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By Tim Chapman

This general report considers what promoters of deep basement projects want from their teams and whether they get it often enough. Most large projects are based on complex financial models where the funding is related to a future income stream. Project delays and cost over-runs can critically affect the financial model. Too often, delays and cost over-runs originate in the substructure and foundations. We must take positive steps to improve our industry's reputation for reliability.

Jan 1, 2006

By A. Paviani

The subject of this session is "Equipment Installa­tion, Recent Developments". This is a subject which is not usually addressed at conferences of Foundation Engineering. It is rare to find sessions dealing with the technological side of deep foundations, a subject which only recently seems to have aroused sufficient interest at national and international conferences. It is therefore natural for the subject of "Equipment", or the tools used to implement the various "technologies", to be over­looked or mentioned only occasionally during the discussion of other issues. At conferences, most of the attention is attached to research and to the theoretical interpretation of the performance and behaviour of deep foundations, as well as to establishing the most suitable calculation algorithms and approaches for the study, design and control of foundation structures. It is almost as if the subject of equipment is felt to be less important or, perhaps, that it is considered to belong more strictly to mechanical engineering than to civil engineering.

Jan 1, 1994

By David Miller

"The biggest concern about using soil mixing is the inability to observe physically the final product, which has led to a lack of confidence about what is in the ground. After all, you can’t see it and you can’t taste it and you can’t smell it, so are you sure it’s soil mixing? In addition, there are variations in techniques, tools and monitoring that have led to additional skepticism and the desire to “elevate” the product. This skepticism is why the industry is so scrutinized even when there are other technologies being used that do not experience nearly the same level of scrutiny. With other techniques, even with a slurry wall, you can see the backfill before it goes into the ground, and drilled piers have careful evaluation of the concrete mix even before placement into and verification of the open hole. Essentially, you get control over the final material. There is less control in soil mixing, and it’s very dependent on in-situ conditions. These factors make it difficult to rely solely upon installation parameters, quality control (QC) and verification tests. At some point, you may need to apply some engineering judgment.Start at the BeginningThe availability of sufficient and accurate geotechnical data (soil type, heterogeneity, shear strength parameters, variability, etc.) is important in establishing the material that will be drilled. This data will also help in determining the proper mix design to achieve the desired soil cement properties. Many factors must be considered when designing the mix and the mixing program, including any debris in the ground, different soil properties and varying moisture contents.Each of the various factors affect the final properties of the soil cement, so it really takes careful planning and evaluation of the mix design through iterations by looking at the soil types and adjusting the mixes. Clay is going to behave very differently than sand in both mixing efficiency and final properties. That is, the presence of clays results in more difficulty in achieving higher strengths and to physically mix the soil and the binder, whereas the presence of sands results in more difficulty controlling the final permeability."

Jan 1, 2017

By Maurice Guillaud

The most striking innovations on diaphragm-wall construction plant are those associated with continuous real-time trajectory monitoring of the excavating tool (either a grab or a hydro-cutter). The recent equipments are fitted with clinometers and gyrometers to control deflection, rotation or deviation from the vertical, thus allowing to install diaphragm-walls with a verticality accuracy of less than 0.3%. One of the greatest advantages of extensive use of on-board IT systems on the Hydrocutters and hydraulic grab machines is that it aids quality control by automatically producing complete real-time reports of all excavating data (verticality, depth, type of ground, rate of progress, stoppages, etc.). These reports are available to the Engineer, providing the total transparency required for Works Supervision and the Quality Assurance Plan. They also provide the Contractor with input data for databases used for optimising efficiency and progress criteria on future jobs.

Jan 1, 2002

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Jan 1, 2003

By W. G. K. Fleming

The general history of piling is traced up to the present time with regard to the evolution of methods and materials. The processes have been strongly influenced by developments in basic equipment and industrial change. It is noticeable that in the twentieth century more progress has taken place than in the many previous centuries. It has been strongly influenced by the general development of Soil Mechanics. Test loading is probably the most effective way to assess the success of designs and many empirical relationships have been challenged through it. As we approach a new century it appears that it will be an age of rapid equipment development, with much enhancement of understanding of what has been done. Processes of automatic construction and testing will becoming commonplace. These changes will narrow the limits of conventional scatter that have come to be accepted and to a large extent will be driven by political efforts to curtail energy consumption, to raise standards of quality and reliability, and to conserve the environment. 1. Ancient history. Piling is an ancient art. Its first mention in history is from Herodotus, the first person to commit an account of his times to the written word in the years 557 to 479 BC. He evidently had a strong interest in engineering matters because he wrote of building, brick making, reinforced brickwork, river training, canal building, bridge construction, tunnelling and its acoustic detection and piling. The piling reference comes from Book 5 at paragraph 16.

Jan 1, 1999

Jan 1, 1992

By G. Stuart Littlejohn

In spite of recent concerns in certain European countries, I believe that silicate-ester grouts will continue to be employed in practice, unless more cost-effective inorganic grouts are developed for the treatment of fine sands. It is also noteworthy that over the past 40 years, there has been a record of good experience where silicate-ester grouts have been used in ground improvement. Nevertheless, there is now a need via the European Standard EN 12715 (2000) "to assess the environmental impact, particularly the toxicity of the grout and grout components, and their effect on ground and drinking water should be considered before grouting." "When testing the grouting material for environmental impact, the following aspects should be considered: ? Whether during processing, transport or grouting, substance can be generated or released which could be hazardous to the environment or the grouting crew; ? Whether noxious substances can spread upon mixing with ground water; ? Whether reaction products can be produced or released which influence the water quality; ? The type of particles eroded from hardened grout; ? Chemical reactions between hardened grout and the ground water."

