Trench Shuttering & Shoring

Trenches collapse for numerous reasons and excavations should therefore be shored for safety reasons, a trench does not have to be in excess of 1200mm deep to be dangerous particularly if you are bending down or crouching in the excavation in order to joint a pipe or pick up the tape measure you have dropped.

Loose and granular soil is naturally unstable as are most ground types when affected by ground water or inclement weather, trenches that cross disturbed or infill ground are also prone to collapse and vibration from site plant and vehicles can also disturb previously stable ground.

It is therefore necessary to use a proprietary trenching system such as hydraulic walling frames, trench sheets, trench boxes and drag boxes

Other techniques used for trench safety include battering back the sides of the excavation to a safe working angle and stepping the sides of the dig, though these techniques are usually used on larger projects.

(This article comes from draindomain.com editor released)

Application of Anchoring System in External Insulation of Exterior Wall

At present, in various parts of the promotion and application of a variety of exterior insulation system technology and products in the process of building walls more or less hollowing, cracks or shedding, etc., not only affect the energy efficiency of buildings, but also directly affect To the community’s recognition and application of this technology. Therefore, the external wall insulation reliability and safety issues must be brought to our attention, need to take effective measures to solve.

In order to ensure the external insulation system reliability and security, in the use of adhesive fixed basis, and then through the mechanical anchor reinforcement is necessary. As early as July 1, 2003 implementation of the “expansion of polystyrene board thin plaster external insulation system,” the national standard, the external wall insulation system used in the development of anchors have strict performance requirements, from which it is easy to see the role of anchors.

As we all know, the external wall insulation is a system, it is not by a single category of products. Currently there are two commonly used systems, one kind of bolt with the entire system, the other is connected with the bracket insulation system. Select insulation anchors to be involved in the substrate, the thickness of insulation, insulation materials, as well as system applications. The anchor bolt into the substrate after the main friction, convex combination (mechanical locking), chemical bonding three forces to bear the load. Domestic use is the most after the two. In the European countries, the application of anchors for many years, there are strict standards, such as the use of the substrate, how to plaster layer or finishes in the existing surface insulation layer are provided. China draws on foreign standards, in the relevant provisions of the provisions of more than a certain height of the building through the anchor bolts to connect to the foundation of the above part of the insulation surface must also be used insulation anchor.

On the installation of insulation anchor, there are two main ways. One is a percussive installation, convenient and quick, do not need additional installation tools. The other is screw-in installation, the need to use special installation tools and the appropriate installation techniques. But screw-in mounting can provide higher bearing capacity and safety. In the installation process, will be screwed into the disc inside the insulation cap position (insulation cap and the disc is flat), can be a good way to avoid heat loss. In addition, we have to consider the thickness of the insulation board, but also consider the plaster layer thickness. Because it involves some of the actual installation, installation of anchors must pay attention to playing the hole, the hole must be longer than the length of the insulation anchor. It is worth noting that the installation of the nail and the disc to install separately, first knock down the disc, then nail into. Currently on the market there are already in the design of the screw to play with the role of the safety foot to prevent disc cracking products, nails and discs are nailed together.

From the perspective of the structure of the building, the composite wall insulation system along the wall thickness direction is composed of a variety of different materials, and these have different thermal conductivity of the materials were in different temperature fields, thermal expansion and contraction degree and direction Are not the same, the resulting stress load is very complex. In addition, these materials in different wind and negative pressure field, the force size and direction will change due to changes in the outside world. Therefore, the composite wall insulation system load characteristics of non-linear, three-dimensional, time-varying, if not take feasible measures, problems will inevitably arise. Therefore, the implementation of insulation measures on the building, the increase in the anchor is an essential process, the only way to ensure the system safe and reliable.

Enhancement of steel sheet-piling quay walls using grouted anchors

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. An extensive parametric study through the finite element program, PLAXIS, version 8.2 was carried out to investigate the enhancement of using grouted anchors technique on the load response of sheet-piling quay wall. The influence of sheet-pile wall geometry, grout-ties area, inclination and location, length of grout, dredging depth and backfill soil angle of internal friction to enhance this type of walls are analyzed and the results are presented.

