Distributed with this memorandum is the publication entitled drilled shafts. It is imperative that all stakeholders in the process have a good understanding of the basic requirements and characteristics of drilled shaft concrete. Drilling the hole in one continuous process is faster than drilling a shaft excavation. The manuals authors are three of the countrys top experts in drilled shaft design and construction.
May 15, 2018 this type of casing is often used when a drilled shaft must be installed through the water and the protruding portion of the permanent casing is used as a form. Permanent casing thickness design and plan reporting. Performing organization name and address arizona state university 10. Download geotechnical engineering software shaft 2017 developed by ensoft. It is important to keep slurries and drilling fluids out of the rock socket. However, geotechnical design models for axial and lateral. The use and construction of drilled shaft foundations. Example 10 sign structure foundation design example statement. Dimaggio of the strategic highway research program shrp2 at the. This chapter describes the placement of concrete for drilled shafts, and the design and testing of concrete mixes with emphasis on the unique requirements of drilled shaft concrete. In the most common design condition, a drilled shaft is designed to carry load by side friction in a rock socket. Drilled shafts design and construction slide 3 of 51 concrete mix design considerations massdot lrfd design manual 2009 section 3.
Drilling software download free trial downloads try before you buy. Im specifically looking for something that includes the structural design of them, not just the py analysis of it, we currently use lpile by ensoft for that. This allows a designer to see the effects from say cutting off part of the reinforcing steel at the lower sections of a drilled shaft. This allows for the passage of a drilling tool of the proper diameter during final excavation of the borehole. The contract plans contain the actual shaft design and any and all requirements not covered in the. The mix design, means and method of concrete placement are. Placement and design of concrete in drilled shaft construction. As a general rule, if temporary casing size is not specified, most contractors will use a casing with an o. Design and construction of drilled piers reported by aci committee 336 aci 336. Bridge and pier design philosophy is such that the structure is detailed to force the ductile fusehinge to develop in the pile whereas for buildings, the hinge occurs in the beam. But the geotechnical engineer of record is saying that the more prudent option would be to advance the permanent casing down to the bottom of the drilled shaft and then extract it back to elev.
Future updates to the spreadsheet may include a displacement based analysis that allows a combination of both. Cfa foundation auger cast piles use of casing or slurry to temporarily support the hole is avoided. Design a concrete mixture proportioned according to the american concrete institute. The designer shall consider the intended method of construction temporary or permanent casing, slurry drilling, etc.
Software by bridge software institute fbdeep is a static axial capacity program used for drilled shafts and driven piles. Accordingly, this report addresses the applicability of drilled shaft foundations in the railroad industry along with general cost factors, and describes modern. There are also some public seats available occasionally at dot hosted. The casing can help advance the hole, and supports the sides of the hole. Where a drilled shaft for a pier is widened at the bottom of the boring. In spite of the fact that the dss performance depends to.
When permanent casing is or maybe required, this will be the elevation that the casing may not extend below. Placement of temporary drilled shaft placement via vibratory hammer for traffic signal base. Shaft design and detailing recommendations pile detailing. Example 10 demonstrates a design procedure for a drilled shaft foundation for a cantilever sign structure. It includes different analysis methods for sand, clay, silt, and limestone. The drilled shaft methodology is based upon federal highway administration reports. The demo version is actually the full program but will not allow users to save or run new data models. This type of casing is often used when a drilled shaft must be installed through the water and the protruding portion of the permanent casing is used as a form. Maintenance of traffic mot odot selective coordination spreadsheet. With the first commercial release release dating back to 1986, lpile has continuously been developed and improved to meet user needs and incorporate stateoftheart literature and procedures. The required depth of the concrete pier is calculated by the sum of the movement active zone depth and the pier anchor zone depth see figure 21.
Because of torque requirement the diameter and length of cfa piles are generally less than drilled. Drilling and workover software, drilling software free downloads, completions, preventative maintenance. The user may define up to 10 pile sections with nonlinear bending properties. Do not define the top of the drilled shaft in the normal manner a set distance below finished grade. Permanent casing is also used in situations where concrete must be placed in a deep, largediameter, highcapacity drilled shaft in sound rock. The use and construction of drilled shaft foundations prepared by. In effect, each drilled shaft is a unique construction project, complicaleli by the fact that the drilling and concreting occur mostly out of sight of the drilledshaft contractor and the inspector. Jun 29, 2016 it is imperative that all stakeholders in the process have a good understanding of the basic requirements and characteristics of drilled shaft concrete.
