To aid construction, the first sets of piles may be cast with a lower grade of concrete. sprayed concrete or cladding. Diameter and spacing of the piles Testing a secant pile wall A secant pile wall (Figure 1) consists of two series of piles: primary and secondary. Age (days) Rig Weight (T) Power (KW) Torque (KNm) Max. Typically used in the construction of new build basements, Secant Piling; Contiguous Piling; Sheet Piling; Silent and Vibrationless Sheet Piling; King Post Walls; Load Bearing Piles; Close Proximity Piling; Vibro Displacement Piling; Basements; Sheet Pile Sales; Steelwork. the depth of final excavation. The piles may be constructed so that they virtually touch each other (contiguous). Secant Pile Wall Installation Method: are constructed followed by a sequence of primary piles constructed Testing a secant pile wall A secant pile wall (Figure 1) consists of two series of piles: primary and secondary. Contiguous pile walls are also suitable for a variety of soils, where groundwater lies below the maximum excavation depth. Examples of the u,~e of these wail types in Singapore soil conditions are shown in Figures 1 to 5. The diameter of each pile in a contiguous piled wall is usually not less than 300mm diameter. Pile diameters range between 450mm and 900mm and are generally The wall consists of individual piles typically installed at centres 150mm greater than their diameter. Such pile wall is mainly applied in coherent (fine-grained) materials where there is no possibility of material collapse between the piles. secant pile wall (Hard / soft) This wall is used where considerations of retained height and water retention are less critical. The commonly used retaining walls include soldier piles and lagging, sheet piles (commonly Z and U sections), diaphragm walls (commonly 0.6 to 1.0 m thick), contiguous bored piles (commonly 0.8 to 1.0 m) and secant piles. male piles through the previously cast female piles with the required design intersect utilising the casing to cut the required secant 4. These include soil type, ground water profile, retained heights, available construction time, propping arrangement, cost and design life. A secant pile wall when completed is a cost effective alternative VDW stands for ‘vor der wand’, or ‘in front of the wall’. Pipe pile walls are very similar to a soldier pile wall, and may even be considered as such. Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a deep basement or a cut and cover tunnel. The piles may be constructed so that they virtually touch each other (contiguous). A method of drainage will generally be required between the piles and any inner wall. The wall consists of bored piles typically installed at centres 150mm greater than their diameter. Continuous Flight Auger (CFA) piles offer an economic, quick, low noise and vibration solution to constructing retaining walls or bearing piles for medium to highly loaded structures. A Secant Piled Wall is a retaining wall constructed for ground retention prior to excavation. Contiguous bored pile walls consist of a line of individual piles positioned at close centres and are formed by conventional continuous flight auger or rotary auger bored pile techniques. The piles may be constructed so that they virtually touch each other (contiguous). to diaphragm wall construction. A reinforced concrete guide wall is constructed at piling platform level to aid positional and verticality tolerances for the auger / casing. Construction, Use, Advantages and Disadvantages. Secant pile walls are formed by constructing intersecting reinforced concrete piles. The piles are reinforced with either steel rebar or with steel beams and are constructed by drilling under mud. Contiguous Bored Piles/Secant Piles Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a deep basement or a cut and cover tunnel. If it is necessary, the shotcrete layer can be installed on the pile wall to stabilize the material. According to the pile layout the pile wall is divided into a secant/tangent or contiguous pile wall.. Cantilever pile wall Contiguous pile walls are cons tructed with small gaps betw een adjacent piles. unreinforced weak concrete mix constructed to a depth just below Contiguous pile walls retained by anchors or strutting systems are often supported by a waler beam to distribute the loads (and prevent anchors/struts from punching through the infill) and as a mitigation measure for the unlikely event of an anchor/strut not carrying the load. Contiguous pile walls are constructed with small gaps between adjacent piles. Contiguous piled walls consist of a row of successive unconnected cast-in-situ concrete piles constructed with small gaps between the adjacent piles, formed using CFA or rotary bored piles (replacement piles techniques). Thus, in most cases, an inner wall, which may or may not be structural, will be built or some decorative surface applied, e.g. However, while they avoid excessive excavation and assist in the control of ground movement, the risk of groundwater ingress between the piles can be significant. The drainage is usually made of perfored plastic tubes. Contiguous Pile Wall Contiguous piles are suitable where the groundwater table is below excavation level. Bored cast in-situ piles are often used as an efficient and cost effective means of constructing temporary or permanent retaining walls. Secant piling is when there is no gap between piles as a wall is made of interlocking bored piles. 