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By Chris G. Leach

"Abstract A seven storey Northbridge area of Perth, Western Australia presented residential apartment complex located in the an opportunity for a novel application of Cutter Soil Mix technology (CSM). The development included a two-level basement for car parking which covered the full site area. However, the basement was also required to extend under an existing single story heritage building. Soil conditions comprised 2m of fill overlying medium dense to dense sands that in turn were overlying a very stiff clay stratum at approximately 14-16m depth. The ground water table was located at a depth of approximately 1m below the natural surface level.A site boundary consisting of a reinforced CSM retention system and was designed and installed to allow the excavation to proceed to basement level. Two rows of temporary soils anchors or inclined struts were required to achieve this. A CSM support system for the heritage building was also designed and constructed to provide temporary support during excavation and permanent construction works. The brief for the contract works emphasised that it was vital that settlements of the heritage building be kept within strict limits.CSM is a relatively new introduction to the Australian construction market, using a modified trench cutter to mix a binder slurry with in situ soils, generally to form cut-off walls, retaining walls and soil improvement works. This project is understood to be first application of the CSM for underpinning work in Australia.This paper discusses the site background details leading to the decision by the client to adopt CSM technology, and the design and construction aspects to meet the challenges offered by this project.Introduction190 Newcastle St is a 7-level residential apartment complex located in the Northbridge area of Perth, Western Australia. The development includes a 2 level basement for car parking, which covers the full site area. The basement also extends under a single story heritage building, which remained in-situ throughout the building works.A site boundary retention system was required to allow the excavation to basement level to proceed. In addition, a support system for the heritage building was required to provide temporary support during excavation and permanent construction works."

Jan 1, 2014

By R. T. Stain

Dynamic methods of load testing piles using a drop hammer to generate the input force have been in use for many years. These systems are based on the wave equations developed at the Case Institute of Technology, Cleveland, Ohio in the late 1960's and are well documented. Such tests are generally restricted to preformed driven piles, the driving hammer being a convenient means of generating large input forces. In 1979 the CEBTP (France) was sponsored by the FNTP (Fédération Nationale des Travaux Publics) to undertake research into existing classical methods and to develop a test that would be equally applicable to bored cast in place piles. The result of this research programme is a methodology known as SIMBAT, and which was included in a series of class A prediction trials in Belgium in 1987 (Refs 1 & 2, Paquet 1987, 1988). The purpose of this paper is: a) to examine the type of 'dynamic'/'static? load test correlations that can be obtained. b) to highlight the differences between the classical' methods and the 'SIMBAT' technique.

Jan 1, 1989

By Louis Donolo

New buildings in today's urban environment, especially in down-town areas, invariably involve the construction of multiple level basements. Used for parking, storage and commercial space, these underground structures normally extend 30 to 50' and more below grade and, to make optimum use of expensive land, they usually occupy the full site right up to street/sidewalk and property lines. SOIL SUPPORT SOLUTIONS Building these basements requires vertical excavation, and consequently, a temporary soil support system which will eventually be replaced by the permanent foundation walls of the structure.

Jan 1, 1987

By Michael J. Brown

It is often necessary to undertake some form of pile testing to verify design calculations. Historically this has been limited to static and dynamic tests. Newer rapid testing methods such as Statnamic are seeing more frequent use. This form of testing can be advantageous due to short set up time and test duration. Although the methodology suffers from a lack of formalised guidance and may prove difficult to analyse in certain soil conditions. This paper investigates the suitability of Statnamic testing and analysis for a range of soil and pile types as well as different installation methods through a number of case studies undertaken in the UK. Recommendations are made on test specification and analysis.

Jan 1, 2006

By Mait Mets

In Estonia, the deformations monitoring of 1500 buildings are currently under investigation, buildings on pile foundations make up 10 per cent of these. In the following text we will be considering the behaviour of pile foundation buildings in various parts of Estonia, in differing geotechnical conditions.

Jan 1, 2002

By S. Merjan

Three papers were presented for discussion at the conference: 1) Instrumented driven steel tube piles at Canary Wharf; author: A. R. Gaba, United Kingdom. The author described the Canary Wharf development in the London Docklands, and in particular, the decision to build over the water by driving open-ended steel piles 25m in length into the sands below the soft estuarine deposits. The tubes were then filled with concrete above the sand plug (usually 17m below pile head). Three trial piles were instrumented with: a) resistance strain guages on the inside of the tubes; b) vibrating wire guages on the re­inforcement of the concrete. The trial piles showed elastic behaviour in five cycles of lateral loading, while the verticle load tests showed a definite bi-linear load-settlement behaviour. The initial stiff portion was a result of frictional staff resistance, both inside and outside the tube, with the soil at the base contributing at higher settlements. Loads were taken to three times working load, with no imminent signs of failure.

