Schlüsselelemente für erfolgreiches Spundbohle-Fahren

Den Ingenieuren stehen viele Design- und Analysetechniken zur Verfügung, wenn es darum geht, die effektivsten Installationsmethoden für Bleche und Pfähle zu bestimmen. Die vier Grundelemente, die für ein erfolgreiches Ergebnis zu berücksichtigen sind, hängen in einfacher Weise ab von:

  • Topographische Merkmale
  • Geologische Bedingungen
  • Verwendung der geeignetsten Art von Blechprofil plus
  • Die richtige Wahl des Fahrhammers

Im Wesentlichen wird die Wahl des treibenden Hammers durch die ersten drei Punkte in unserer obigen Liste bestimmt. Zum Beispiel werden topografische Merkmale wie Wohnhäuser, nahegelegene Straßen oder unterirdische Dienste oft Lärm- und Vibrationsbeschränkungen erzeugen. Hochfrequenz-Vibratoren und Resonanz-Freie-Vibratoren werden oft dort eingesetzt, wo potentiell gefährliche Schwingungen minimiert und lokalisiert werden müssen. Als zusätzliche Vorsichtsmaßnahme können Rammarbeiten effektiv mit einem Vibrationsmonitor gemessen werden, der mit akustischen und visuellen Alarmen unterstützt wird, um das Risiko unerwünschter Schadensansprüche zu minimieren.

Unter Berücksichtigung topographischer Grenzen werden geologische Aspekte wie die vorherrschende Bodenart und -beschaffenheit die beste Art von Rammgerät für den Einsatz bestimmen. Eine Standortuntersuchung, die visuelle oder Bohrlochproben einschließen kann, sollte durchgeführt werden, um festzustellen, ob ein Schlaghammer oder ein Vibrationshammer verwendet werden sollte. Im Allgemeinen sind schwierige Fahrbedingungen wie schwere Tone, verdichteter trockener Boden und Gesteinsschichten Beispiele dafür, wann ein Schlaghammer die effektivsten Ergebnisse liefern würde. In Fällen, in denen der Boden unterschiedliche Unterschichten aufweist, kann die Verwendung eines Pre Auger verwendet werden, um die Wahrscheinlichkeit eines erfolgreichen Rammens zu erhöhen, wenn ein Vibrationsantrieb verwendet wird.

Vibrationshämmer sind besser geeignet für die körnigen und kohäsiven Bedingungen in Sand, Kies und anderen partikulären Böden. Der Pfahl wird unter Verwendung eines Gegengewichtsystems angetrieben, das eine Hochgeschwindigkeitsvibration erzeugt, die es dem Pfahl ermöglicht, in den Boden zu gelangen, wenn der Boden durch die Vibrationen fluid gemacht oder “verflüssigt” wird. Im Gegensatz zu Impact Hammers wird der Pfahl normalerweise unter seinem eigenen Gewicht plus dem des Vibrationshammers angetrieben. Abhängig vom Rüttlermodell kann bei Bedarf zusätzliches Gewicht aufgebracht werden, um den Fahrprozess weiter zu verbessern.

Die Verwendung eines herkömmlichen Schlagbohrers kann mit dem Hämmern eines Nagels in ein Stück Holz verglichen werden, während das Verwenden eines Vibrationshammers als das Blatt beschrieben wurde, das wie ein heißes Messer durch Butter durch den Boden verläuft. Ein Vibrationshammer, der unter den richtigen Bodenbedingungen eingesetzt wird, kann die Fahrzeit erheblich verkürzen und die Kosten für die Vorarbeit verringern.

Die Auswahl des am besten geeigneten Spundbohle-Typs und -Abschnitts hängt von einer Reihe von Grundlagen ab, einschließlich: Bodentyp, erforderliche Eindringtiefe und beliebige Spezifikationen für den Ausschluss von Wasser oder Feinstaub. Das Hauptziel ist es, sicherzustellen, dass der Pfahl auf die erforderliche Tiefe gefahren werden kann, wobei alle Einschränkungen und Beschränkungen eingehalten werden. Die fortschreitende technologische Entwicklung der Schlag- und Vibrationsantriebsausrüstung hat dazu geführt, dass breitere und dickere Profilpfähle effektiver installiert werden können. Bei der Verwendung von Schlaghämmern bleiben jedoch Faktoren wie die Blechdicke ein wichtiger Aspekt, da eine Beschädigung des Blechkopfes möglich ist, wenn das Stahlprofil zu dünn im Verhältnis zur Bodendichte ist.

