U type sheet pile: water conservancy construction accomplish much

Anti-corrosion, strong stability, from the river crossed to the sea

U type sheet piles adopt a unique variable cross-section structure design, increase the section height, increase the cross-section resistance to bending moment, but also increase the cross-section width. From the analysis of structural mechanics principle, the stress characteristics and the I-shaped force characteristics are the same, have good bending resistance, and are widely used in inland river. As we all know, sea storms, corrosive seawater is strong, commonly used in offshore engineering embankment pile corrosion resistance is poor, and investment is higher than the precast concrete sheet pile. The design of U type precast concrete piles is taking into account the retaining, corrosion resistance, construction speed and other characteristics, both the characteristics of steel sheet pile, but also to overcome the corrosion of steel sheet pile problem, and stability, and can adapt to more complex Construction condition of sea area. U type sheet pile construction time is short, mechanized construction, significant savings in labor. It changes the traditional construction of water conservancy project, the construction speed is slow, the construction of high labor costs, after forming the quality of instability and other shortcomings, safe, beautiful, reliable and does not require post-maintenance. From the whole project quality, the factory mass production, the quality assurance system can effectively guarantee product quality.

Compared with the traditional method, U type sheet pile has obvious competitive power

In addition, U type sheet pile than the traditional riprap dam greatly saves the cost. Because of the geographical reasons, the stones used in the construction are all from Zhejiang, Jiangsu and other places around Shanghai. With the protection of ecological environment and the promotion of resource saving, Stones and other non-renewable resources to reduce the amount of exploitation, the price of natural rise. With the social development, other costs are also increasing year by year, only a human cost this year than last year increased by 40%, the traditional construction of the dam requires a lot of human resources, greatly increasing the project cost. Although the initial investment is not much difference, but the traditional method of construction cost is much higher than the overall construction cost of U type sheet pile, with the passage of time, gravel resources increasingly scarce, U type sheet pile cost advantage will Unmistakably.

The materials used for lattice cofferdam

The lattice of lattice cofferdam is composed of two kinds of materials: steel sheet pile shell and inner packing. Only when the filler and the sheet pile wall act together, the lattice body is stable, so the choice of grid pile and packing Of the stability is very important.

Steel sheet pile

In the lattice structure, the bending strength in the longitudinal direction of the sheet pile is not the main one, and the lateral tensile strength of the sheet pile should be taken into account. So the lattice body usually adopts the straight web sheet pile. The allowable deflection angle between the lattice piles is generally 10 °, the length of sheet piles produced by each country is usually less than 25m. For the high lattice, the piling of the sheet piles is required for construction. The piles can be reused 3-4 times, The intensity of the sheet pile locking hole may be reduced, subject to re-determine the test, the high head grid cofferdam is appropriate to use the new sheet pile. Grid-shaped cofferdam at the intersection of lattice piles wall to use a special connection pile, connecting pile table T-shaped, Y-shaped and three-shaped, usually by the standard straight abdominal sheet pile riveting or welding, Welding quality of the connection pile is generally not easy to guarantee, should be in the stone manufacturing, strict quality control. For high and medium lattice should use riveting pile.

Cell packing

The general requirement for internal packing is that the filler must have high shear strength and should be incompressible. Fillers can gravity drainage, that is, the filler can rely on the gravity flow of water through the drainage hole to meet the drainage requirements. Resistant to erosion. With a certain anti-sliding bulk density. As far as possible, the lattice body should be backfilled with good quality earth material. It is usually economical to select the packing material near the cofferdam. Sand gravel and coarse sand group is the appropriate grid packing, in order to avoid fine grain through the sheet piling locking gap and drainage are also lost, usually control the filling diameter is less than 0.lmm content of not more than 10%, silt Shear strength Low, intolerant erosion, cofferdam permeate too much.