19 The secant piles wall consists of two types of piles: 20 Piling - Contiguous, Interlocking and Secant Bored cast in-situ piles are often used as an efficient and cost effective means of constructing temporary or permanent retaining walls. They’re normally the fastest and most efficient piled wall option. The gaps between the piles can be grouted to form a watertight retaining wall. They’re normally the fastest and most efficient piled wall option. restraint and where working space is limited. This type of construction is in many ways similar to the contiguous In situ pile retaining walls are very popular due to their availability and practicability. 5. There is, however, a relatively large increase in cost for this system in comparison with concrete soldier piles. These may not be load-bearing and act as ‘seals’ between the main load bearing piles. Contiguous Pile Walls Used in locations where water retention is not a consideration and soils are cohesive, contiguous bored Female piles use self hardening slurry as a water and fines retaining membrane. Piling. The piles may be constructed so that they virtually touch each other (contiguous). As the piles interlock, this form of construction leads to a more efficient form of structure. A sequence of secondary piles The wall consists of bored piles typically installed at centres 150mm greater than their diameter. The techniques Alternatively (secant piles) every other pile may be constructed, with their centres less than two diameters apart. Secant pile walls are constructed when resistance to groundwater is required using the CFA technique or the cased CFA technology. When properly constructed, secant pile wall offer soil support plus full water tightness. The design can incorporate steel bar or beams for reinforcement and anchors can provide additional lateral support, if needed. male piles through the previously cast female piles with the required design intersect utilising the casing to cut the required secant 4. If the piles are constructed so that they are touching they are called contiguous piles, and they can then be grouted to form a watertight wall. Contiguous pile wall. Contiguous Pile Wall. Contiguous piled walls can be designed to accommodate vertical loads in addition to horizontal forces when they are used in permanent works and the construction techniques for both methods are the same as for foundation bearing piles. Contiguous pile walls; King post wall; Secant pile walls; Anchors - single bond length; SBMA ; Soil nails; Slurry cut-off walls; … Pile Diameter (m) Max.Pile The procedure for constructing secant piles is similar to interlocking In contiguous pile walls, the axial distance of piles is bigger than their diameter. https://aarsleff.co.uk/company-news/top-10-advantages-of-contiguous-pile-walls The wall is formed by constructing alternating primary (female) and secondary (male) piles where the secondary piles partially cut into either side of the primary piles in order to form a continuous impervious structure. The sprayed concrete process is ideally suited for the construction of single sided basement walls that have been formed using either Secant or contiguous piles. A contiguous bored pile wall is formed by constructing a series of individual vertical RC piles. The use of low-cost augers and, more particularly, Contiguous Flight Auger (CFA) rigs to drill successive unconnected piles provide an economical wall. The guide ensures that piles are accurately located to achieve an interlock (or ‘secant’) cut into the adjacent pile. Contiguous Bored Piles/Secant Piles Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a deep basement or a cut and cover tunnel. Contiguous piles are particularly suited to sites with restricted access. The equipment used to construct The Cased Secant Piling (CSP) system has been developed to combine the more cost-effective CFA technique with heavy duty casings that are more traditionally associated with rotary bored piling methods. The secant piles are reinforced with either steel rebar or with steel beams and are constructed by either drilling under mud or augering. This is common when constructing basements, underpasses or cut and cover tunnels. Primary piles are installed first with secondary piles constructed in between primary piles once the latter gain sufficient strength. Piles can be … Secant pile walls rely on the interlocking or overlapping arrangement of piles to achieve a higher level of soil retention than contiguous or soldier pile systems. Sheet piled walls are a wall made of sheet piles usually using a U or Z profile and interlocking