boring.
Article
The study evaluates the microstructure, abrasion resistance, and corrosion behavior of newly designed cost-effective (Cr-Mo-W-V) steels. Six steels were designed with the help of computational thermodynamics to achieve a ferritic or duplex matrix with embedded hard carbides. The precursors of alloying elements were two commercial steels, namely HCx® and 316L. The wet abrasion tests and the corrosion tests revealed that the designed Cr-Mo-W-V steels have remarkable abrasion and corrosion resistance compared to the expensive commercial steel used as a precursor (HCx®). The least alloyed steel had the highest abrasion resistance owing to its low matrix/carbide hardness ratio and the presence of small intragranular carbides that led to a greater influence of the microstructure on the abrasion resistance than the hardness. Nickel played a key role in the formation of a passivation layer before the onset of corrosion; however, it must be added along with chromium and molybdenum for improved performance.
Chapter
Research on rock fragmentation mechanism is significant for TBM projects. To study the influence of penetration on the disc cutter force, a numerical simulation was conducted using the software MatDEM based on Discrete Element Method (DEM). A 19 in. disc cutter model was established. Four rock materials characterised by different strength properties and two layered rock combinations were assigned to the large-scale rock specimen. The rock breaking processes of single cutter were simulated at penetrations of 2, 4, 6, 8 and 10 mm respectively. Through the monitoring and analysis of cutter forces and specific energy (SE) changes, it is found that for the same type of rock material, the average normal force and rolling force both increase as the penetration increases, but the growth trends have shown a significant difference due to the rock strength properties. The SE can be significantly affected by penetrations and there is an optimal penetration, respectively, to minimize the SE value for different types of rock. In addition, the dissimilar rock combinations have a significant impact on the cutter forces. To verify the simulation law of disc cutter forces with respect to penetrations, the linear cutting machine (LCM) test has been carried out. The consistency of the comparison results of the two methods indicated that combining the simulation of MatDEM with the LCM test can explore the rock fragmentation mechanism of the disc cutter more deeply and comprehensively.
Article
To improve the wear resistance of disc cutters for tunnel boring machines (TBMs), this study is devoted to investigating the effects of rocks and cutter ring properties on the wear behaviors of disc cutters and the matching characteristics between the cutter ring properties and hard rocks. The cutter-rock wear tests were performed, and the results show that the cutter ring properties and rock types significantly affect the cutter ring wear. The mass losses of cutter ring samples sliding against different types of hard rock are different and vary with the cutter ring properties because of the discrepancies of loads, vibrations, rock properties and transition of the wear mechanisms. Finally, matching characteristics between the cutter ring properties and hard rocks are revealed.
Article
Full-text available
The current study investigates the wear life of button bits and rate of penetration (ROP) of rotary-percussive drilling machines by employing geotechnical rock properties. According to the research plan, three hydropower projects and six active mining quarries in Pakistan were included. The field work included recording of drill bit consumption (m/bit) and measurement of penetration rate (m/min) from the 11 selected rock units. A comprehensive laboratory testing plan on the collected rock units was carried out to include rock abrasivity assessment [CERCHAR (CAI), LCPC (ABR) and abrasion value steel (AVS) tests], NTNU/SINTEF drillability parameters [Sievers’ J-value (SJ), brittleness value (S20), Cutter Life Index™ (CLI) and Drilling Rate Index™ (DRI)] and physico-mechanical properties [uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), porosity (n), density (ρ), p wave velocity (Vp), Schmidt rebound hardness (SRH) and brittleness index (B3)]. Moreover, XRD analyses were performed to compute equivalent quartz content (EQC %), rock abrasivity index (RAI) and Vickers hardness number of rock (VHNR). The least square regression technique was employed to predict bit life from geotechnical rock properties. Dependence of ROP on geotechnical rock parameters was also discussed. Finally, two multiple linear regression models were also proposed for the estimation of bit life based on the included geotechnical rock properties. The developed multi-variable models were validated using the F-test statistical method. The correlations so developed are particularly proposed for rock engineers involved in rock drilling projects.