Eddy current testing method of frequency welded pipe

Eddy current testing principle

The signal generating circuit generates an alternating current to supply the detecting coil; the alternating magnetic field of the coil induces the eddy current in the workpiece, and the eddy current is affected by the material or defect of the test piece; in turn, the impedance of the coil changes; the amplifying circuit first detects the weak detection coil Signal to amplify; then through the signal processing circuit to eliminate interference in the interference factors to identify the “defect” effect; finally show the test results.

Detection system overview

Eddy current testing equipment mainly include: eddy current probe, eddy current testing equipment, auxiliary devices and marking alarm device.

The role of eddy current probe: eddy current induced in the specimen and measure the quality of the specimen with the eddy current signal;

The role of eddy current testing instrument: for the detection coil to provide AC and from the measured to the signal with a large number of information to identify the existence of “defects”;

The role of auxiliary devices: the completion of the workpiece saturation magnetization and other functions;

Precision purification AC power supply: a regulator of high precision, high overload capacity, good reliability, anti-interference ability, high efficiency, fast response, etc., but also can effectively suppress the grid voltage spikes and a variety of noise interference, Anti-electromagnetic interference ability;

Installation Location: Recommended installation in the back of the sink, both sides of a compact round to ensure smooth steel pipe.

Steel Sheet Piling Products

Steel sheet piling is a manufactured construction product with a mechanical connection “interlock” at both ends of the section. These mechanical connections interlock with one another to form a continuous wall of sheet piling. Steel sheet pile applications are typically designed to create a rigid barrier for earth and water, while resisting the lateral pressures of those bending forces. The shape or geometry of a section lends to the structural strength. In addition, the soil in which the section is driven has numerous mechanical properties that can affect the performance.

Steel sheet piling is classified in two construction applications, permanent and temporary. A permanent application is “stay-in-place” where the sheet piling wall is driven and remains in the ground. A temporary application provides access and safety for construction in a confined area. Once the work is completed, the sheet piling is removed.

(This article comes from L.B. Foster Piling editor released)

Bridge Construction: Precautions and Measures of Leakage Prevention and Seepage Prevention of Steel Sheet Piles

  1. The whole process of applying steel sheet pile must be well positioned and strictly controlled the bidirectional verticality so that the pile and the pile have good bite, key.
  2. Pit pumping, the lock is not a mil for the phenomenon of leakage, the use of fiber-rich cotton batten to sew.
  3. The wider the pile can be taken to fill the butter plug with mastic stem water can also be taken with fly ash, saw wood foam, expansion of cofferdam along the cofferdam along the pile surface along the flow direction of the comprehensive treatment method to To stop the purpose of water.

Can also be found in the pumping position after the lath, cotton, linen, etc. in the inside of the sheet pile impaction, or in the leak outside the water throwing ash mixed sawdust at the end. We have done before the time directly in the sewing sawdust at the end of the plug.

Analysis of the common problems in Larsen steel sheet pile construction leasing

Presumably a lot of small partners on the Larsen steel sheet pile construction leasing in the process of some common problems is not a special understanding. Xiaobian to talk about today, Larsen steel sheet pile is a special new steel sheet pile, pile driver and vibration hammer will be pressed into the underground steel sheet pile to form a continuous wall, as a temporary excavation of deep foundation pit , Retaining retaining structure for the project to create a great help, but the steel sheet piling equipment is also a grand project, in the steel sheet pile construction process will encounter this kind of questions.

Larsen steel sheet pile roll and foundation pit arch and ground cracks:

  1. Appearance: selection of Larsen steel sheet pile, excavator earth excavator and transport vehicles located on the ground side of the steel sheet pile, excavation soon found the top of the pile of steel roll, pit soil arch, ground cracks and sinking.
  2. Analysis of the reasons: these steel sheet pile construction are in the soft soil area, the description of the embedded depth can not be, so the pile after the ground sinking, pit soil arch is piping performance. In the excavation operation due to excavators and earthmoving in the steel sheet pile side, an increase of soil on the ground load, resulting in pile top side shift.
  3. Control methods: steel sheet pile embedded depth of the need to determine by the accounting. Excavators and earthmoving vehicles shall not be operated on the foundation pit, and if necessary, the load shall be included in the description to increase the depth of the pile inlay. General Larsen pile construction, the pressure grouting cooperation, adjacent to the steel sheet pile support, base pressure is very good, very good waterproof, base compaction grouting, the thickness of the soil may be. In addition, the connection of the steel sheet pile supporting corner can not be tight, and the appearance of stream sand should be occurred. Therefore, the grouting should be carried out with 3 to 4 grouting. If the groundwater level is high, it is necessary to carry out the cooperation of light well point precipitation.