clutches that minimise water flow through them. 19 The secant piles wall consists of two types of piles: 20 Piling - Contiguous, Interlocking and Secant Bored cast in-situ piles are often used as an efficient and cost effective means of constructing temporary or permanent retaining walls. • Contiguous pile wall • Secant pile wall – hard/soft or hard/firm • Secant pile wall – hard/hard The choice of system depends on a number of factors. Of all the methods of piling it is typically the most cost effective and least time consuming. A series of adjacent piles constructed to form an earth retaining structure as a cantilever or a propped cantilever wall. According to the type of resistance, the pile wall is divided into a cantilever or a supported structure. Typically this technique is suitable to retain stiff and cohesive The process can offer a number of facing options depending on the requirement of the lining wall. For a contiguous pile wall i.e. Secant pile construction constructing in the urban area. There are three distinct bored pile wall options in current use: Contiguous wall, Secant wall and tangent wall. Pile overlap is typically in the order of 8 cm. reinforced in the usual manner. Secant & contiguous piles. Typically, primary (female) piles are cast in situ, leaving space in between them. This space must be correctly drained, so that rainwater does not stay behind the concrete. walls. First, the primary piles are cast with a weaker, unreinforced concrete that can be cut in the second stage, when the secondary piles are bored. Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a deep basement or a cut and cover tunnel. The most common use of sprayed concrete in the civil engineering industry is the facing of piled walls. Prefabricated piles are driven into the ground using a pile driver.Driven piles are constructed of wood, reinforced concrete, or steel. Contiguous Piled Walls are used where the groundwater table is below the desired excavation level and can be installed using rotary bored or CFA techniques. A secant pile wall consists of overlapping (secant) piles to form structural or cutoff walls and achieve the required water tightness. fashion to the primary pile. Primary piles are installed first with secondary piles constructed in between primary piles once the latter gain sufficient strength. Secant and Tangent Pile Walls - Review Options in DeepEX Software. Cast the male piles with full reinforcement cage (and withdraw the casing, if used) to allow the concrete in the male piles to flow and bond with the existing concrete of the previously cast female piles. Soldier Pile Walls With soldier pile walls, the piles are fitted wider apart (up to 5 - 8 pile diameters), with the soil between piles subsequently retained. Secant piles are usually adopted where there are particular concerns about ground water. The secant piles are reinforced with either steel rebar or with steel beams and are constructed by augering. The space between them is usually filled with shotcrete and reinforcing mesh. First, the primary piles are cast with a weaker, unreinforced concrete that can be cut in the second stage, when the secondary piles are bored. When waterproofing contiguous or secant piling, the Vandex Super waterproofing layer is typically sandwiched between a layer of shotcrete and a poured concrete internal wall (see Figure 2) This method of waterproofing is dependent on the strength of the underlying piles and the tolerances between them than the Oldroyd method (see Figure 1 ). The system eliminates the need to use support fluid or casings in cohesive soils, non-cohesive or water bearing soils. The gaps between the piles can be grouted to form a watertight retaining wall. Contiguous Bored Piles/Secant Piles Description Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a dee basement or a cut and cover tunnel. Secant pile walls retained by anchors or strutting system are often supported by a waler beam to distribute the loads (prevent punching of anchor/strut through the pile) and as a mitigation measure for the unlikely event of an anchor/strut not carrying the load. A secant pile wall is a cost effective alternative to diaphragm wall construction. S = Pile Spacing (c/c) D = Pile Diameter Typically there are three types of bored pile in current use. The secant piles are reinforced with either steel rebar or with steel beams and are constructed by either drilling under mud or augering. substructures in close proximity to existing structures requiring rotary cutting heads. A contiguous pile wall is simply a row of concrete soldier piles installed so that each pile is in contact, or near contact, with piles on either side of it. A secant pile wall consists of overlapping (secant) piles to form structural or cutoff walls and achieve the required water tightness. no overlapping piles I use the following formula to work out the inertia of the wall per metre run. Closely spaced bored piles can be used to form a retaining wall, perhaps for the construction of a deep basement or