Article
Using tunnel boring machines to excavate high-strength intact rock masses is becoming more common. Due to the interactions between disc cutters and rocks, abnormal wear of disc cutters, especially cutter chipping, has become a common phenomenon. Existing research has mainly focused on normal wear of disc cutters without addressing abnormal wear cases. This study used the disc cutter consumption data of a tunnel project in China to investigate the abovementioned problem based on field research. According to the failure patterns and fracture surface characteristics, the cutter chipping patterns were mainly categorized into four types: granule chipping, patch chipping, primary collapse, and secondary collapse. To further simulate the evolution of disc cutter chipping, based on the linear plastic bond model, a new contact model called the modified plastic bond (MPB) model was proposed to solve the metal simulation problem in Particle Flow Code software. To this end, a set of uniaxial tensile and compressive tests were initially conducted to verify the applicability of the MPB model. Then, a series of three-dimensional rock-cutting simulation tests were conducted to reflect the evolutionary processes involved in each type of cutter chipping. The cutter chipping mechanism and morphological characteristics were classified and summarized in detail. The results revealed that the cutting speed and penetration growth led to a rising trend in the probability and intensity of the cutter chipping. The presence of initial defects also induced an adverse effect on the service life of the cutter. The results indicated suitable working conditions for the cutter and suggested ways to control tunneling parameters and avoid frequent cutter chipping cases.
Chapter
In simple words, tribocorrosion is a material degradation resulting from the combined action of corrosion and wear. More in detail, the ASTM G40-10b defines tribocorrosion as a form of solid surface alteration that involves the joint action of relatively moving mechanical contact and a chemical reaction in which the result maybe different in effect than either process acting separately.
Article
The cutter ring of the TBM disc cutter is the main tool that directly contacts and cuts the rock. The cutter ring is prone to wear during the tunneling process, and the lower wear life will drastically reduce the tunneling efficiency and increase the construction cost. The working temperature of the cutter ring is an important factor affecting its wear resistance. TBM cutter cooling measures do not produce satisfactory results when tunneling in hard rock environments. When the cooling is not timely, the working temperature of the disc cutter ring will reach more than 400℃. Therefore, this paper carried out the cutter ring and rock wear experiment with water and air as the cooling medium. After analyzing the influence of different cooling methods on the weight loss, the working temperature and the wear mechanism, the result is obtained as follows: (1) The working temperature under water mist cooling is the lowest, and its wear loss is reduced by 65.2% compared with the non-cooling state. Under 30m/s air flow rate cooling condition, the weight loss dropped by 22.5%. (2) The hardness of the cutter ring material will gradually decrease as the temperature rises. As the working temperature increases, the ploughing wear mechanism with plastic characteristics will appear. (3) The lubrication of water and the drop in the vertical force load after the rock absorbs water are also important factors to reduce the wear of the cutter ring.
Article
Connections between surface and internal cracks are critical to rock fractures between kerfs. To promote rock fracture, a modified cutter containing wedge-shaped cutting teeth was invented. Then, comparison linear cutting tests were performed using a CCS and a modified cutter. The results indicate that the modified cutter can promote surface crack incisions (most frequently initiating from the contact points between cutting teeth and rock) and generate an increased number of chips. The modified cutter consumes nearly the same energy as the CCS cutter. Thus, the cutting efficiency of the modified cutter is higher. To further investigate the underlying mechanism, the dynamic stress evolution between kerfs (using PFC 3D) is studied. The numerical results agree well with laboratory tests in rock fractures and indicate that tensile stress concentrations are responsible for the initiation of internal and surface cracks. In addition, theoretical analysis using elastic–plastic fracture mechanics properly explains the formation of the regularly distributed surface cracks caused by the modified cutter.
Article
The lack of reliable methods for evaluation of soil abrasivity and revealing the effects of different parameters on wear rate are nowadays considered as a deficiency in geotechnical investigation during feasibility study, design and construction phases of tunneling projects with the use of tunneling boring machine (TBM). The subject is recently attracts a broad international attention and focus. The background of existing standard test methods are reviewed and wear types occurrences in TBM tunneling are discussed in this paper. A new soil abrasion testing system is developed which is called Soil Abrasion Testing Chamber (SATC) and the results of soil abrasion tests are compared with results of the commonly used tests such as: Cerchar, LCPC and SAT tests. Some of the most influencing factors including presence of water, bentonite slurry, soil particle size, quartz content, water pressure and confining chamber pressure are considered for the use of the new devise. The test results indicate that the soil abrasivity tends to increase with the increasing of soil particle size, bentonite slurry, soil pressure and quartz content. The effect of water on abrasivity varies for different types of soil. The soil abrasivity decreases with the increase of water pressure. The internal friction does not seem to have any influence on the wear rates measured with the new proposed apparatus.
