INSTALLATION OF RETAINING WALL – SHEET PILE WALL

The following pictorial guide illustrates the installation sequence of a typical sheet pile wall. This type of retaining wall was used for the construction of HarbourFront Station on the North East Line (NEL).

  1. Position of Sheet Pile
    A guide frame/guide beam is placed on the ground to set out the position of the sheet pile wall.
  2. Installation of First Sheet Pile
    The piling rig lifts up the first sheet pile and drives it into the ground, leaving about 1 metre length of the sheet pile above the ground level.
  3. Installation of Second Sheet Pile
    The piling rig drives the second sheet pile into the ground and the second sheet pile interlocks with the first sheet pile.
  4. Repetition of Process
    Process 2 and 3 repeats till the installation of sheet piles is completed within the length of the guide frame/ guide beam.
  5. Extension of Sheet Pile
    If the first set of sheet piles installed are not long enough to reach the required depth in the ground, extension of sheet piles is required. This is done by welding the ends of a second sheet pile length to the one driven in earlier and driving the combined length into the ground.

(This article comes from www.lta.gov.sg editor released)

City Hall: Easport fire station gets technology upgrade

The Eastport Volunteer Fire Department in cooperation with the Annapolis Fire Department recently purchased a cardiac monitor/defibrillator, called LifePak-15, at the cost of about $30,000.

In addition to its full 12-lead EKG transmission, oxygen saturation monitoring, and non-invasive blood pressure monitoring capabilities, the LifePak-15 has dozens of new features and technical enhancements that will improve the entire spectrum of emergency care, from the incident scene all the way to the hospital emergency room.

“This unit provides our Annapolis paramedics with the most up-to-date cardiac rescue technology,” Annapolis Fire Chief David Stokes said.

The LifePak-15 was paid for with grant money from the state and donations from the Eastport Volunteer Fire Department.

Eastport Volunteer Fire Company President Al Kirchner thanked Eastport’s citizens, civic groups and businesses for their continued support.

“This accomplishment belongs to the generous people in our community who helped pay for it,” he said.

Over the past five years, the Eastport Volunteer Fire Company has spent more than $790,000 for apparatus, equipment and improvements at the Eastport fire station.

The Eastport Volunteer Fire Company has served Eastport and the greater Annapolis community since 1886. The group meets monthly on the fourth Wednesday at 7:30 p.m. at the Fire Hall at 914 Bay Ridge Avenue in Eastport. The company welcomes anyone wishing to become a member or simply help out with the company’s programs related to fire and emergency medical services.

Bulkhead replacement

Many of you have contacted the city regarding the City Dock Bulkhead Replacement Project. The project is on schedule and within budget.

The contractor receives six shipments of steel sheet piles each week at 6 a.m. These shipments are escorted by the police to the location so there is no interruption in traffic during the morning rush hour. To date, there has been 475 linear feet of steel sheet pile driven of 700 total linear feet.

Once the piles are driven to the proposed tip elevation, they are cut off to grade. Along Dock Street, 294 linear feet of existing concrete seawall has been demolished and removed, 270 linear feet of new seawall has been fully formed (including rebar, conduit, pedestal bond cuts and step forming) and is ready for concrete. Two hundred linear feet of stone backfill has been placed, 200 linear feet of electrical conduit has been installed and nine mooring bitts (of 48 total) have been installed in the formed seawall.

Pile driving activities on this project are due to be completed by mid-February and the overall Bulkhead Project will be done by April 8.

Currently, there are five seismic monitors installed around the perimeter of the project within a 100-foot radius of the project. The locations were identified by Seismic Surveys Inc. (SSI) and approved by the design team structural engineers.

SSI is the same firm that provided monitoring on the City Dock Phase 1 project completed in April 2008. The seismic monitors record the vibrations 24 hours/day, 7 days/week. A Pre-construction Survey of all structures within a 200-foot radius was completed prior to the start of the pile driving.