a cut and cover tunnel. Secant Piled Retaining Walls Primary piles are installed first with secondary (male) piles constructed in between primary (female) piles once the latter gain sufficient strength. Cast the male piles with full reinforcement cage (and withdraw the casing, if used) to allow the concrete in the male piles to flow and bond with the existing concrete of the previously cast female piles. This form of construction ensures The gaps between the piles can be grouted to form a watertight retaining wall. The system eliminates the need to use support fluid or casings in cohesive soils, non-cohesive or water bearing soils. Contiguous piles are an efficient and cost-effective means of creating retaining structures. Continuous Flight Auger (CFA) piles offer an economic, quick, low noise and vibration solution to constructing retaining walls or bearing piles for medium to highly loaded structures. CFA piles; Driven precast piles; Bored piles; Minipiles; Restricted access piles; Pali Radice; Driven cast in-situ piles; Helical piles; Earth retention. From soil mixing to drilled shafts, Keller draws on its complete suite of techniques to optimize the design and construction of these walls. installed at pile centres of between 500 and 1000mm respectively to the full design depth, cutting into the secondary piles and Both types of walls are a type of retaining wall used when you want to go below ground. secant piles generally comprises a heavy duty CFA auger with It is normally the most economic and rapid option. bored pile method, except the gap between the primary piles is Because of the form of construction, the exposed piles will be fairly rough in appearance. filled with a secondary ‘soft pile’ consisting an The wall consists of discrete piles typically installed at centres 150mm greater than their diameter, leaving gaps … Piling - Contiguous, Interlocking and Secant . BASF Elastospray and Walltite high density spray foams can be used in place of shotcrete on secant and contiguous piles. thereby leaving gaps between the piles between 15 and 100mm. By providing specialist underpinning we can repair subsiding or sinking buildings. subsoils and where ground water levels are below the eventual The gaps between the piles can be grouted to form a watertight retaining wall. Filling of pile … Concrete Bookshop - Members receive 40% discount on Concrete Society publications. Contiguous piles are particularly suited to sites with restricted access. They are applied in liquid state, forming a high strength foam on contact that rapidly cures to give a reliable and robust surface. 5. Steel Mat Hire; Fabricated Steel; Propping Systems; Jetties and Working Platforms; Pedestrian Bridges; Temporary Bridges Pile walls can be either closely-spaced contiguous piles walls or secant pile walls. The options include: 1. CFA piles; Driven precast piles; Bored piles; Minipiles; Restricted access piles; Pali Radice; Driven cast in-situ piles; Helical piles; Earth retention. Bored cast in-situ piles are often used as an efficient and Of all the methods of piling it is typically the most cost effective and least time consuming. Secant Wall Piling – hard/soft or hard/firm. of concrete similar to the primary pile and reinforced in a similar Because the piles are discreet the retaining function of the wall relies upon the soil between the piles arching. Our specialist piling contractors offer comprehensive building foundation packages, installing piles for both commercial and domestic clients across the midlands and southern England. The gaps between the piles can be grouted to form a watertight retaining wall. Secant Pile Walls –Soft mix BNZ Auckland •Strength of “soft” mix –Fit for purpose •Infill between piles •Unreinforced •Strength & Batching variance of small quantities 0 2 4 6 8 10 12 0 7 14 21 28 35 42 49 56 63. avoids excessive excavation and assists in the control of ground From soil mixing to drilled shafts, Keller draws on its complete suite of techniques to optimize the design and construction of these walls. piles, save that the secondary pile is not soft but constructed The piles may be constructed so that they virtually touch each other (contiguous). Piling. Pile overlap is typically in the order of 3 inches (8 cm). It depends on what you are modelling; if the provided loads are given for 3m worth of bridge or what have you, then multiply Iyy by 3, or alternatively divide the loads by 3. For excavations in soft soils, rigid walls such as diaphragm walls and contiguous bored pile walls are commonly used as they are more effective than the more flexible walls such as sheet pile walls, in limiting soil movements to an acceptable level. Underpinning. that water entry into the subsequent excavation is greatly reduced. In-fill piles are then bored, cutting into the adjacent piles to form a continuous structure. When waterproofing contiguous or secant piling, the Vandex Super waterproofing layer is typically sandwiched between a layer of shotcrete and a poured concrete internal wall (see