Jul 07, 2010 some nhi courses, including the drilled shaft course, can be hosted by nongovernment groups. Temporary casing to the full length of the shaft excavation may be used when the risk of excavation collapse is significant. Design capacity of drilled shafts the capacity of drilled shafts is developed from a combination of side shear and end bearing. Recommendations for installation of instrumentation, in the form of inclinometer casing and monitoring wells, are also provided. Drilled shaft concrete mix design contractor must submit a concrete design mix along with materials, including water reducer, to central materials lab at least 40 days prior to construction, for approval. An investigation of load and resistance factor design of. Criteria for the design of axially loaded drilled shafts. The materials are used by the lab to verify the contractors proposed mix design.
Shaft study of drilled shafts under axial loading software. Lpile provides several design recommendations for rebar arrangements in drilled shafts. Casing can be temporary or permanent steel pipe which provides a 100% stable excavation for the full length of the drilled shaft. Fb deep is a static axial capacity program used for drilled shafts and driven piles. Construction procedures and lrfd design methods, 2010. Drilled shaft foundation design spreadsheet currently selected. Drilled shaft bridge foundation design parameters and procedures for bearing in sgc soils 6. If temporary casing has been used to seal a dry shaft excavation, there is often an accumulation of fluid on the outside of the casing. Drilled shaft with both permanent and temporary casing.
Drilling and workover software, drilling software free downloads, completions,preventative maintenance. Chapter 9 placement and design of concrete for drilled. Side resistance will not be calculated for material above. One of the most important reasons to use casing to keep the hole open is so the bottom can be inspected and thoroughly cleaned. There are several good reasons to use permanent casing for drilled shafts. Drilled shafts are either considered to be wet or dry. The cantilever supports a sign panel attached to the horizontal support. Service limit state design of drilled shaft foundations includes the evaluation of settlement due. Drilled shaft with both permanent and temporary casing drilled shaft with both permanent and temporary casing. Design requirements drilled shaft design is performed by obs using the soils design sections s4 package.
Strength limit states for drilled shafts lateral geotechnical resistance of soil and rock stratum, for single shafts and shaft groups geotechnical axial resistance compression and uplift, for single shafts and shaft groups structural resistance of shafts, including checks for axial, lateral, and flexural resistances. As part of a fhwa test program for evaluating drilled shafts for bridge foundations. Fpasc160 design procedure for drilled concrete piers in expansive soil 17 nov 2017 issued for fpa website publishing foundation performance association structural committee page 1 of 61. Drilled shaft temporary casing installation youtube. All of the information, data and computer software. Construction procedures and lrfd design methods fhwanhi10016. Sep 16, 2016 placing temporary drilled shaft casing on sr52majestic. Sep 16, 2016 placement of temporary drilled shaft placement via vibratory hammer for traffic signal base. Design and construction of drilled piers, american concrete institute 336. As the design depends on the construction method, it becomes part of the design process. The design methods for drilled shafts presented in this chapter are largely based on empirical. Burst, collapse, tension, compression, bending, buckling and temperature effects are all incorporated into cdex to analyze the casing strings capabilities. Any drilled shaft for a major river or lake bridge or any drilled shaft longer than 80 ft.
The minimum clearance between reinforcing bars shall be 17. Lpile analysis of piles and drilled shafts under lateral. Kam ng jessica garder sri sritharan jeramy ashlock. There are also some public seats available occasionally at dot hosted courses.
Drilled pier bored pile software soilstructure software. Optionally, the user may enter nonlinear momentcurvature relationships to be used in place of the internallygenerated values. Drilled shaft foundations should be designed at the service limit state to meet the tolerable movements for the structure. Drilled shaft foundations are also referred to caissons, drilled piers, or bored piles, and consist of circular shafts of varying diameter, drilled to a design depth, reinforced with a steel rebar cage, and filled with concrete. Following is a description of a procedure for designing the depth of a drilled concrete pier when the input data from section 1. Shaft 123 is a macrodriven excel spreadsheet which utilizes vba programming for calculating ungrouted and grouted drilled shaft capacities. The example is only for the design of the shaft foundation. The intent of this paper, therefore, is to provide a brief survey of modern drilled shaft technology along with practical guidelines for drilled shaft design and construction inspection. Shaft is a computer program used to evaluate the axial capacity and the shortterm, loadsettlement curves of drilled shafts or bored piles in various types of soils. Given the necessity of a solid foundation for a drilled shaft, concrete. N that develops between the shaft concrete and the surrounding soil or the.