Interim surveys are conducted on a monthly basis. The first monthly survey was conducted Dec. 8-10. The results indicate “no construction related changes were observed” at any of the structures. The second monthly survey is currently underway. In an effort to be proactive, the contractor is in the process of opening a claim with their insurance company so that an adjuster will be available to evaluate any damage claims.

Nuisance flooding, primarily due to rain events, continues to be an issue and the city uses two Vactor trucks (1,000 gallons each) to remove the water from the Dock Street parking lot in front of the Harbor Master building.

Weekly updates on the project can be found at www.annapolis.gov.

(This article comes from Capital Gazette editor released)

Fiber-reinforced polymer lock gates installed in the Netherlands

The Wilhelminakanaal in Tilburg, Netherlands has installed the largest fiber-reinforced polymer lock gates in the world (6.2 x 12.9 m). The gates were manufactured using the InfraCore Inside technology, and can withstand a height difference in water levels of no less than 7.9m.

The glass fibers to reinforce the structure are constructed using InfraCore Inside technology, which makes it possible to build fiber-reinforced polymer sandwich constructions whereby the upper and lower shell are inextricably linked, meaning they are capable of bearing very heavy loads. The gates have a yellow protective coating and will require minimal maintenance.

One important sustainability factor is that because fiber-reinforced polymer does not decay, these lock gates have a predicted life two or three times that of conventional wooden or steel gates. And because the gates have roughly the same specific gravity as water, there will also be much less wear and tear on the pivoting points.

The choice to install fiber-reinforced polymer lock gates was a joint initiative of the province of Noord-Brabant, Rijkswaterstaat, and the building group combination Heijmans/Boskalis. The lock gates were manufactured by the Dutch company FiberCore Europe (Rotterdam, Netherlands) and the installation was carried out by the construction company Hillebrand. Smaller lock gates (5 x 6.2 m) had already been installed in lock III in October last year.

The Wilhelminakanaal has been both widened and made deeper near Tilburg. In addition, the existing locks II and III have been replaced by a single new lock, and new sheet piling installed together with the laying out of more environmentally friendly banks. There will also be a swinging basin where vessels can turn. To achieve all this, Rijkswaterstaat has worked in collaboration with the municipality of Tilburg, the province of Noord-Brabant and Combinatie Heijmans/Boskalis to realise improved navigability of the Wilhelminakanaal. A wider and deeper canal will make Brabant more sustainable and improve its accessibility by water. Once the project has been completed, larger ships (class IV vessels) will be able to sail this section of Wilhelminakanaal in Tilburg more quickly.

(This article comes from compositesworld.com editor released)

Types of Sheet Pile Walls

Sheet piles are pre-cast members comprising varieties ranging from simple wood planks and light gauge sheet metals to heavy sections made of reinforced concrete and structural steel members.

Timber sheet piles – These are generally used for temporary structures and braced sheeting in excavation works. If it is to be used in permanent structures above water table, some form of preservative treatment shall be given. Even given the preservative treatment the life of timber sheet pile is short, Timber sheet piles are joined by means of tongue and groove joint. Timber piles are not suitable in the strata consisting of gravel and boulders.

20160118 a

Concrete sheet piles – These are pre-cast concrete members usually joined by tongue and groove joints as shown in Fig.2 below. They are relatively heavy and bulky and displace large volume of soil during driving. This large volume displacement increases the driving resistance. Handling and driving should not damage the piles and suitable reinforcement shall have to be provided for this purpose.