Feb 10, 2003

By Douglas Heenan

The fracture orientations were inferred based on theory and previous experience. The fracture pattern was not monitored during the project. Grout volume was recorded at each sleeve port and real time movement monitoring of the building foundation was performed.

Feb 10, 2003

By Peter Iovino

Unfortunately, I don't know the unit cost per cubic yard of treatment. I reflected on that yesterday and I don't think that we considered the use of micropiles. They could have been an option. The challenge may have been picking up some of the lateral load but I think the micropiles could have been installed on a batter and perhaps extended to rock. We could have considered them, but I do not believe we explored micropiles as an option for this project.

Feb 10, 2003

By Masaaki Terashi

The machine for the hybrid method called JACSMAN is ordinarily a dual shaft machine. Each shaft has augers at three different levels and nozzles for jetting at two different levels. The distance between two shafts may be changed according to the particular requirements. Figure 4 shows single shaft and a treated soil column created by the method. The diameter of the auger is 1.0 m. As the jetting nozzles locate at the periphery of the auger, jetting can achieve the additional treated soil column beyond the diameter of the auger. The diameter of the jetting improvement is fixed at 2.3 m.

Feb 10, 2003

By Dennis Wrixon

It was a little bit exceeded. The decision was the uniform settlement is measured at each one corner and the highest one corner is the important one. And in addition there is a differential settlement of 2.1 mm allowed. So we reached about 7.8 or 7.9 mm with the highest corner and in addition 2.1 so it was a little too much. But behind there is a very difficult calculation of the authorities where all of the displacements are combined together and there are of course some more factors of safety in these settlements.

Feb 10, 2003

By John L. White

The vibro driver/extractor is a machine that grips to a pile and vibrates it up and down. When the vibrating pile is lowered into the ground, all soil around the pile begins to vibrate. A vibrating pile breaks the friction between the pile and the soil, thus allowing it to penetrate the ground. A vibro is usually operated by hoisting it into the air with a crane and then placing it onto the pile. The vibro has hydraulic gripping jaws that are controlled from the ground. Once the operator has successfully lowered the vibro onto the pile, the jaws are closed and locked onto the pile and operations can begin. Please see the drawing below: [ ]

Jan 1, 1990

By BRETTMANN TRACY

Jan 1, 2000

By Trent Dreese

For critical velocities in gravel units we use Bush-Luckner, Sichardt, other empirical equations, and equations derived from laboratory experiments too. On the base of these, we compiled critical velocity - permeability coefficient dependencies. Under the lower border of these dependencies sand particles can't be moved, and thus they are stable. For critical velocities in the fissures of flysh and volcanic rocks we use Ronzhin (1974) criteria derived from laboratory experiments in Russia. Maximal filtration velocities measured by tracer methods in gravel soils and in fissured rocks have smaller values then the critical ones.

Feb 10, 2003

By Krishnendu Mandal

"For a multi-story building project in Kolkata, a pile load testing program was conducted to minimize pile performance uncertainty resulting from variable subsurface conditions and to verify the pile load vs. settlement response. The program consisted of performing five (5) instrumented load tests on augured cast-in-place (ACIP) pre-production test piles. Vibrating-wire strain gages and extensometers were installed in the test piles at strategic locations to enable measurements of the load vs. deformation behavior of the test piles. This paper presents a description of site subsurface conditions, test pile installation, instrumentation setup for a maintained load test (MLT), static compression pile load test results, and pile instrumentation result interpretation. Average mobilized unit shaft resistance values are calculated.2.0 INTRODUCTIONThe project site is located in Kolkata, near river Ganges, and the proposed development plans consist of constructing six (6)25-story (G+25) towers; see Fig. 1 and Fig. 2 below for approximate site location and proposed development layout, respectively. The buildings were designed to be supported on ACIP piles. A field load test program was implemented to verify sub-surface conditions and pile design. The test program consisted of installing Five (5) instrumented test piles numbered LP1A and B through LP6A and B, and performing static compression load tests on these piles. The piles were instrumented with vibrating-wire strain gauges and extensometers, so that the pile shaft resistance distribution along pile length and the pile toe resistance could be interpreted using direct instrumentation measurements."

Jan 1, 2015

By Stefan Mewes

Europe’s second-largest seaport has installed a new combi wall consisting of pipe piles, sheet piles and inclined shaft grouted piles to support it. The new Liebherr piling rig with swinging leader was used to drive shaft grouted piles into a very dense soil layer of sand with glauconite. The 60 m Liebherr swinging leader was suspended at an inclination of 45° via a suspension frame and suspension ropes from the crawler crane. This inclined installation of shaft grouted piles via freely hanging swinging leader, as used for this project, is unique in Belgium. Moreover, the pile length of 43 m is a novelty for this type of pile. Shaft grouted piles consist of a steel profile with a separate box-like pile shoe with an open top. A thin grout is injected via an injection pipe during driving and emerges just above the pile shoe. As the pile is driven further down, so compressing the ground, the space above the pile foot is immediately filled with grout under pressure. This piling system is ideally suited for the transfer of high tensile loadings. It is a method to increase geotechnical load-bearing capacity and to reduce negative skin friction during pile driving.

Sep 1, 2022