A Rapid Experimental Procedure to Assess Environmental Compatibility of Conditioning Mixtures Used in TBM-EPB Technology

Bavasso, Irene; Vilardi, Giorgio; Sebastiani, Diego; Giulio, A. Di; Felice, Marta Di; Biase, Andrea Di; Miliziano, S.; Palma, Luca Di

doi:10.3390/app10124138

Cited by 2 publications

(3 citation statements)

References 31 publications

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“…There is a group of scientists [ 30 , 31 , 32 , 33 ] that tries to improve the process of sand–lime brick production or conducts research works aimed at improving the physical and mechanical properties of the products in question. Several variants of the proposed changes are presented below, although not all of them guarantee the receipt of the so-called natural product, which is silicate.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Organic Compounds on the Special Properties and the Microstructure of Autoclaved Brick

Dachowski

Stępień

2023

IJERPH

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After a long decomposition process, organic matter turns into humic substances. In humus, carbon dioxide (CO2) bound in photosynthesis is brought back to the soil, where it should be used by its ecosystem. This is important because similar relationships are found in modern concretes and concretes designed with the use of geochemical modeling (possibility of the C-S-H phase for storing harmful substances). The aim of the article was to investigate the possibility of using humus (Humus Active-HA) and vermicompost (Biohumus Extra Universal-BEU), i.e., organic matter resulting from a long process of biological decomposition in the production of autoclaved bricks containing only ecological materials, i.e., sand, lime, and water. Tests of compressive strength, density, microstructure based on SEM, XRD, and micro-CT analysis were performed. The results of the research indicate that humus and vermicompost can be successfully used in their production. The paper compares traditional products and products made of raw material mass containing 3%, 7%, and 11% of humus and vermicompost, using the apparatus of mathematical experiment planning. Compressive strength, volumetric density, water absorption, and wicking, porosity, and material microstructure were tested. The best results were obtained for samples with the addition of 7% humus and 3% vermicompost. The compressive strength increased to 42.04 MPa (compared to standard bricks, whose strength is 15–20 MPa), and the bulk density increased by about 55%, to the value of 2.11 kg/dm3, which indicates the densification of the material’s microstructure. They were characterized by the highest compressive strength, moderate water absorption, and a high proportion of closed pores in the sample.

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Section: Introductionmentioning

confidence: 99%

“…There was an article [ 33 ] devoted to TBM-EPB tunneling technology. In tunneling machines (TBM) using the equivalent pressure method, there is a problem of biodegradation of the mixtures used.…”

Section: Introductionmentioning

confidence: 99%

Effect of Organic Compounds on the Special Properties and the Microstructure of Autoclaved Brick

Dachowski

Stępień

2023

IJERPH

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“…The versatility of an earth pressure balance (EPB) shield has led it to become the most popular type of tunnel boring machine (TBM) for use in various ground conditions around the world [1,2]. During tunnelling, an EPB shield uses the excavated soil to fill the working chamber and stabilize the tunnel face.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of EPB Shield Tunnelling with TBM Operational Condition Control Using Coupled DEM–FDM

Lee

Choi

et al. 2021

Applied Sciences

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This study demonstrates a three-dimensional numerical simulation of earth pressure balance (EPB) shield tunnelling using a coupled discrete element method (DEM) and a finite difference method (FDM). The analysis adopted the actual size of a spoke-type EPB shield tunnel boring machine (TBM) consisting of a cutter head with cutting tools, working chamber, screw conveyor, and shield. For the coupled model to reproduce the in situ ground condition, the ground formation was generated partially using the DEM (for the limited domain influenced by excavation), with the rest of the domain being composed of FDM grids. In the DEM domain, contact parameters of particles were calibrated via a series of large-scale triaxial test analyses. The model simulated tunnelling as the TBM operational conditions were controlled. The penetration rate and the rotational speed of the screw conveyor were automatically adjusted as the TBM advanced to prevent the generation of excessive or insufficient torque, thrust force, or chamber pressure. Accordingly, these parameters were maintained consistently around their set operational ranges during excavation. The simulation results show that the proposed numerical model based on DEM–FDM coupling could reasonably simulate EPB driving while considering the TBM operational conditions.

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A Rapid Experimental Procedure to Assess Environmental Compatibility of Conditioning Mixtures Used in TBM-EPB Technology

Cited by 2 publications

References 31 publications

Effect of Organic Compounds on the Special Properties and the Microstructure of Autoclaved Brick

Effect of Organic Compounds on the Special Properties and the Microstructure of Autoclaved Brick

Numerical Simulation of EPB Shield Tunnelling with TBM Operational Condition Control Using Coupled DEM–FDM

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