(This article comes from researchgate.net editor released)

Preparation of carbon steel pipe

The raw material of the carbon steel pipe is the round pipe blank. The round pipe embryo is cut by the cutting machine and processed into the billet with the length of about 1 meter, and sent to the furnace to be heated by the conveyer belt. The billet is fed into a furnace and heated at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. After the round tube billet to go through the pressure piercing machine to wear empty. Generally more common punching machine is conical roller punching machine, this punching machine production efficiency, product quality, perforation expansion diameter large, can wear a variety of steel. Perforation, the round tube blank has been three-roll cross-rolling, rolling or extrusion. Squeeze after the tube diameter. Sizing machine through the high-speed rotation of the cone drill bit into the steel embryo drilling, the formation of steel. The inner diameter of the pipe is determined by the outside diameter of the sizing bit. After the steel pipe sizing, into the cooling tower, through the water cooling, the cooling pipe, it is necessary to be straightened. After straightening by the steel pipe sent to the metal detector (or water pressure test) for internal testing. If the pipe has cracks, bubbles and other problems, will be detected. After the quality of steel pipe but also through rigorous manual selection. After the quality inspection of steel pipe, spray paint with the number, size, production lot number. And suspended by the crane into the warehouse.

The advantages and disadvantages of seamless steel pipe

Seamless pipe is a steel, which is hollow, there are many different shapes, to facilitate the selection and use. Seamless steel tube is made of steel ingots or solid tube through the perforation of capillary, and then through a series of industrial production processes to complete. Seamless steel pipe with a hollow section, so that can flow into a lot of water and the like liquid, steel and round steel and other solid steel is not only very hard, King Penguin material is relatively light, is an economic section steel, In many aspects can be used, such as oil drill pipe, car drive shaft, bicycle frame and construction of steel scaffolding. Seamless steel pipe has the advantage of high pressure, good toughness, pipe length and interface less. But the general price of such steel is relatively high, it is easy to corrosion, to be ah yo regular replacement. Seamless steel tube under the same weight light weight. Seamless steel pipe manufacturing ring parts, can improve material utilization, simplify the manufacturing process, saving materials and processing time advantages.

What is SSAW Steel Pipe?

Spiral submerged-arc welding is a process of welding steel pipes, industry insiders always regard SSAW as the spiral submerged-arc welding steel pipe.The SSAW API steel pipe use a narrow billet and produces large diameter pipe, and you can also use the same width billets to produce different diameter pipes. The production cost is lower and it’s process is simple. It is generally used in metal structures, welded pipes for fluid transport, foundation, and some other structures. It is used in power industry, and urban construction. It is one of the China’s 20 key developed products.

The SSAW API steel pipe uses steel coil strip as row materials, after extrusion molding in normal atmospheric temperature, uses the automatic double wires and double side submerged arc welding process to weld steel pipes. The production processes are:

  1. The materials are steel strip, welding flux and welding wire.
  2. Before using, they must go through rigorous physical and chemical tests.
  3. The strip steel should use automatic submerged welding after the steel rolled into steel pipe.
  4. Before molding, the strip goes though flattening, cutting, trimming, planning, surface cleaning, transportation and edge curved processes.
  5. Use electrical contacts to control the cylinder pressure on both sides of the conveyor, that will ensure the strip deliver smoothly.
  6. Use the weld gap control can ensure the weld gaps to meet the welding’s requirements, the wrong side,the diameter, and weld gap should have been controlled strictly.
  7. Outside and the inner welding use the welding machine for single or double wire submerged arc welding.
  8. All the finished welds should go through the online continuous ultrasonic injury check, it will help to get the 100% welds non-destructive testing coverage. If there is any defective, it will alarm automatically and spray markers, production workers can adjust the process parameters at any time, and they can eliminate the defects timely.
  9. Using air plasma cutting machine to cut the steel pipe to single one.
  10. After the steel pipe into single pipes, each batch will go through the strict inspection system and the DNT inspection, to check the welds’ mechanical properties, chemical composition, fusion status, steel surface quality, only all the pipes’ process are qualified, can they be formally put into production.
  11. If there is a continuous acoustic detection marker on the weld, this pipe need manual ultrasonic and X-ray review, if the defective is true, after repairing, it need non-destructive testing again until the defect has been eliminated.

(This article comes from southlandpipe edit released)

What Are Differences Between Spiral Welded Pipe and Longitudinal Welded Pipe?

