An Introduction to Trenchless Technology Piping (+Türkçe Özet)

The first reason for the preparation of this book is to share recent developments experienced in underground infrastructure technology with readers. It is the fact that innovative methods are becoming main route in underground piping constructions, renevations and rehabilitations. The second reason is to give awareness of trenchless technology in civil engineering and environmental engineering societies and world communities as well as the Turkish community. The development of new equipment and method and increased level of equipment sophistication and capabilities are driving forces of trenchless technology. A safe and successful trenchless project depends on skills, training and experience of operators, field personal and project inspectors. This book will be of use for all parties in a trenchless project as it provides planning, design, construction, inspection and project management concepts

Objectivation of the Necessity of Structural and Parametric Synthesis of the Hydraulic Drive Of Geokhod

This article considers main systems of a prototype model of geokhod as well as their technical specifications. There are ways distinguished of decreasing the dimensions and the mass of elements of the hydraulic drive. As an optimization tool of structural and parametric parameters of the prototype model of geokhod, there is SimHydraulic simulation considered

Advancing Control for Shield Tunneling Machine by Backstepping Design with LuGre Friction Model

Shield tunneling machine is widely applied for underground tunnel construction. The shield machine is a complex machine with large momentum and ultralow advancing speed. The working condition underground is rather complicated and unpredictable, and brings big trouble in controlling the advancing speed. This paper focused on the advancing motion control on desired tunnel axis. A three-state dynamic model was established with considering unknown front face earth pressure force and unknown friction force. LuGre friction model was introduced to describe the friction force. Backstepping design was then proposed to make tracking error converge to zero. To have a comparison study, controller without LuGre model was designed. Tracking simulations of speed regulations and simulations when front face earth pressure changed were carried out to show the transient performances of the proposed controller. The results indicated that the controller had good tracking performance even under changing geological conditions. Experiments of speed regulations were carried out to have validations of the controllers

Influence of material conditioning on tools wear of EPBS machines using different laboratory test

Underground construction in urban areas that need more efficient transportation systems, energy and water supplies is a very challenging task, due to the complexity of the work itself and because surface disturbances and subsidences require to be minimized. In order to face the challenge and allow the excavation of tunnels even with low overburdens, Earth Pressure Balance Shields (EPBS) technology has been increasingly used in the recent years. EPBS is a type of tunnel boring machine (TBM) with earth pressure support. By transforming the excavated material into a soft paste that has plastic properties to be used as support medium, it is possible to balance the pressure conditions at the tunnel face allowing minimum settlement. In addition, uncontrolled inflow of soil and water into the machine is avoided and tunnelling process becomes more effective. In order to better understand soil behaviour and improve the performance of the EPBS machine, two variables are studied: soil conditioning and tools wear. During excavation with EPB machines the correct soil conditioning is a very important parameter to be controlled. For this reason, it is critical to perform preliminary tests with different conditioning agents in order to determine the most suitable reference dosage for an excavation project. Currently, soil conditioning is evaluated by performing slump tests and plasticity and homogeneity checks of the dough at laboratory scale. There is also the Extraction Test used to evaluate material extraction that is one of the most realistic tests to know the behaviour that soil could develop during excavation process. On the other hand, a very important but still less studied variable is the wear of EPBS metal parts like excavation tools, rotating head, shield and screw conveyor. Wear leads to a reduction in working yield due to the mentioned machine components lose their optimum properties and have to be replaced; consequently, downtime is required in order to execute proper maintenance, which is difficult and dangerous. Many aspects play key roles in the wear process like excavated medium, water content, applied pressure, soil conditioning and type of metal used for machine tools manufacturing. In fact, rocks and soil excavated during EPB work can be composed from any kind of minerals. Hard minerals increase the wear phenomenon that concerns all parts of the machine where there is friction between metallic part and the medium. For this reason, study of wear phenomenon is an extremely important issue for new projects with EPB excavation technology. Therefore, the objective of this work is to study of the influence of soil conditioning on tools wear and the relationship of the main factors associated to this phenomenon. In order to accomplish this goal, about 26150 kg of different soils were studied using 4 different wear test methods. These tests were based on the application of a test methodology already used in the Tunnels and Underground Works Laboratory of Politecnico di Torino and other new methodologies and equipment, developed with the aim of deepening the study of wear taking into account several variables that concern the construction of tunnels. Each methodology implemented has different benefits, limitations and scopes, but provides congruent technical results. Finally, prediction indexes were proposed in order to evaluate tool wear phenomenon and compare the effects of different soil conditioning. As a result, better decisions are made when choosing the ideal conditioning for EPB tunnelling, maximizing projects effectiveness and success

Web-based Visualisation for Look-Ahead Ground Imaging in Tunnel Boring Machines

Tunnel Boring Machines (TBMs) are large multi-million pound machines used to excavate underground tunnels. In order to make best use of the high-speed performance of a TBM and guarantee the safety of excavation, it is important to know the local geology, structures and ground properties ahead of the TBM cutter head, especially in complex geological conditions (e.g. karst caves). By working with experienced geophysical experts, tunnelling engineers/consultants and TBM manufacturers, we propose a novel web-based visualisation platform to help TBM operators efficiently manage, process and visualise the TBM parameters, the geology map created by geo-experts based on boreholes, and especially the imaging data captured by an on-board ground imaging system for "seeing through" the ground beyond the excavation surface. Informative visualisation interfaces were designed to facilitate interpretation of the imaging data and adding annotation by users; algorithms were developed for automatic detection of features and probable events by fusion of radar and seismic imaging data; and a back-end database was designed to store all such relevant information for supporting more advanced interpretation in the future. The web-based architecture not only allows the visualisation platform to be directly linked to on-board sensors (e.g. ground penetrating radars, seismic sensors), but also allows users away from the job site to access the captured data using a standard web browser, enabling a collaborative interpretation process. The data processing, management and visualisation platform presented in this paper is flexible with respect to different imaging sensors and modalities, so it is highly adaptable for any other ground imaging systems for tunnel geology inspection, underground utility surveys, etc

Advanced Underground Space Technology

The recent development of underground space technology makes underground space a potential and feasible solution to climate change, energy shortages, the growing population, and the demands on urban space. Advances in material science, information technology, and computer science incorporating traditional geotechnical engineering have been extensively applied to sustainable and resilient underground space applications. The aim of this Special Issue, entitled “Advanced Underground Space Technology”, is to gather original fundamental and applied research related to the design, construction, and maintenance of underground space

Really large hadron collider working group summary

A summary is presented of preliminary studies of three 100 TeV center-of-mass hadron colliders made with magnets of different field strengths, 1.8T, 9.5T and 12.6T. Descriptions of the machines, and some of the major and most challenging subsystems, are presented, along with parameter lists and the major issues for future study