Determining abrasivity with the LCPC test

There are currently no recognised prediction models available for the estimation of tool wear in shield tunnelling in soil. This paper describes the current state of knowledge through the interpretation of the available index tests, available correlations and analogies to hard rock. Then follows a discussion of the essential soil properties and the process-related interactions, which can also determine tool wear in soil.

Section: Fig 3 Correlation Of the Rai (Ucs X Eqc) With The Cai [10]mentioning

confidence: 99%

Abrasiveness and tool wear in shield tunnelling in soil / Abrasivität und Werkzeugverschleiß beim Schildvortrieb im Lockergestein

Köhler¹,

Maidl²,

Martak³

2011

“…The equivalent quartz content represents the entirety of the minerals that cause wear [8]. It is calculated from the sum of the products of mineral contents and their relevant grinding strengths according to Rosiwal [7] in relation to that of quartz.…”

Section: Wear and Abrasivenessmentioning

confidence: 99%

“…Another more and more usual abrasiveness test (ABR index) has been developed by the Laboratoire Central des Ponts et Chausséss, Paris, the LCPC [8]. The LCPC test is recommended by the DAUB recommendations for the selection of tunnel boring machines [9] for the evaluation of loose ground.…”

Section: Wear and Abrasivenessmentioning

confidence: 99%

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The determination of performance‐ and payment‐relevant parameters in TBM tunnelling – State of the technology and outlook / Ermittlung leistungs‐ und vergütungsrelevanter Parameter für TVM‐Vortriebe – Stand der Technik und Ausblick

Galler

Handke²,

Nolden³

2014

The success of mechanised tunnelling is greatly influenced by the interactive behaviour of machine and ground. A multitude of published research and practice reports documents the problem of a targeted forecast based on tests and forecasting models [19]. The paper describes the currently used methods of estimating performance-relevant parameters, including current research into the subject of crack propagation in solid rock and developments in disc force measurement on the tunnel boring machine and its forecasting from laboratory tests. IntroductionIn order to determine a theoretical performance forecast for a TBM drive at the design stage, the entire tunnelling process is divided into partial elements and process activities. These include, at the interface to the ground, 1:1 measurements of disc forces and in the future also the minidisc cutting test newly developed at the Montanuniversität Leoben. Final statements to forecast the performance are, however, first possible based on knowledge of the in-situ stress conditions, the prevailing geological and hydrogeological conditions in interaction with the tools used and the tunnel boring machine -in other words, through tests during the construction phase. Performance-relevant parameters in TBM tunnellingState of the technology 2.1 OverviewThe resulting advance rate is determined by the interaction of geological, mechanical and process-technical and construction operational factors. The cutterhead penetration is defined as the average advance into a rock or rock mass for one single rotation of the cutterhead [1]. The penetration in collaboration with the disc track spacing greatly determines the formation of fractures in the rock while boring solid rock. With decreasing size of the chips and increasing fines content in the muck, the danger of wear and clogging increase, and this is worsened by insufficient material transport. In cohesive soils, cutting wheels with a EinleitungZur Ermittlung der theoretischen Leistungsprognose eines TVM-Vortriebs im Planungsstadium wird der gesamte Vortriebsprozess in Teilelemente und Prozessabläufe untergliedert. Hierzu gehören an der Schnittstelle zum Baugrund auch 1:1-Diskenkraftmessungen sowie zukünftig u. U. ein an der Montanuniversität Leoben neu entwickelter Minidiskenschneidversuch. Endgültige Aussagen zur Leistungsprognose sind i.d.R. aber erst auf Basis der in situ vorherrschenden Spannungsverhältnisse, der anstehenden geologischen und hydrogeologischen Verhältnisse in Wechselwirkung mit dem eingesetzten Werkzeug, der Tunnelvortriebsmaschine -also durch Versuche während der Bauausführung -möglich. R. Galler/D. Handke/M. Nolden · The determination of performance-and payment-relevant parameters in TBM tunnelling -State of the technology and outlook small degree of opening tend to clog. With the danger of clogging, the wear also increases, and is worsened by insufficient material transport from the face.

“…In the quoted standard, only the test apparatus and the test procedure associated with it are specified; there is no treatment of the test preparation. A description of the test for rock can be found in [7]; a detailed procedure for soil has been proposed in [12] [13] [14], and in the meantime a multitude of further investigations have been carried out in soil and rock, in the course of which this test became better established as a method for the characterisation and classification of soil and rock.…”

Section: Untersuchung Der Abrasivitätmentioning

confidence: 99%

Classification of the abrasiveness of soil and rock

Thuro

Käsling

2009

The abrasiveness of soil and rock is a determining factor for tool wear in all processes of rock excavation above and below ground, for example drilling, cutting and excavating. Although this is highly cost-relevant, no classification scheme has yet been produced, with which soil and rock can be classified according to their abrasiveness and wearing effect. Comparative investigations using three methods of determining abrasiveness were used to produce a proposal for the classification of rock material. Although further series of investigations still have to be performed, a classification scheme has been produced, which is already in practical use and could be of use in future projects.