Thesis
Full-text available
The Drilling Rate Index DRI, the Bit Wear Index BWI and the Cutter Life Index CLI are indirect measures for the drillability of a rock type. The report presents two catalogues of laboratory test data of 2038 rock samples tested at the Engineering Geological Laboratory at NTNU and SINTEF Rock and Mineral Engineering. In Catalogue 1 (Chapter 2) the rock samples are sorted alphabetically by rock name and chronologically by time of testing. Catalogue 2 in Chapter 3 shows the same rock samples sorted by county for the Norwegian samples and by continent for the foreign samples, and alphabetically and chronologically for each county or continent.
Article
Full-text available
The Norwegian University of Science and Technology (NTNU), SINTEF Rock Engineering and BASF Construction Chemicals have jointly developed a new test device called the Soft Ground Abrasion Tester (SGAT). The ambition and purpose of the design of the test and the applied test procedure is to replicate an in situ soil - TBM excavation tool contact, in a small and simplified scale. The current development is attempting to bridge a gap when it comes to estimating soft ground and soil abrasivity, as earlier research on e.g. the NTNU/SINTEF Soil Abrasion Test (TM) (SAT) shows that it does not catch up all driving factors for soft ground and soil abrasivity directly. The paper summarizes the development of the SGAT apparatus, and shows its capabilities to evaluate, quantify and compare how the soil mineralogy, water content, pressure, compaction, and the use of soil conditioning additives influences the wear rate on the SGAT excavation tool. During testing the required torque and thrust are monitored and logged, making it possible to measure various soil-soil conditioning matrixes requirement for operational parameters.
Article
This book presents a systems analysis approach to tribology. After a brief introduction to the concept of systems analysis, a general theory of trib ology is derived, followed by detailed analysis of tribological systems such as friction, wear and lubrication; the effects of these processes on machine elements are then analysed. Finally, chapters are devoted to both tribometry and the presentation of data. (G.P.)
Article
Four approaches to tribocorrosion are reported in the literature:the synergistic, the mechanistic, the third body and the nanochemical wear. They have been successfully used to describe the behaviour of passive metals in sliding contacts exposed to corrosive media. However, owing to the large number of variables playing a role in tribocorrosion systems (i.e. nature of the materials in contact, electrochemical conditions, chemistry, temperature, mechanical conditions), the validation of tribocorrosion mechanisms and models is complex. The aim of this chapter is to give an overview of the basis and limitations of the proposed tribocorrosion mechanisms and to introduce some guidelines for the future challenges in the field of tribocorrosion.
Article
As with the previous edition, the third edition of Engineering Tribology provides a thorough understanding of friction and wear using technologies such as lubrication and special materials. Tribology is a complex topic with its own terminology and specialized concepts, yet is vitally important throughout all engineering disciplines, including mechanical design, aerodynamics, fluid dynamics and biomedical engineering. This edition includes updated material on the hydrodynamic aspects of tribology as well as new advances in the field of biotribology, with a focus throughout on the engineering applications of tribology. New to this edition are end-of-chapter problems and an accompanying solutions manual, increasing the books value as a textbook. The book offers an extensive range if illustrations which communicate the basic concepts of tribology in engineering better than text alone. All chapters include an extensive list of references and citations to facilitate further in-depth research and thorough navigation through particular subjects covered in each chapter.
Article
TBM excavation has become increasingly common, despite the fact that precise evaluation of certain risks has not kept pace with the use of these machines. One of the risks easily overlooked by Engineer and Contractor alike are the effects of abrasive ground on the costs and schedule of a given project. The impacts of worn and damaged TBM cutterheads have been observed on hundreds of tunnel projects around the world. It would appear that a reliable prognosis of the abrasiveness of ground on a project would be of great importance for designers, clients and contractors alike. Several well acknowledged test and prognosis methods already exist for rock; however, there is only very limited knowledge available to describe the abrasiveness of soil and its impact on wear on soft ground TBMs. This three-part article examines existing approaches to the problem and suggests a new approach based on a current project undergoing design. Defining wear For the purposes of the following discussion it is necessary to define the terms to be used, primary wear and secondary wear. By primary wear we refer to the wear on the excavation tools and surfaces such as drag bits, disc cutters, scrapers and buckets, etc., which are designed for excavation and to be replaced at appropriate intervals. Secondary wear, on the other hand, occurs when the primary wear on the cutting tools described above is excessive, which leads to wear of the structures designed to hold or support the tools in place, such as cutting head spokes or cutter mounting saddles, and wear on other surfaces not anticipated by the designers and TBM manufacturers (Herrenknecht and Frenzel, 2005 [1]).