20160118 b

Steel sheet piles – Steel sheet piles are the most common types. These piles have several advantages over the other types of piles. Some of the important advantages are:

  • It is resistant to high driving stresses developed while driving in hard and rocky material
  • It is lighter
  • It may be used several times
  • It can be used either below or above the water table
  • It has longer life
  • It has got high salvage value
  • Joints suitable for a particular job can be provided so that it does not deform during driving
  • The pile length can be increased either by bolting or welding

Steel sheet piles are available in market in several forms. In Fig.3 below, some common types are shown. The deep are webs and Z piles are used where large bending moments are to be resisted as in the case of anchored and cantilever walls. The shallow arc piles can be used where the bending moments to be resisted are less. Straight web sheet piles are used where the web will be subjected to tension as in the case of the cellular cofferdams. The ball socket types of joint offer less resistance to driving as compared to thumb and finger joint.

20160118 c

(This article comes from Best Engineering Projects editor released)

Trail connector work underway off Warden Bridge

The Sun River trail connector project is underway along the 10th Avenue South bridge.

The contractor, Sletten Construction Co., is using a barge to minimize impact to motorists, Andrew Finch said.

The project will connect 10th Avenue South at the Warden Bridge to 6th Street Southwest on the southside of the Sun River and the north side of Country Club Boulevard.

The city conducted a special bike/pedestrian count in that area over the summer to be able to measure the trail’s impact once it’s completed.

Finch said they did a week’s worth of counts in June 2015 and found that on an average weekday, there were 17 pedestrians and 28 bicyclists using the shoulder of the road on 10th across from the country club entrance. On weekends, the average daily counts were 29 pedestrians and 33 bicyclists.

“Although we knew there were folks using the roadway, these numbers were higher than expected, given the unsafe conditions that currently exist,” Finch said.

The contractor is working on pulling away the large rocks on the riverbank and installing sheet piles that crews can backfill so there will be a level surface for the trail, which will be paved.

The trail will be cantilevered a few feet over the sheet pile with a rail, Finch said.

“The design really minimized the impact on the riverbank,” he said.

Finch said the project is expected to be completed around August since crews can’t do some of the work until it warms up.

(This article comes from Great Falls Tribune editor released)

PZC and PZ Steel Sheet Pile

PZ and PZC sheet piles are also called Larssen sheet piles, mostly used in USA. Some middle American countries also prefer these sections.

Larssen sheet piling has been widely used in the transformation of waters and along the coastal areas of infrastructure. The development of China’s economic will occur wiht the series of mega projects, at the same time, China’s high-speed railway, intercity rail lines, construction of State Road highway traffic, all needs foundations and cofferdams. In the natural state of crushed gravel (particle size less than 20mm), sand, silt, etc., foundation bearing capacity in 100KN / m2 following geological conditions, hot rolled steel sheet piling can be driven up to 30 times

Hot rolled steel sheet piling use a thin sheet (common thickness 8mm ~ 14mm), to roll forming machine processing. Its low cost of production and the price is cheap, length control is also more flexible. But the simple processing methods and the same thickness all sheet piles, also result in increased cross-sectional dimensions and cannot optimize the amount of steel.

According to the actual situation of the project, client can select the most economical and reasonable cross-section, optimize engineering design, material savings of 10-15% compared with the performance, greatly reducing the construction cost.

Installation of Steel Sheet Piling

Procedure and Equipment

According to Recommendations of the Committee for Waterfront Structures Harbours and Waterways EAU 1996, “Steel sheet piling is frequently an ideal solution both as regards structural considerations and driving conditions, which is also capable of absorbing localized overloading without endangering overall stability.” (Section 8.1.3.1, page 280).

The installation of a combined sheet piling wall system is typically a two- or three-step process:

  1. Use a vibro hammer to drive the beams or king piles as far as possible.
  2. Use an impact hammer to drive the beams to the designed toe depth (if necessary).
  3. Set the intermediate sheet piling (with attached connector) between the king piles.

Recommendations of the Committee for Waterfront Structures Harbours and Waterways EAU 1996 also notes that, “The embedment depth of the intermediate piles for high harbour walls in good bearing soil should be at least 2.5 m; for low walls with slight water pressure difference, it should be at least 1.5 m.” (Section 8.2.10.4, page 355).