Ingenieure sind instinktiv bestrebt, Arbeitsszenarien zu schaffen, bei denen die geringste Anzahl von Pfählen für ein bestimmtes Design verwendet wird, und es wird unvermeidlich einen Kompromiss geben, der darauf abzielt, ein Gleichgewicht zwischen Kosteneffizienz und erfolgreichem Pfahlrammen zu finden.

Dieser Artikel stammt von vpgroundforce bearbeitung freigegeben

Key Elements of Successful Sheet Pile Driving

There are many design and analytic techniques at the disposal of engineers when it comes to determining the most effective installation methods of sheets and piles. In simple terms, the four basic elements to consider in order to achieve a successful outcome are dependent on:

  • Topographical features
  • Geological conditions
  • Use of the most appropriate type of sheet section, plus
  • The correct choice of driving hammer

Essentially, the choice of driving hammer will be determined by the first three points in our above list. For example, topographical features such as residential dwellings, nearby roads or buried services will often generate restrictions on noise and vibration. High Frequency Vibrators and Resonance Free Vibrators are often used where there is a need to minimise and localise potentially hazardous vibrations. As an added precaution, pile driving activities can be effectively measured by use of a Vibration Monitor supported with Audible and Visual Alarms to minimise the risk of unwanted damage claims.

Having considered topographical limitations, geological aspects such as the prevailing soil type and condition will determine the best type of pile driver for the job. A site investigation, which may include visual or bore hole samples, should be undertaken to ascertain whether an impact hammer or a vibratory hammer should be used. Broadly speaking, difficult driving conditions such as heavy clays, compacted dry soil and rock strata are examples of when an impact hammer would produce the most effective results. In cases where the ground has varying sub-layers, the use of a Pre Auger can be used to increase the likelihood of successful pile driving when using a vibratory driver.

Vibratory Hammers are more suited to the granular and cohesive conditions found in sand, gravel and other particulate soils. The pile is driven using a counter-balance system which generates a high speed vibration, allowing the pile to travel into the ground as the soil is made fluid or ‘liquefied’ by the vibrations. Unlike Impact Hammers, the pile is usually driven under its own weight plus that of the vibration hammer. Depending on the model of vibrator, additional weight can be applied if necessary to further improve the driving process.

Using a traditional impact driver can be compared to hammering a nail into a piece of wood, whereas using a Vibratory Hammer has been described as the sheet passing through the ground like a hot knife through butter. A vibratory hammer ‘used in the right soil conditions’ can significantly decrease driving time and mitigate groundwork costs.

Selecting the most appropriate sheet pile type and section will depend on a number of fundamentals, including: soil type, required depth of penetration and any specification for water or fine particle exclusion. The principal objective is to ensure that the pile can be driven to the required depth while adhering to any limitations and constraints. Progressive technological development of impact and vibratory driving equipment has meant that wider and thicker section piles can be more effectively installed. However, factors such as sheet thickness still remain a major consideration when using impact hammers as damage to the sheet head is possible if the steel section is too thin in relation to the soil density.

Engineers instinctively strive to create working scenarios where the least number of piles are used for a given design and there will inevitably be a trade-off which aims to strike a balance between cost effectiveness and successful pile driving.

This article comes from vpgroundforce edit released

Все о шпунтового ограждения стен: типы, материалы и методы строительства

шпунтового ограждения стены широко используются как для больших, так и для небольших набережных сооружений, начиная от небольших прогулочных шлюпок и заканчивая большими доковыми сооружениями, где океанские суда могут перевозить или разгружать грузы. Причал, выступающий в гавань, состоящий из двух рядов набивки листов, чтобы создать пространство между тем, которое заполнено землей и вымощено, является общей конструкцией.

Свайные шпунты также используются для защиты от эрозии берегов; для стабилизации грунтовых склонов, особенно для дорог; для крепления стен траншей и других раскопок; и для коффердамов. Когда высота стены около 3 м высотой, она часто консольна; однако для больших высот стен он обычно закрепляется с использованием одного или нескольких якорей. Результирующая стенка называется закрепленной стеной или скрепленной переборкой.