Based on these industry codes, standards, and specifications, reinforcement required for structural reasons in a drilled shaft, whether placed against a casing or with exposed soil, should be positioned using side form spacers. Smallerdiameter piers have been used in noncollapsing soils. Does anybody have any good recommendations for relatively cheap design software for drilled shafts. Drilled shaft design software foundation engineering. Drilled shafts caissons or drilled piers are typically high axial and lateral load deep foundation systems. Cdex, pegasus vertexs casing design software, implements an industryaccepted physics model to perform accurate and practical casing designs for complicated drilling circumstances. Placing temporary drilled shaft casing on sr52majestic. Drilled shaft bridge foundation design parameters and.
A cylindrical shaft is excavated, reinforcing steel is placed in the excavation and concrete is placed to form the shaft. This manual is the reference text used for the national highway institute nhi course numbered 2014 on drilled shafts. Drilled piers are considered to have a rock socket if either the pier is embedded the greater of 3. This manual embraces both construction and design of drilled shafts, and. When constructing drilled shafts, casing and liners are vital to the overall. Drilled shaft design software geotechvols geotechnical op 9 jan 10. Drilled shaft foundations shaft end bearing shaft skin friction constructability downdrag on shaft quality of rock socket. The drilled hole for the shaft is kept open with slurry, temporary casing or permanent casing. Cased drilled shafts are required when ground conditions are so unstable that drilled holes cannot safely be stabilized with drilling slurry or where loss of ground must be controlled. Design and construction of drilled piers section 4. A drilled shaft is a deep foundation that is constructed by placing fluid concrete in a drilled hole, typically. Lpile is a specialpurpose and internationally recognized computer program based on rational procedures for analyzing a pile under lateral loading using the py method.
For large and deep drilled shaft excavations, full length temporary casing is most effectively installed using hydraulic oscillator or rotator equipment, in advance of the excavation figure 2. Subsurface exploration is a necessity for the analysis and design of a drilled shaft landslide stabilization solution. Lpile solves the differential equation for a beamcolumn using a finite difference approach. Some nhi courses, including the drilled shaft course, can be hosted by nongovernment groups. Construction practices and defects in drilled shafts. Drilled piers socketed in hard rock are designed based on side resistance only or tip resistance only. In general, the majority of axial capacity methods used by shaft are based on the latest fhwa manual. Drilled shafts installed in lakes or rivers require use of a casing placed from above the water surface to a minimum embedment into the river or lake bottom. The concrete was guided at the top of the excavation and allowed to fall freely without striking the sides of the excavation. After the concrete had set for approximately two weeks, the drilled shaft was cored, and cores examined visually. Load transfer and capacity of drilled shafts with fulldepth casing rolf katzenbach, professor of civil engineering, institute and laboratory of geotechnics.
Drilled shafts design and construction slide 34 of 51 1. Specific task training program drilled shaft foundation construction. Drilled shafts construction procedures and lrfd design. When a drilled shaft is constructed with a permanent casing, the skin friction along the. Currently, kdot allows the use of slurries or drilling compounds above the rock socket only. When designing a drilled shaft using temporary casing, contractors. The side shear is related to the shear strength of the soil and in sands can be thought of as the lesser of the friction f r.
Drilled shafts 4 mullins design capacity of drilled shafts the capacity of drilled shafts is developed from a combination of side shear and end bearing. The rock socket should have a diameter 6 inches less than the shaft diameter and may be. The design of the concrete called for a strength of 5,000 psi at 28 days. I have never seen this done but wanted to see if this is also typical. Reinforcement in drilled shaft deep foundations pieresearch. Up until now, you needed one program for axial capacity, another for lateral load analysis and yet a third program for reinforcement design. Practices for design of bored piles drilled shafts. Drilled shaft design has progressed to the point where shafts can be founded in rocks, shales, clays, sands and gravel, and. Shaft design and detailing recommendations pile detailing may 14, 2004 this design memorandum summarizes the latest wsdotadsc recommendations on design, detailing, construction of drilled shafts in wet or dry conditions, and castinplace concrete pile detailing.
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