Strengthening the Wall for Hard Driving Conditions

A toe adjustment can be made at the mill (for an additional fee) or by the contractor on site:

20160113

A note on driving, and the advantages of driving a combined sheet piling wall:

The fact that you only need to drive the beams to full depth and then simply set the intermediate sheets is an extremely important advantage of the combined sheet piling wall over heavier sheet piling from contiguous walls.

Driving Experiences and Practical Tips

A traditional combined sheet piling system has a typical sheet width of 6.33 feet (1.93 M) – two halves of each beam, two connectors, and two intermediate sheets. The usual sheet-to-beam ratio in a combined sheet piling wall system is around 75% sheet to 25% beam. Hence, you are likely to only encounter hard driving 25% of the length of a combined sheet piling wall system versus 100% hard driving for a contiguous sheet pile wall. In some cases where hard driving was experienced, it has been documented that up to 22 combined sheet piling wall sections have been driven in one 10-hour shift, amounting to well over 100 wall feet; in the same conditions, however, the same exact crew was only able to install about 1/3 of the wall feet with the heavy contiguous sheet piling that needed to be driven to full depth.

Another advantage of driving hot rolled combined sheet piling over traditional contiguous walls (such as with cold formed sheets) is addressed in the U.S. Army Corps of Engineers’ 1994 Sheet Piling Design Manuals for Engineers. Cold-rolled sections have a weaker interlock than the hot-rolled sections and in hard driving conditions this interlock might “unzip” or cause alignment problems which would require replacement of the sheet piles. The cold-rolled sections also are usually thin and may be prone to overstressing during driving” (Section 8-8a).

(This article comes from iSheetPile editor released)

Driven Piles: Advantages and Disadvantages

Piles may be of timber, steel or concrete. When the piles are of concrete, they are to be precast.

They may be driven either vertically or at an angle to the vertical. Piles are driven using a pile hammer. When a pile is driven into granular soil, the soil so displaced, equal to the volume of the driven pile, compacts the soil around the sides since the displaced soil particles enter the soil spaces of the adjacent mass which leads to densification of the mass. The pile that compacts the soil adjacent to it is sometimes called acompaction pile. The compaction of the soil mass around a pile increases its bearing capacity.

If a pile is driven into saturated silty or cohesive soil, the soil around the pile cannot be densified because of its poor drainage qualities. The displaced soil particles cannot enter the void space unless the water in the pores is pushed out. The stresses developed in the soil mass adjacent to the pile due to the driving of the pile have to be borne by the pore water only. This results in the development of pore water pressure and a consequent decrease in the bearing capacity of the soil.

The soil adjacent to the piles is remolded and loses to a certain extent its structural strength. The immediate effect of driving a pile in a soil with poor drainage qualities is, therefore, to decrease its bearing strength. However, with the passage of time, the remolded soil regains part of its lost strength due to the reorientation of the disturbed particles (which is termed thixotrophy) and due to consolidation of the mass. The advantages and disadvantages of driven piles are:

Advantages

1. Piles can be precast to the required specifications.
2. Piles of any size, length and shape can be made in advance and used at the site. As a result, the progress of the work will be rapid.
3. A pile driven into granular soil compacts the adjacent soil mass and as a result the bearing capacity of the pile is increased.
4. The work is neat and clean. The supervision of work at the site can be reduced to a minimum. The storage space required is very much less.
5. Driven piles may conveniently be used in places where it is advisable not to drill holes for fear of meeting ground water under pressure.
6. Drivens pile are the most favored for works over water such as piles in wharf structures or jetties.