Методы строительства

При строительстве стеновых стенок шпунтового ограждения можно вбить в землю, а затем засыпку, помещенную на землю, или шпунтового ограждения сначала можно вбить в землю и почву перед шпунтового ограждения выемки. В любом случае почва, используемая для засыпки за стеной, обычно является зернистой. Почва ниже линии экскаватора может быть песчаной или глинистой. Поверхность почвы со стороны воды обозначается как линия бурового раствора или линия экскаватора.

Преимущества:

Стальные шпунтовые сваи являются наиболее распространенными из-за нескольких преимуществ перед другими материалами:

1. Обеспечивает высокую устойчивость к ударным нагрузкам.

2. Легкий вес

3. Можно повторно использовать несколько проектов.

4. Длительный срок службы выше или ниже воды со скромной защитой.

5. Легко адаптировать длину свай сваркой или болтами

6. Суставы менее склонны к деформации во время движения.

Эта статья опубликована в выпуске civilengineeringbible edit

Everything about sheet-pile walls: types, materials and construction methods

Sheet-pile walls are widely used for both large and small waterfront structures, ranging from small pleasure-boat launching facilities to large dock structures where ocean-going ships can take on or unload cargo. A pier jutting into the harbor, consisting of two rows of sheet piling to create a space between that is filled with earth and paved, is a common construction.

Sheet piling is also used for beach erosion protection; for stabilizing ground slopes, particularly for roads; for shoring walls of trenches and other excavations; and for cofferdams. When the wall is under about 3 m in height it is often cantilevered; however, for larger wall heights it is usually anchored using one or more anchors. The resulting wall is termed an anchored sheet-pile wall or anchored bulkhead.

Sheet pile wall types:

1. Wooden sheet piles

2. Steel sheet piles

3. Concrete

4. Light-gauge aluminium sheet piles

5. Vinyl sheet piles

6. Fiberglass sheet piles

Construction Methods

In the construction of sheet-pile walls, the sheet pile may be driven into the ground and then the backfill placed on the land side, or the sheet pile may first be driven into the ground and the soil in front of the sheet pile dredged. In either case, the soil used for backfill behind the sheet-pile wall is usually granular. The soil below the dredge line may be sandy or clayey. The surface of soil on the water side is referred to as the mud line or dredge line.

Advantages:

Steel sheet piling is the most common because of several advantages over other materials:

1. Provides high resistance to driving stresses.

2. Light weight

3. Can be reused on several projects.

4. Long service life above or below water with modest protection.

5. Easy to adapt the pile length by either welding or bolting

6. Joints are less apt to deform during driving.

This article comes from civilengineeringbible edit released

Braced sheet pile shoring wall in sensitive clay

This case history describes the design and performance of a temporary braced sheet pile shoring wall constructed within the median between heavily-trafficked lanes of the Trans Canada Highway in Langley near Vancouver, British Columbia, Canada. The excavation extended to 9.7 m depth below the existing road grade into soft, high plasticity, sensitive glaciomarine clay. Glaciomarine clay is locally notorious for excavation and embankment stability and foundation settlement problems. The shored excavation was required to provide an access pit to allow the installation of a 3 m diameter steel pipe culvert by Horizontal Pile Driving (HPD).

The braced sheet pile wall was designed using the Terzaghi Apparent Earth Pressure distribution and conventional limit equilibrium analysis methods. The excavation was undertaken in stages as the bracing was installed and ground deformation was monitored using slope inclinometers and by survey of surface targets. The case history describes the performance of the excavation and compares predicted to monitored displacements. A particular issue related to face stability due to clay squeezing and running sand during bulkhead sheet pile removal required to commence HPD for culvert installation. The bulkhead face was stabilized by grouting with a water reactive polyurethane grout prior to sheet pile removal.

This article comes from scholarsmine edit released

Mitigación del asentamiento de la estructura existente por tablestaca tablestacado paredes cuando licuefacción

La licuefacción durante los terremotos induce el daño de las estructuras existentes como levantamiento o asentamiento, dependiendo del peso de la estructura. Es importante mitigar el daño que ocurre por licuefacción para tomar algunas contramedidas contra el desplazamiento vertical dañino.

