The Geotechnical considerations of Sheet Pile Basement Construction require a solid foundation. The piles should be built from steel sheet piling, which is a high-quality product with a superior structural integrity and superior resistance to soil stresses. The piles should be durable and withstand a tremendous load without requiring maintenance. In most cases, they last for years, and require little or no care after the installation process.
Geotechnical considerations
Sheet pile basement construction has a few specific considerations related to its geotechnical characteristics. It must be able to withstand a certain amount of water seepage, a controlled amount in some cases. For example, underground car parks are often designed to tolerate a controlled amount of water seepage. For such structures, research has quantified the water seepage and the required measures to avoid it. In addition, fire resistance must be factored into the design process.
If the depth of the basement is six meters or more, bending moment becomes an important consideration. Geotechnical considerations of sheet pile basement construction depend on soil properties and the water regime. There are two types of basement walls: cantilever walls and multi-propped walls. To design a steel sheet pile wall, uncorroded section properties and the superstructure loads must be known. The basement walls must also be designed based on the building structure analysis and the unfactored loads.
The bottom soils of a basement must be properly dewatered to avoid the walls from collapsing and losing their bearing capacity. In deep excavations, penetrating the basement walls may be more cost-effective than enclosing them. When designing a basement wall, keep in mind that corners of the basement are the most susceptible to pipe-related failure. Also, consider the depth to which a water table reaches the bottom of the excavation.
Steel sheet piles
Steel sheet piling is a common choice for basement construction. This type of foundation is strong, durable, and incredibly resistant to soil stress. This type of piling is used to support the basement floor and can last for decades while requiring only light maintenance. Below-grade construction is especially beneficial because it can be done without drilling. But before you choose steel sheet piles for basement construction, learn about the different types of foundations.
There are three basic types of piling: the drilled shaft, the fixed strand, and the pile. A steel sheet pile is installed on top of it, and a liquid membrane is placed on top of it. The foundation supports this structure by preventing water, gas, and vapour from getting inside. It also features a conformable adhesive and a protective white coating. Each of these layers work together to form a microscopic integral seal, ensuring no noise or vibrations escape. In addition, this type of foundation also allows for a faster installation rate, with fewer disruptions to adjacent structures.
Steel sheet piles are versatile construction materials. They can be used in earth-retaining walls. Some are permanent, while others are temporary. In permanent foundations, steel sheet piles can prevent backfill soil from collapsing. But in some building construction projects, such as in basements, temporary foundation supports may be required. The use of temporary foundation supports is a common way to avoid basement settling and soil settling.
Cantilever walls
Cantilever walls in sheet pile basement construction are similar to cantilevered beams in their performance. They are constructed using sheet piling drilled into the ground to a depth sufficient to be a vertical cantilever. The lateral support of cantilever walls comes from passive pressure on the embedded por tion. However, the large penetration depths of cantilevered walls may lead to high moments and are not recommended for non-ferrous sheeting.
For these structures, the active pressures of the soil must be calculated for the most likely conditions of low water. It is important to consider the effect of tidal forces, which can significantly increase the active pressures. Heavy rain or melting snow also add significant loads to the active side of the wall. The earth pressures can be estimated through graphical methods, but they should take into account other factors such as surcharge loads, seepage, and ground water.
When used for basement walls, cantilever walls offer many advantages. These walls allow for minimal construction widths and are highly effective in supporting the vertical loads of a structure above. This option is particularly efficient for car parking areas, as it can be driven tightly into the boundaries of the site. The thin walls enable car parking spaces to be built closer to existing structures, minimizing costs per bay. A common advantage of sheet pile basement construction is that it does not require a concrete facing wall, which can drastically reduce the cost per parking space.
Single-prop walls
The use of multi-prop walls is the preferred method of water resistant basement construction. While many applications of such walls include underground car parks, the fact that they can withstand a controlled amount of water seepage is not generally recognized. A recent study quantified this phenomenon and showed that basement walls constructed with multi-props have a much higher water resistance than single-prop walls. To determine whether this type of construction is suitable for your needs, follow these simple steps:
To design a single-prop wall, consider the remaining excavation space and soil conditions. The depth and water regime of the basement will determine the best type of wall support for the building. For medium-retained heights, consider the BS 8002 code of practice for earth retaining structures, which you can use in conjunction with the guidance of structural and geotechnical engineers. A deep basement, up to 6m, requires a team of engineers with experience in geotechnical design and construction. In such a case, steel intensive basement construction is the most appropriate choice.
Multi-prop walls are redundant structures. CIRIA Report 104 provides two methods for calculating structural forces on multi-prop walls. One of these is called the Working Conditions method. The other method is the Ultimate Conditions method. The CIRIA report also shows that the Working Conditions method is more reliable than the previous two. Because the soil and wall have complex interactions, the distribution of forces and earth pressures can vary significantly.
BS 8110
BS 8110: Part III – Sheet Pile Basement Construction specifies the requirements for sheet pile basement construction. These specifications specify the depth and radii of pile penetration, the type of anchor used and the design earth pressures. The method for calculating the bending moment of piles is based on a design procedure that incorporates a number of model tests. The bending moment of piles is the result of a series of passive and active earth pressures.
A pile must be more powerful than the soil beneath it. This guide uses British piles, 500 mm wide, and the panel driving method. It must be noted that wider piles may require heavier sections. The point resistance of the pile at the toe is the primary consideration. The friction of the shaft with the soil contributes little to the overall resistance. Despite the limited number of factors governing pile penetration, the BS 8110 sheet pile penetration guide provides important guidance on proper installation.
BS 8110 Sheet Pile Basement Construction is the most popular method of basement construction. In fact, many residential developments use this method. The main advantage of this method is that the foundations of adjoining buildings can be lowered without disturbing the structural integrity of the basement walls. However, this method is not suitable for basements in areas of high ground settlement, because the soil must be able to absorb the load.
Protective coatings for sheet piles
If you want to extend the functional life of your sheet piles, there are many different coating options available. In this article, we’ll examine the different types of coatings and how they can affect your project. The top choice of protective coating is an epoxy coating, which is an organic or synthetic material. It can be applied to sheet piles to increase their corrosion resistance and withstand the elements. A duplex coating combines epoxy and hot tip galvanizing to provide maximum protection and longevity.
Fire resistance is an important consideration in any basement construction. Many buildings are designed to be fire resistant and should incorporate adequate fire safety engineering. Fire safety assessments should be performed along with initial design. Listed below are some generic protection systems:
Coal tar epoxy coatings are the most common corrosion protection method for steel sheet piling. They are cost-effective and offer outstanding protection from exposure to weather elements. To ensure the durability of your sheet piles, ESC employs SSPC-certified paint inspectors. All ESC products are sand-blasted to SSPC10 standards. The standard color for coal tar epoxy coatings is black.
Other types of basement construction can benefit from this method. The Westminster City School is a voluntary, aided, non-diocesan school that has been in operation in the Victoria district of London since 1877. The school received a PS152 million investment from Westminster City Council to renovate its building. During the demolition process, the school demolished two Victorian buildings and built two new facilities and an administration unit. As a result, the school needed a waterproofing system for the sheet pile walls and concrete floors.