Disadvantages

1. Precast or prestressed concrete piles must be properly reinforced to withstand handling stresses during transportation and driving.
2. Advance planning is required for handling and driving.
3. Requires heavy equipment for handling and driving.
4. Since the exact length required at the site cannot be determined in advance, the method involves cutting off extra lengths or adding more lengths. This increases the cost of the project.
5. Driven piles are not suitable in soils of poor drainage qualities. If the driving of piles is not properly phased and arranged, there is every possibility of heaving of the soil or the lifting of the driven piles during the driving of a new pile.
6. Where the foundations of adjacent structures are likely to be affected due to the vibrations generated by the driving of piles, driven piles should not be used.

(This article comes from Builder’s Engineer editor released)

Steel Tie Rod

Tie rod systems are also know as deadman anchors, the most economical sheet piling tie back and anchor. Steel tie rods are manufactured from two forms:round steel tension bars and tie bars with upset forged ends. The thread is either cut or rolled onto the tieback anchors. We can produce the most comprehensive tie rod system in the world. Marine tie rods diameter from 20mm to over 300mm. Tension bar steel grade from S235 S460 up to S1030(minimum yield strength 1030Mpa). Tie bar quantity from 2500 tons in Paksitan Qasim port project, to only 3 pieces in UK poole combiwall system, there is no order too big or too small for us. We can supply tie rods with our sheet piling, pipe pile in a package, we are also pleased to supply tie rod only (By calcuation of anchor force, distance between two adjacent tie rods, angles, soil conditions etc, our engineers team will design the most proper marine tie rod to suit your project).

Our factory is the exclusive combination of designing, manufacturing, testing of sheet pile tie rods in China. With 4 professional product lines namely forging product line, heat treatment line, machine-work line and surface treatment line, our annual production capacity exceeding 35 thousands tons There are also many advanced equipments in the product line such as 15m ultra-long electric heating mantles, 15m large-sized ball blast machines, automatic numerical control machines, and 2500t, 2000t, 1000t, 500t forging machines designed and manufactured by ourselves.

Specialised in production design sales of sheet piling, pipe pile and accessories, Nanjing Grand Steel Piling Co.,Ltd (Short for Grand Piling) is the biggest and most experienced sheet piling solutions suppliers in China. Grand Piling produced and exported the first sheet piles in China. During the past years, Grand Piling cooperated closely with numerous big construction companies, piling contractors, piling stockists / traders, design institutions, and gain vast experiences in this filed. Grand Piling know clients’ every needs and problem,  and our engineer team will design the most economical while competent offer for every inquiry. Grand Piling is your first call, when you are involved in civil foundation works, port and harbors, bridge, Rivers, etc.

The imperviousness of steel sheet pile walls

For practical design purposes it is advisable to assess the degress of the required seepage resistance in order that a cost effective solution may be selected. Depending on the requirements, there are basically three possible solutions:

  1. In applications such as temporary retaining walls a moderate rate of seepage is often tolerable. An SSP wall made of piles with the famous Larssen interlock provides sufficient seepage resistance.
  2. In applications where a medium to high seepage resistance is required – such as cut-off walls for contaminated sites, retaining structures for bridge abutments and tunnels – double piles with a workshop welded intermediate joint should be used. The workshop weld is as impervious as the steel itself. The free interlock of the double pile needs to be threaded on site with a filler material. The lower end of the resistance range is adequately served by the various bituminous fillers, but it is noted that their use is limited to water pressures less than 100 kPa.For high resistance requirements, as well as water pressures up to 200 kPa, a waterswelling product should be used as a filler material. A wall designed in this way is between 100 to 1000 times more impervious than the simple sheet pile wall with Larssen interlocks.
  3. A 100% watertightness may be obtained by welding every joint.
    Double piles with a workshop weld are used for the construction of the wall. The interlock that needs to be threaded on the job has to be welded on site after excavation.

If a comparison needs to be made between the rate of seepage of an SSP walls and a slurry wall, the table below may be used. For a given SSP walls, the hydraulic conductivity which a slurry wall of thickness D has to provide in order to obtain the same upper limit on the discharge – at the same water pressure – as the SSP wall, can be determined.

(This article comes from J Steel Australasia editor released)