Este estudio se enfoca específicamente en contramedidas contra el asentamiento inducido por la licuefacción de las estructuras existentes con las paredes de Tablestaca tablestacado durante los terremotos. Para este propósito, el estudio considera los efectos de los muros de tablestacas sobre la disminución de asentamientos inducidos por licuefacción de estructuras existentes usando las pruebas modelo bajo condiciones normales de gravedad (1 g) que simulan la situación de estructuras existentes fundadas en depósitos de arena.

Los resultados muestran lo siguiente: cuanto más largas son las paredes de tablestacas que se instalan, más se puede reducir el asentamiento de las estructuras. La adaptación combinada de la instalación de paredes de tablestacas con una disminución en el nivel del agua subterránea genera un gran grado de reducción en el asentamiento de las estructuras que con la adaptación de la técnica única de instalación de la pared de tablestacas o desagüe de GWL.

(Este artículo proviene de waseda edit released)

Waling in general

The waling diverts forces from the sheet pile to the anchorage and stiffens as well as aligns the construction. In general, tension walings are positioned on the inside of the main wall, whereas they are usually attached as compression wales behind the wall in case of anchor walls.

EAU 2004 recommends the solid construction as well as generous dimensioning the waling and preferring heavy waling made from S 235 JR (formerly St 37-2) over the lighter types from S 355 J2G3 (for- merly St 52-3).

Load-bearing welding seams must be 2mm thicker than statically necessary due to risk of rusting.

It is recommended to dimension the wales according to the allowed anchor force of the chosen anchor. Apart from horizontal load due to anchor tension, rope tension and forces caused by traffic, the waling is also subject to vertical stress caused by anchor vertical load, soil load and its own weight. There may also be horizontal axial loads along the sheet pile axis due to, for example, rope tension.

Hot Rolled Steel Sheet Pile Sections

Hot rolled steel sheet pile sections have a connection “interlock” at both ends of the section. These interlocks connect with one another to form a continuous wall of Sheet Piling. Soil conditions may allow for the sections to be vibrated into the ground instead of being hammer driven.

Typically hot rolled steel sheet piles are 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. The wall of sheeting provides excellent resistance to bending forces and is used to provide structural strength to a foundation.

U Sections
U shaped sheet pile sections are well proven in both permanent and temporary works throughout the world. Our L and STU series U sections are available in 750/700/600/500mm system widths. All U sections incorporate well-known and efficient Larssen interlocks and offers excellent sealing application.

Z Sections
Z Sections: Continuous form of the web and location of the interlock symmetrically on each side of the neutral axis provides positive influence on the section modulus on the Z section.

Special Sections
Flat sheets, Larssen L430 sheet pile sections and box piles are all types of special sections. Find out their special capabilities and how you can use them in construction.

Corner Sections
Our Corner Sections To find out more and to receive a free consultation e-mail us or call us at 1300 764 164 .

Steel Grades for Steel Sheet Piles
Conditions of supply Hot rolled steel piles are supplied according to DIN EN 10248, cold roll formed piles according to DIN EN 10249.

This article comes from ThyssenKrupp Steelcom editor released

Elaborate on Steel Sheet Piling

Steel sheet piles are long structural sections with a vertical interlocking system that creates a continuous wall. The walls are most often used to retain either soil or water. The ability of a sheet pile section to perform is dependent upon its geometry and the soils it is driven into. The pile transfers pressure from the high side of the wall to the soil in front of the wall.

There are permanent and temporary applications. Permanent sheet piles remain in the ground and serve as permanent retaining structures. Temporary sheet piles are designed to provide safe access for construction, and are then removed.

Hot rolled and cold formed are two primary methods of manufacturing sheet pile. While there are key differences between these two methods, the most important distinction is the interlock. Since hot rolled sheet piles are produced from steel at high temperatures, the interlock tends to be tighter than its cold formed counterpart. Normally, looser interlocks are not recommended in extremely hard driving conditions or for walls requiring low permeability. Hot rolled sheet piles are generally larger and have a broader range of strengths than cold form sheet piles, but there is a large overlap between the two, especially in the most common sizes.

This article from the Skyline Steel editor released