1,720,968 research outputs found
Influence of the soil conditioning additives on the adhesion problems in clayey soils and feasibility study for soil conditioning of rock masses for EPB tunnelling
No full textThe aim of this thesis is the demonstration that tunnelling with EPB technology can be applied also in geological conditions considered out by the common applications range as in rock masses, and that the proper combination of conditioning additives can face some common problems that can occur in difficult soils for EPB tunnelling as clayey soils.
In the first chapter a general overview of the EPB technology is carried out describing the most important technical features, the working principle and the common application fields of this kind of TBM. The second part of this chapter is an overview of the soil conditioning techniques and of the soil conditioning additives used in EPB tunnelling.
The second chapter is the resume of the technical literature review about conditioned soil testing. This literature analysis has been carried out studying foe each soil conditioning research topic the commonly used tests and the different tests proposed by many authors of different technical universities from all over the world. This research has been considered necessary to understand the state of art of soil conditioning testing in order to perform a research able to fill some research fields non yet deeply studied.
The third chapter is the descriptions of all the soil conditioning test that can be performed in the Tunnel and Underground Space Center laboratory of Politecnico di Torino where the tests reported in this research has been carried out with both commonly used and standardized test procedures, with experimental devices designed during the almost ten years of history of this laboratory and with specific test studied, designed realized and tested during this research.
The fourth chapter is a research carried on with the aim to observe the differences between some commercial soil conditioning additives commonly used for the treatment of clayey soils. The research has been carried out using three different clayey soils and four soil conditioning additives. Four different test procedure has been used to evaluate the behavior of the soil conditioned with the different products. The first tests carried out have been the slump test and the vane shear test in order to assess the proper set of conditioning parameter that allows the change of behavior of the clayey soil in a suitable conditioned muck. To evaluate the influence of the different products on the adhesive features of the conditioned soil two specific test have been studied during this research. The results of this research are described and discussed at the end of the chapter.
In the fifth chapter are reported the tests and the results carried on with the aim to verify the possibility to properly treat the muck of a rock TBM in order to apply the EPB technology also in rock masses. This research has been started studying the possible grain size distribution of the much of a EPB TBM with rock tools by the data collected in technical literature. When assessed a range of grain size distribution considered simulative of the TBM muck, a slump test campaign has been performed for each one of the three geological formations studied. The conditioning parameters assessed with the slump test campaign have then been verified with screw conveyor extraction tests performed with the specific experimental test apparatus realized in Politecnico di Torino with very interesting results. All the test carried out during this research are described and the results are discussed at the end of the chapter
Influence of chemical additives used in EPB tunneling and its management - Wplw dodatkow chemicznych, stosowanych w drazeniu tuneli tarczami zmechanizowanymi TBM tyou EPB
No full textEarth pressure balance tunnelling in rock masses: Laboratory feasibility study of the conditioning process
No full textEarth pressure balance (EPB) shield tunnelling is considered to be an effective tunnelling method when surface settlements must be avoided by controlling face stability and underground water inflow. EPB technology is applied increasingly to the conditioning of rock masses in which the presence of polluting material is foreseen and must be controlled, or when explosive gases from the rock mass must be prevented from entering in the machine. The use of an EPB machine in ‘closed mode' can prevent the dispersion of dangerous materials in the underground environment. This study was performed to evaluate the feasibility of using EPB technology in rock masses and the effectiveness of this tunnelling process in terms of soil conditioning, conditioned soil permeability, pressure transmission on the tunnel face, and the ability to extract the material with a screw conveyor. The research was developed with a set of laboratory tests carried out on three different types of rock masses where tunnelling with EPB machines are planned to be constructed in Italy but the results can be easily applied to similar rock mass types. The tests have been carried out both with slump tests and with a specially constructed screw conveyor extraction device. In the paper the most important results are presented and discusse
Laboratory Tests for EPB Tunnelling in Rock Masses. Feasibility Study
No full textThe EPBS (Earth Pressure Balance Shield) tunnelling is widely used when is necessary to avoid surface settlements by controlling face stability and the underground water income. A growing field of application of this technology is in rock masses where polluting materials are present, or when it is necessary to work with a full bulk chamber to prevent exploding gasses to come inside the tunnel. In fact the particular operative procedure of EPB technology, using the machine in "closed mode", can avoid the dispersion of the dangerous materials in the underground environment. The presented research has been carried out in order to evaluate the possibility to use the EPB technology in rock masses with an effective tunneling process in terms of soil conditioning, conditioned soil permeability, pressure transmission on the tunnel face and possibility to extract the material with screw conveyor, and the obtained results are described and discusse
Soil Conditioning for EPB Mechanized Tunnelling: comparison of laboratory tests and job site results
No full textLaboratory tests are of key importance for a correct design of an EPB machine tunnel excavation. Some laboratory test results achieved on some soil sample collected in different jobsite are described and discussed in comparison with the soil conditioning data really used in the job sit
Study of the permeability of foam conditioned soil with laboratory tests
No full textThe results of permebility test on conditioned soil are presented and discusse
Effect of soil conditioning on tool wear in soft ground tunnelling using shield machines تاثير فرآيري خاک ت سًظ آب ي ف مً برريي ميسان سایش ابسارحفاري با ماشيى اُي
No full textLaboratory tests on soil conditioning of clayey soil
No full textThe paper presents the results of soil conitioning tests on cla
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