|
|
Thus, besides the creation of an overcut and the lubrication and support of the associated annular gap from DN/ID 800 (32 in), intermediate jacking stations can be installed from DN/ID 500 (20 in) for sectional or cyclical jacking of the whole pipe string in order to reduce the jacking force. New developments in past years have aimed at, among other targets, reducing the individual forces connected with jacking still further and making them more calculable. … |
||||
|
|
May 04, 2020
|
||||
|
|
|
||||
|
|
May 04, 2020
|
||||
|
|
|
||||
|
|
May 04, 2020
|
||||
|
|
May 04, 2020
|
||||
|
|
May 04, 2020 |
||||
|
|
May 04, 2020
|
||||
|
|
|
||||
|
|
May 04, 2020 Decide for yourself in the following table whether obstacles listed in the left column can be removed or not removed during tunneling. You will find the solution on the following page. (Table: Classification of obstacles into the category removable or non-removable [FI-Steina]) |
||||
|
|
May 04, 2020
|
||||
|
|
May 04, 2020 (Image: Attention!) Obstacles can be noticed, for instance, by:
|
||||
|
|
May 04, 2020
|
||||
|
|
|
||||
|
|
May 04, 2020 (Image: Removal of obstacles by destruction and/or removal from an auxiliary pit) |
||||
|
|
|
||||
|
|
May 04, 2020 |
||||
|
|
Jan 31, 2023 Micro tunnelling refers to unmanned, remote-controlled methods for jacking pipes. This module covers the various methods, in particular, micro tunnelling with hydraulic, pneumatic, auger and scraper conveyance and soil displacement. The focus is on removal and processing the spoil, drive variants of the cutting head, cutting head design, application in groundwater, measures to reduce jacking forces and measures to remove obstacles. After completion of this module, you will have a sound knowledge of:
|
||||
|
|
(Image: Open cut trench working space) The trench width has always been the subject of discussions due to its impact on the economic efficiency and the quality of pipe installation. The trench width should be dimensioned in such a way as to provide sufficient working space around the pipe. The working space is considered to be the area at the base of the trench measuring from the outside edges of the pipe to the inside edge of the shoring or the trench … |
||||
|
|
(Image: Question). What kind of failures or problems are visible on the images? (Image: Inadequate working space at the side of the pipe (no arrow)) (Image: Inadequate working space at the side of the pipe – Proper compaction is impossible) |
||||
|
|
The minimum trench width defines the minimum working space in the trench needed to enable proper compaction of the haunch zone and of the embedment. A definition of the minimum trench width can be found for example in the European standard [DINEN1610:1997]. The minimum trench width is a function of both the nominal pipe size and the trench depth. (Image: Minimum trench width subject to the nominal pipe size) (Image: Minimum trench width subject to the … |
||||
|
|
The abbreviation for the nominal size of the pipe is DN (Diameter Nominal) or ID (Internal Diameter). It defines the parameter for circular cross sections in millimetres (without specifying the unit mm). The nominal size approximately corresponds to the clear diameter. (Image: Attention!) The minimum trench width is determined solely by the OD = outside diameter of the pipe. Non-circular cross sections are classified into DN groups with the help of … |
||||
|
|
Standards, specifications and installation guidelines used in the United States are specific and unique for each pipe material, therefore, unlike the European standards, there is no general approach documented in one single standard related to minimum trench width calculation. As a result, the most common practice in the US is for the engineers and contractors to follow the specifications imposed by the pipe manufacturer, or the specifications prescribed … |
||||
|
|
11094 search results:
