Time filter

Source Type

Volkmann G.M.,DYWIDAG Systems International GmbH | Schubert W.,Graz University of Technology
14th Australasian Tunnelling Conference 2011: Development of Underground Space, Proceedings | Year: 2011

Pipe umbrella systems have effectively been used as an additional support system in the working area in weak ground conditions during the last decades. Thus, a considerable number of applications accounts in urban tunnelling with shallow overburden. However, this support system is also successfully used when a tunnel alignment crosses fault zones, sediments, moraines or talus with overburdens from shallow to deep. The pipe umbrella support system itself is termed differently worldwide - synonyms are canopy tube umbrella method, umbrella arch method, or long fore-poling method. One main reason for the increase in application is that this support system closes cost-effectively the gap between reasonable, normal supported tunnels and tunnels supported with more expensive special techniques like horizontal jet-grouting or ground freezing. By using this system, many projects can be built more cost effective without decreasing the common level of safety. The pipe umbrella construction method is pretty young, so the knowledge about this system has been intensely researched in the last decade. This led to an enormous increase in understanding the interaction between support system and surrounding ground, the mode of action, and the important details for construction. Pipe umbrella support systems are applied in difficult ground conditions, so a special developed measurement arrangement was used to observe deformations ahead of the working face during tunnelling. The evaluation of collected data sets identified that cased-drilling systems have clear advantages compared to predrilling systems during the installation process in weak ground conditions. This may become important depending on project requirements, so this difference must be considered in design as well as in the tender document specifications. Source

Volkmann G.M.,DYWIDAG Systems International GmbH | Schubert W.,University of Graz
Rock Mechanics in Civil and Environmental Engineering - Proceedings of the European Rock Mechanics Symposium, EUROCK 2010 | Year: 2010

Pipe umbrella support systems are used in weak ground conditions. The main reason for using this system is the supporting effect in the working area, which leads to safe construction conditions. Due to the complex stress transfer processes around the heading there is still a lack of knowledge regarding this system. Based on high quality measurements in the past years back-calculations of in-situ data were performed. Exemplary results of these back-calculations will be shown and typical characteristics described. By using this knowledge, calculations during design can be performed that define the structural properties for the supporting pipes and changes in the load redistribution. © 2010 Taylor & Francis Group. Source

Islam S.,DYWIDAG Systems International GmbH
SHMII 2015 - 7th International Conference on Structural Health Monitoring of Intelligent Infrastructure | Year: 2015

Monitoring and evaluating the structures have become more significant than ever. Pre-stressing steel is an important part of the structure where it is installed. Unfortunately there are limited testing methods available to assess the force in the pre-stressing steel. High cost, complicated equipment and limitation of space often prevent these methods from being implemented. DYNA Force® sensors have been developed to measure the force in the pre-stressing steel during construction and at any time during the lifetime of the structure. These sensors are manufactured based on the magneto-elastic properties of ferrous material. A readout unit is designed to magnetically energize the steel through the sensor and measure the response of the steel to a direct force reading. The force reading can be collected manually, automatically and also remotely. They can be used for bare, epoxy-coated, galvanized and greased-sheathed steel in bonded, un-bonded, grouted or un-grouted length of the tendon/anchor. It has received attention in terms of accuracy, its performance, ease in installation, durability, and cost effectiveness. It has been used in over sixty projects in the USA, Canada and overseas. Its application in bridges, buildings, retaining walls and dam structures is discussed. © 2015, International Society for Structural Health Monitoring of Intelligent Infrastructure, ISHMII. All rights reserved. Source

DYWIDAG Systems International GmbH | Date: 2015-08-04

Building materials of metal, namely rock and soil anchor systems; goods of metal, namely, construction tension elements of steel, namely post tensioning systems for piles, ground and rock anchors; anchoring elements of metal, namely, anchoring bolts, screws, sleeves, shims; cladding tubes of metal. Mechanical apparatus and machine-like tools for structural and civil engineering, namely, mechanical and hydraulic presses for anchoring of support structures for excavations; apparatus for insertion of rods and strands, and screwing devices, namely horizontal and vertical uncoilers; mechanical apparatus for tensioning of pre-stressing elements, namely hydraulic jacks; mechanical apparatus for treating and injecting settable and/or anticorrosive materials, namely post grouting machines; drilling machines. Building materials not of metal, namely rock and soil anchor systems and anchoring elements, namely, anchoring bolts of plastic; tension elements, namely post tensioning systems of fiber composites and of plastic for soil and rock anchors; anchoring elements, namely, anchoring bolts of plastic; rigid building materials, namely cladding tubes of plastic; settable and/or anti-corrosive materials for injection into construction elements, namely, mortars with an artificial resin and/or cement base. Building construction; Structural and civil engineering, namely, installing supporting elements in construction works, installing and tensioning pre-stressing elements and treating and injecting settable and/or anti-corrosive materials; post-tensioned construction in the nature of installation of subterraneous curtains and posts, fixing ground anchors and rock anchors, mounting tension and compression piles, ground and rock anchors and rock and ground spikes made of metal or fiber composites; maintenance and repair of domestic technique equipment, namely post tensioning systems; excavation services; earthworks; rental of machines, apparatus and tools for building construction.

For drilling holes in soil or rock material and for fixing an anchor in a borehole, an expanding element fixed to a drill or anchor rod and a spreading element are introduced with the rod into the soil or rock material, the spreading element is expanded to butt against the wall of the borehole after completion thereof by the rod. The expanding element being retracted into the spreading element. The rod is secured by an anchor plate on an outer side of the borehole. After expansion of the spreading element, the rod is subjected to a rotary movement in the direction of the interior of the borehole until there is abutment with the interior of the borehole. The rod is fixed to the outside of the borehole by bracing the anchor plate by means of a nut.

Discover hidden collaborations