Figure 2) This method of waterproofing is dependent on the strength of the underlying piles and the tolerances between them than the Oldroyd method (see Figure 1 ). Contiguous piles are suitable where the groundwater table is below excavation level. movement. Secant piles are reinforced with either steel rebar or steel beams. Alternatively (secant piles) every other pile may be constructed, with their centres less than two diameters apart. Primary piles are installed first with secondary (male) piles constructed in between primary (female) piles once the latter gain sufficient strength. The piles may be constructed so that they virtually touch each ot (contiguous). In the final basement wall condition, the contiguous piles would normally be shotcreted to prevent any loss of retained soil between the piles over the life of the structure. It is a vibration-free and low noise drilling procedure used for installation of single piles, as well as contiguous, tangential or secant pile walls. The wall consists of individual piles typically installed at centres 150mm greater than their diameter. The use of low-cost augers and, more particularly, Contiguous Flight Auger (CFA) rigs to drill successive unconnected piles provide an economical wall. The use The use of low-cost augers and, more particularly, Contiguous Flight Auger (CFA) rigs to drill Secant Pile Walls are formed by constructing intersecting reinforced concrete piles. Alternatively (secant piles) every other pile may be constructed, with their centres less than two diameters apart. During excavation of the soil, the piles will generally require propping before the permanent floor and/or roof structure are completed. Secant pile walls are formed by constructing intersecting circular reinforced concrete piles. A contiguous bored pile wall is formed by installing closely spaced bored piles, with a gap between adjacent piles of typically 75 to 150mm. A Secant pile wall is formed by installing overlapping bored piles. current use: Contiguous wall, Secant wall and tangent wall. Contiguous pile wall is executed with a spacing between piles. Secant or tangent piles are columns constructed adjacent (tangent) or overlapping (secant) to form structural or cutoff walls. Depending on geotechnical characteristics of the location and project requirements, we differentiate several types of pile wall. Secant Pile Walls –Soft mix BNZ Auckland •Strength of “soft” mix –Fit for purpose •Infill between piles •Unreinforced •Strength & Batching variance of small quantities 0 2 … Contiguous pile walls are constructed with small gaps between adjacent piles. Primary (female) piles are constructed first using a ‘firm’ concrete / bentonite (commonly 10N/mm2). Performance advantages: Wooden piles are made from the trunks of tall trees. The CSP method can be used to construct deep secant or contiguous piled walls depending on the actual ground conditions and water table. cost effective means of constructing temporary or permanent retaining When properly constructed, secant pile wall offer soil support plus full water tightness. They may be constructed either by using segmental temporary casing and conventional heavy duty rotary drilling tools or by continuous flight auger (CFA) techniques. The gaps between the piles can be grouted to form a watertight retaining wall. Pile overlap is typically in the order… Contiguous bored pile wall (gap between piles) – no water seal / permanent works Secant piled walls – this includes hard/firm and hard/hard secant pile walls, – watertight / temporary works In order to ensure the high verticality tolerances and maximum water tightness; we recommend that secant walls be constructed through concrete guide walls cast ahead of piling works. The sprayed concrete process is ideally suited for the construction of single sided basement walls that have been formed using either Secant or contiguous piles. Contiguous Piled Walls are used where the groundwater table is below the desired excavation level and can be installed using rotary bored or CFA techniques. Contiguous pile walls retained by anchors or strutting systems are often supported by a waler beam to distribute the loads (and prevent anchors/struts from punching through the infill) and as a mitigation measure for the unlikely event of an anchor/strut not carrying the load. Piling Contractors. The design can incorporate steel bar or beams for reinforcement and anchors can provide additional lateral support, if needed. It is normally the most economic and rapid option. Secant or tangent pile walls can be constructed in a wide variety of soil conditions, including through cobbles and boulders. Secant or tangent piles are columns constructed adjacent (tangent) or overlapping (secant) to form structural or cutoff walls. depth of excavation. Secant pile walls are formed by constructing reinforced concrete piles that interlock, and are often used as a cost-effective solution when short-term water retention is required. 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