Differences between spiral welded steel pipe and longitudinal welded pipes are many to be found if you want to use one of them for your project. They are used for different occasions and situations. There are also many types products of steel pipes available that you should know how to choose and how to maintain. With the development of our technology and society, the pipes are already the most suitable material for water or drainage system. They are durable for use and stable even their are hot water or something flowing through.

Spiral pipes are specially treated. They have different advantages and strengths. It has metallurgical process for production of high quality pipeline capacity. For example, when the output of the gantry is equipped with a water cooling system to accelerate cooling, which allows the use of low-alloy components to achieve a particular strength level and low-temperature toughness, thereby improving the weldability of the steel. In the common sense, the coil alloy content is often lower than similar grade steel, which also improves the weldability of the spiral pipe.

Commonly, it is different in the properties of the two types of pipes. The welding process of spiral tube, straight seam steel pipe welding methods are varied from the previous process. So the probability of the presence of welding defects also greatly improved. The straight seam pipe will inevitably be a lot of T-weld. The T-shape weld welding residual stress and weld metal are often in a three-dimensional stress state. So, it can increase the possibility of cracks. For a better utilization, API steel pipe and other steel pipes are inclined to in larger diameter and higher strength. With the increase of pipe diameter, the working efficiency and steel grade increased. The test of spiral welded pipes and longitudinally welded pipes has been done that it indicates that the spiral welded pipe has a high impact toughness. When it comes the applications, the spiral welded pipes are popular.

Processing process of spiral welded steel pipe is strict as well as the test requirement. So no matter it is black steel pipe or API pies, quality and properties are all good. The suppliers and manufacturers are many to be found that if you want to buy one for your project, the size, pattern and shape should be known clearly.

(This article comes from Shanghai Xin Lin editor released)

What is ERW steel pipe and SAW steel pipe

ERW steel pipe

ERW steel pipe is a kind of resistance welded steel pipe, high frequency resistance welding (Electric Resistance Welding, abbreviation

For ERW) ERW is the corresponding English word first letter. Resistance welded steel pipe is divided into AC welded steel pipe and DC welded steel pipe twoforms.

AC welding in accordance with the frequency is divided into low frequency welding, intermediate frequency welding, ultra-IF welding and high frequency welding. High-frequency welding is mainly used for thin-walled steel pipe.

Or ordinary wall thickness of the production, high frequency welding is divided into contact welding and induction welding.

DC welding is generally used for small diameter steel pipe.

Therefore, in general, high-frequency welded pipe is included in the ERW pipe, is a high-frequency welding process to produce an ERW pipe. ERW Longitudinal Welded Pipes (ERW) are the most advanced and economical steel pipes in the field of oil and gas storage and transportation.

SAW steel pipe

SAW steel pipe SAW full name Submerged Arc Welding Steel Pipe It is a submerged arc welding process using steel pipe, the process produces a very high current density, the flux layer to prevent the rapid loss of heat, and its focus on Welding area. Submerged arc welding is widely used in the manufacture of pressure vessels, pipe fittings, beam and column, low pressure fluid, steel structure engineering, with high quality, high production efficiency, no arc and dust.

SAW steel pipe main products are LSAW steel pipe Longitudinally Submerged Arc Welding Steel Pipe straight seam double-sided submerged arc welded steel pipe, which is the use of submerged arc welding technology to produce straight seam steel pipe.

Piling sheet, anchoring equipment and trench shoring system market

The global piling sheet, anchoring equipment, and trench shoring system market is anticipated to witness a cumulative Y-o-Y growth of 5.8% during the period 2016–2024.

The increasing number of infrastructure projects in faster growing economies and the recovering construction sector in relatively mature economies is expected to drive the demand for piling sheets, anchoring equipment, and trench shoring systems globally. An increase in mining exploration and excavation activities in some key geographies such as Canada, South Africa, and India are also likely to fuel demand.

The rising adoption of aluminium trench boxes and the replacement of traditional piling sheet wall structures are some of the key market trends likely to be seen in the next few years.

