- Lifting anchor used in the anchor, should be strictly in accordance with the design of the production, and do a good job of hidden engineering records, the use of not allowed to overload;
- Ground anchor pit should be dug into a rectangular trapezoidal shape, slope and vertical angle of 15 degrees is appropriate. The depth of the anchor is determined according to the general situation of the site.
- The angle between the tow rope and the horizontal plane is generally less than 30 degrees, and the anchoring point of the anchor pit (ie, the rope is exposed to the ground after passing through the soil). The depth of the front pit is 2.5 times and the foundation pit is within 2 meters. Trench, cable, underground pipes and other structures and temporary trenching;
- There should be no water around the anchor;
- The anchor is not allowed to be placed along the embedded part.
1. Good selection of quality ground anchor steel
In the construction of greenhouses, the anchor should be laid once, for many years to use. Ground anchor steel embedded in a section of the soil, exposed to the outside of a section, easy to rust, so the anchor used to produce the anchor must be better quality, durability, no rust. In the survey found that farmers have not been buried in the earth anchor, it has been rusty, it will obviously reduce the service life. Therefore, the reporter suggested to build shanty households, we must use high quality anchor anchor.
2. Pay attention to the depth of the pit
The anchor is not firmly fixed, the key to see how deep the anchor. Obviously the more shallow the laying of anchors, the less solid, the more likely to be pulled out. Reporters survey found that the new greenhouses after the completion of the wall in the east and west walls of the two anchors buried at the soil, mostly from the wall rolling down the loose soil. Many farmers in place to lay anchors, although the depth enough, but because of the loose soil layer, not easy to compaction, which led to the anchor is not solid. In this, the reporter suggested that the depth of buried anchor should reach at least half a meter, and must be hard solid soil layer, if the soil loose, can be taken first embedded part of the anchor, and then water Shen real, and then fill compaction .
3. Before use the ground anchor, placed a waste column, strengthen the firmness.
In order to further improve the anchorage of the anchor, it is suggested that before the laying of the ground anchor, a waste column should be laid horizontally on the inside of the ground anchor so that the anchor wire is attached to the column , Separated from the shed wall. This approach also facilitates the use of tightening machines to connect the wire to the ground anchor line.
Steel sheet-pilings are one of the most common types of quay walls used in the construction of ports and harbors facilities, especially for berths of small crafts which have small dimensions and capacity. Due to the growing market of marine traffic around the world, an increasing number of these berths are required to be upgraded to meet the requirements of permanently growing dimensions and capacity of vessels. Several methods can be used to increase the load-carrying capacity of steel sheet-piling walls. The use of additional anchored tie rods grouted into the backfill soil and arranged along the exposed wall height is one of the most appropriate solutions adopted for rehabilitation and upgrading of the existing quay wall.
Generally, quay walls play a crucial role in the operational capacity of ports, marinas, shipyards and other waterside facilities. Steel sheet-pilings are one of the most common types of quay walls used in port construction. They are widely used in the construction of container and dry-bulk terminal, as well as for sea walls and reclamation projects where a fill is needed seaward of the existing shore and for marinas and other structures where deep water is needed directly at the shore.
Stability of sheet-piling wall depends on pressures excreted on its faces. They include the overturning, that results from active earth pressure; unbalanced water, acting upon the inner face of the wall and the passive pressure, acting on the wall’s stability. In many cases, due to the growing number and size of vessels, there is increasing pressure to upgrade the existing berths that provide higher capacity to the existing sheet pile wall. As a result of upgrading the existing facilities through deepening the quay wall, rehabilitation is required to accommodate these larger vessels. Under these new serviceability conditions, the sheet-piling quay wall should be strengthened to ensure an adequate factor of the wall’s safety against soil collapse and/or structural over-stressing. These are several possible failure mechanisms of grouted anchors. These are usually caused by excessive static loading of an anchor. Excessive loads can be related to: tension placed in the anchor during load testing or at lock-off, excavation sequence, surcharge by construction materials or equipment, construction of adjacent structures or a combination of these causes. Ground anchor failure mechanisms may involve the steel tendon, ground mass, ground-grout and grout-tendon zones (Sabatini et al., 1999).
Several methods can be used to increase the load-carrying capacity of the wall. The use of additional anchored tie rods grouting to the backfill soil and arranged along the exposed wall height is one of the most practical solutions adopted for rehabilitation and upgrading of the existing quay wall (Ebeling et al., 2002 and Strom and Ebeling, 2001).
(This article comes from docin editor released)