Article
The demand for representative rock property parameters related to planning of underground excavations is increasing, as these parameters constitute fundamental input for obtaining the most reliable cost and time estimates. The Brittleness Value (S20), Sievers’ J-Value (SJ), Abrasion Value (AV) and Abrasion Value Cutter Steel (AVS) have been used extensively at NTNU/SINTEF since the 1960s in connection with drillability testing of rock samples. Nearly 3200 samples originating from projects in 50 countries have so far been tested, and the method and associated prognosis model are internationally recognised for giving reliable estimates of time and cost for tunnelling. A classification of the NTNU/SINTEF drillability indices Drilling Rate Index™ (DRI), Bit Wear Index™ (BWI) and Cutter Life Index™ (CLI) has been available since 1998, but until now no official classification has been available for the individual tests used to calculate these indices. In this paper, classifications of the NTNU/SINTEF drillability test methods Brittleness Value (S20), Sievers’ J-Value (SJ), Abrasion Value (AV) and Abrasion Value Cutter Steel (AVS) tests will be described in detail. The presented classifications of the individual tests are based on statistical analysis and evaluations of the existing test results recorded in the NTNU/SINTEF database.
Book
Material Properties That Influence Surface Interactions. Surface Interactions. Friction. Types of Wear. Adhesive Wear. Abrasive and Other Types of Wear. Lubrication. Adhesion. Appendix. Sample Problems. Index.
Article
Prediction of the tool wear and life, as well as secondary wear on machine components, in soft ground tunneling using shielded machines with a pressurized face has been a difficult task due to the lack of a universally accepted measurement system for soil abrasion. While some existing abrasion tests have been adopted in recent years to measure soil abrasion, these systems have inherent mismatches with the actual working conditions at the tunnel face. This paper reviews some of the background studies in this area and introduces the initial steps towards the development of a new soil abrasion testing system. The design and operational parameters for a proposed device that is under development for measuring a soil abrasion index are discussed and the preliminary results of testing on various soil samples are presented.Highlights► Soil abrasion has a major impact on soft ground mechanized tunneling but not well quantified in contract documents and source of delays and claims. ► Previous soil abrasion tests are reviewed and initial steps for developing a new soil abrasion index are discussed. ► The preliminary results of testing on various soils have been presented and showed a promise for future application in soft ground tunneling.
Tribocorrosion mechanisms in sliding contacts Tribocorrosion of passive metals and coatings Abrasivity of soils in TBM tunnelling
  • Ai
  • N Espallargas
  • Fe
  • J Holzhä
AI, Espallargas N (2011) Tribocorrosion mechanisms in sliding contacts. In: Landolt D, Mischler S (eds) Tribocorrosion of passive metals and coatings. Woodhead Publishing, Lausanne Nilsen B, Dahl FE, Holzhä J, Raleigh P (2006) Abrasivity of soils in TBM tunnelling. Tunnels Tunnelling Int 3:36–38
Engineering tribology Butterworth-Heinemann, Burlington Verhoef PNW (1997) Wear of rock cutting tools—implications for the site investigation of rock dredging projects
  • Stachowiak Gw
  • Batchelor
Stachowiak GW, Batchelor AW (2005) Engineering tribology, 3rd edn. Butterworth-Heinemann, Burlington Verhoef PNW (1997) Wear of rock cutting tools—implications for the site investigation of rock dredging projects. Balkema, Rotterdam. ISBN: 90-5410-434-1
Formerly known as Meyco SLF 41). Soil conditioning foam for Tunnel Boring Machines
  • Masterroc Slf
BASF, MasterRoc SLF 41 (Formerly known as Meyco SLF 41). Soil conditioning foam for Tunnel Boring Machines. http://www. basf-cc.com.au/en/products/SolutionsforMining/TunnelBoring Machines/TBMFoams/MasterRocSLF41/Pages/default.aspx
Lubrication (tribology) education and research: a report on the present position and industry's needs. Her Majesty's Stationery Office
  • P H Jost
Jost PH (1966) Lubrication (tribology) education and research: a report on the present position and industry's needs. Her Majesty's Stationery Office, London
Cultural impediments to practical modeling of wear rates
  • K C Ludema
Ludema KC (1991) Cultural impediments to practical modeling of wear rates. In: Ludema KC, Bayer RG (eds) Tribological modeling for mechanical designers, ASTM STP 1105. American Society for Testing and Materials, Philadelphia
Corrosion and corrosion control
  • R R Winston
  • H H Uhlig
  • RR Winston
Liquid anti-abrasion agent for hard rock & EPB Tunnel Boring Machines (TBM)
  • Masterroc Basf
  • Abr
Tribocorrosion mechanisms in sliding contacts
  • A I Muñoz
  • N Espallargas
  • AI Muñoz