Production and Application of Plastic Steel Plate Pile With Vinyl Polymer

Polymer plastic sheet pile is a fast, efficient, environmentally friendly form of pile. Light weight, high strength, good sealing performance; corrosion resistance, weather resistance, long service life; reusable and recycling. In line with national advocacy “to plastic strip” “to plastic and wood” of new materials and energy conservation and environmental protection policies. The product adopts industrial mass production, mechanized construction, high efficiency, short construction period (one-thirtieth of the traditional stone dyke construction), low construction cost (two thirds of traditional stone dyke construction, 1/2 of steel sheet pile construction ).

Polymer plastic sheet pile to make up for the traditional concrete slope works embankment large amount of time, labor time, labor costs, high cost, difficult to repair and other steel sheet pile corrosion and rust, not environmental protection, cost of high cost. Can be widely used in irrigation and irrigation channels, canals, small and medium-sized reservoir dam construction and maintenance, embankment bank protection; construction of the pit support, slope protection, retaining walls, walls, flower ponds, cut-off walls, , Ground treatment, underground parking, artificial lake shore, sewage treatment. Traffic engineering roadbed protection, underground tunnels, culverts, pipeline laying, road construction, port and dock construction. Flood prevention and mitigation of flood control projects, dam heightening, anti-landslip, anti-leakage, anti-debris flow, wind and sand. Marine development of the embankment around the building, anti-wave wall, aquaculture, saline base breeding base Wai construction areas.

At present, polymer plastic sheet pile has been widely used in Canada, the United States, Britain, Germany, Poland and other developed countries.

Trench Sheet Extractor

Trench sheet extractors are used for removing trench sheets from an excavation one at a time through the pre-drilled hole in the end of the trench sheet, reducing the risk of damage during removal.

There are two types. The standard one has a hinged jaw arrangement with a pin that locates through the pre-drilled hole in the end of the sheet & the other is a quick release one that allows single operation lifting with a rope attached to release the sheet from ground level.

  • Standard = s.w.l of 5 Tonne
  • Quick release = s.w.l. of 2 Tonne

(This article comes from Pro Mech Ground Support Systems editor released)

Construction Technology of Steel Tie Rod

The construction steel tie rod relates to a prestressing tension device, in particular, high strength and large diameter relative to other types of tie rods. Through a special heat treatment process, to achieve a good comprehensive mechanical properties. It is fixed with the pin and the connecting pieces at both ends, and the auxiliary tension and the thread are loosened through the sheath.

The technical scheme adopted is:

  1. Heat treatment technology;
  2. Pin positioning technology;
  3. Pre – tightening technology of anti – loosening tooling;
  4. Threaded connection, adjusting sleeve to achieve structural tensioning technology;
  5. End forging, upsetting technology.

Because of its stable performance, the high-grade steel tie rods are widely used in shipyard construction, bridges and construction fields. But also by the application of prestressing, can achieve a large span, reduce the weight of the structure, to the combination of architecture and the beauty.

Functioning of Tie Rods

Tie rod is a long strong rod with bolts or tie bolts at both the end. This rod holds the three major engine components i.e. Cylinder block or entablature, “A” frame, and crankcase in compression and transmits the firing load to the bedplate.

The tie rods are fitted through the above mentioned components and are hydraulically tightened so that the whole engine can be held in compression.

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Tie rods are placed as close to the centreline of the crankshaft of the engine to minimise the bending movement in the transverse girder.

(This article comes from MarineInsight editor released)