Market highlights:

  • Sales revenue of global piling sheet is expected to increase at a CAGR of 5.5% during the forecast period.
  • The global anchoring equipment market is expected to expand at a CAGR of 4.7% during the forecast period.
  • Sales revenue of the global trench shoring system market is expected to increase at a CAGR of 3.8% during the forecast period.
  • The cold rolled piling sheet sub segment is expected to witness relatively fast growth in terms of revenues compared to the other piling sheet sub segments.
  • The strand anchor segment will remain the largest segment in the anchoring equipment segment, with an estimated revenue contribution of 46.5% in 2015.
  • The drill hollow bar segment is expected to ramp up in higher revenues compared to the threadbar and helical anchor segment.
  • In the trench shoring system segment, the slide rail shoring system will account for up to 42 % by 2024 end compared to other segments.
  • The pipe grabber segment is expected to expand at a higher rate compared to the pipe puller segment during the forecast period.

On the basis of the region, the Asia Pacific held the dominant market share of 37.3% in terms of value in 2015. The Middle East & Africa and Latin America markets are expected to witness thriving demand during the forecast period characterised by an increasing growth of the infrastructure sector in these regions. The U.S market is expected to witness moderate growth in terms of revenue during the forecast period. Europe will witness sluggish growth due to a gradual economic recovery during the 2016–2024 period; however, the market is expected to grow after 2019.

The Asia Pacific piling sheet market is expected to witness the highest CAGR of 6.7% in terms of value. The Asia pacific trench shoring system market is expected to exhibit a strong growth of 6.4% over the forecast period owing to escalating demand from economies such as India and China. Sustainable demand for soil stability equipment in residential and non-commercial infrastructure projects in Argentina, Brazil, Chile, and Colombia is expected to translate into a collective incremental opportunity of US$ 210.6 between 2016 and 2024. The North America regional market is expected to represent an incremental opportunity of US$ 453.3 Mn over the forecast period.

(This article comes from Designing Buildings editor released)

Development and application of straight seam gas pipeline in deep sea

With the gradual depletion of land energy, sea energy development has become a key area, so the importance of the construction of submarine pipeline is increasingly prominent. Since the 20th century, the United States in the 1950s, the first submarine pipeline in Mexico since the laying of the first submarine pipeline laying the depth of the world’s largest submarine pipeline 3052m, and China there is no deep-sea pipeline with the production of pipe precedent.

China has more than 3 million km2 of marine land area, and actively develop and use marine oil and gas resources, is part of the national energy strategy. In recent years, with the domestic offshore oil and gas exploration equipment and technology capacity enhancement, as well as large domestic steel pipe and pipe plant pipe linepipe production equipment and development capabilities continue to improve, submarine pipeline construction has made great progress .

South China Sea Liwan submarine pipeline project is China’s first deep-sea gas project. Deep-water section of the pipeline will be laid in the 1500 meters deep sea, steel pipe to withstand the external pressure of 15MPa, the internal pressure of 29.4MPa, but also to withstand wind, waves, water, ice and seismic environmental load caused by pipeline translation and vibration, Therefore, the requirements of steel pipe with the ability to resist large deformation, requiring high strength steel pipe, wall thickness, diameter, with a large aspect ratio and excellent fracture toughness.

  • To ensure that the steel has excellent fracture toughness. Because the pipeline in the deep sea service, in the event of fracture, will be a major disaster. In order to make steel pipe has excellent fracture toughness, must meet the CTOD, DWTT and CVN and other performance indicators, so the raw material composition of the alloy composition demanding, high purity steel, while the steel residual elements As, Sb , Sn, Bi, Pb and B have strict requirements, raw materials, control and smelting difficult.
  • Thickness specifications, low-temperature fracture toughness difficult to achieve technical requirements. DWTT performance requirements of steel at the test temperature of -10 ℃, the average percentage of the shear area of ​​85%, for the steel plate is required to test temperature -20 ℃, the percentage of the shear area to achieve this requirement, which for thick steel plate It is difficult to achieve, because the compression ratio is small, difficult to control the central segregation, and the other is the thickness of the various parts of the grain size uneven.
  • The yield strength fluctuation range of steel pipe is narrow, and the horizontal and vertical are the same requirements, in the steel pipe production control difficult.
  • Steel pipe diameter to diameter ratio, forming difficulties, deformation strengthening, pipe performance before and after the difference is also large.

1500 meters deep pipeline with a large number of smooth production and successful use, creating a straight seam submerged arc welded pipe for the first of its kind in the deep sea, which is to enter the deep sea mileage card, with great economic and social benefits.