Jan 1, 1991

By Hui Yongning

This paper presents a simulating test of constitutive relation of soil anchor in laboratory and puts forward a new plastoelastic mechanical model, on which a new calculating formula of elastic and plastic limit bearing capacity for soil anchor is suggested and two engineering projects verify that this method is adaptable.

Jan 1, 1991

By Virendra Singh

The load settlement behaviour of single pile or pile group may be obtained using computer based methods such as the finite or boundary element techniques. An alternative method of obtaining the vertical soil stresses adjacent to the Pile is presented Based on calculated stresses consolidation settlement for Piles foundation is obtained. This approach may be computationally more attractive than the more general finite or boundary element techniques.

Jan 1, 1996

By M. Makarchian

Existing buildings sometimes experience excessive settlement under their design loads, or due to increased foundation loading, if a change of building use is required. One of the oldest and widely numerical study has been carried out of a simple idealised problem of an underpinned rigid circular foundation to better understand the behaviour of pile used for underpinning and load transfer mechanism from an existing foundation to the underpinning piles. The finite element method has been used for this analysis, with the soil treated as a two-phase elasto-plastic material. It is found that the effect of the length of the pile becomes more significant as pile length increases. As would be expected, the earlier the pile is installed, the less is the final settlement.

Jan 1, 1996

By G. Price

The Building Research Establishment installed a base load cell in a driven cast-in-place pile prior to it being tested under vertical load. The monitored base loads were found to be significantly less than could have been predicted by current design methods. The less than expected capacity was attributed to the drilling out procedure. An electro-level system installed in a second similarly formed pile, provided detailed information on the performance of the pile under lateral load. The information obtained was used to check several current design methods for laterally loaded piles. The findings show the potential dangers of attempting to improve design parameters from only limited performance data.

Jan 1, 2010

By Bjöm Böhle

Top-down construction (or cut and cover construction) is providing important advantages when comparing with conventional construction techniques for commercial developments with deep basements, underground car parks or near surface infrastructure and traffic tunnels. Main features are substantially reduced restrictions to surface usage, avoidance of intervention with adjacent property, provision of rigid substructures resulting in minimal deforma­tions and settlements and, last but not least, accelerated construction pro­gramme. The present contribution illustrates the construction method in general and elaborates in detail on the special foundation works for a major urban commercial high rise development requiring a six level basement structure.

Jan 1, 2006

By Liqun Liang

Various nondestructive testing (NDT) inspection methods are available to evaluate the structural integrity of cast-in-place shafts. The widely used methods include Cross Hole Sonic Logging Testing and Low Strain Testing. Due to its advantages such as low cost, easy operation, quickness and flexibility (no need to plan ahead and prepare inspection tubes or other devices), Low Strain Test is frequently specified in quality assurance programs of many countries or when doubts arise as to the integrity of the finished shafts/piles. The method is well suited for small to middle sized shafts. However it is an indirect NDT testing method and has certain limitations. Data interpretation requires proper training, experience and judgment and, therefore, inconsistent conclusions and reporting may be provided by different testers. To avoid or reduce such inconsistencies, it is best to follow a standardized data interpretation and record classification system. In this paper, a new classification method is presented with examples. A step-by-step data evaluation and interpretation procedure is proposed with examples of real cases to help understand the LST data. The paper also makes recommendations for measures to be taken when anomalies are detected in tested production piles.

Jan 1, 2011

By David A. Hart, Barry P. Osborn, Richard J. Totty, Ana T. Carvalho, Max B. Elliott

This paper addresses the experience designing and installing bored piles for the King’s Cross area. This includes continuous flight auger and rotary bored piles, with a range of diameters between 600 mm and 1200 mm, reaching a maximum depth of 56 m below ground level. Existing Network Rail Thameslink twin bored running tunnels are located directly beneath the subject plots. These tunnels have an external diameter of 6.6 m and the crowns of the tunnels are very shallow, in some cases just 10 m below the existing ground level. Some plots needed piles to be installed in close proximity to the tunnels, which required additional control measures and contingency plans. Pile verticality was monitored as the tip of each pile advanced and in-tunnel monitoring readings were verified and are presented. Lessons learned from designing, installing and testing the piles and monitoring the tunnels are addressed in this paper.

May 1, 2022

By D. Mohan

Soft to medium dense silty and clayey soils are found in many parts of India and conventional friction piles have normally been used for foundations of high rise buildings and other structures on such soils. The author investigated the use of Bored Compaction Piles and these have been used on these soils achieving substantial economies in cost over conventional friction piles. Similarly highly expansive clays, commonly known as Indian Black Cotton Soils occupy about 20 percent of the Indian land area. Short bored underreamed piles have been developed for such soils and a very large construction of various types of buildings and other structures have come up on such piles over the last thirty years in various parts of the country. The paper describes investigations leading to the design and development of both these type of foundations.

Jan 1, 1989

By Enrique Ibarra, Manuel J. Mendoza

"Abstract: This paper describes the current state-of-practice for the design of cast-in-place drilled shafts in granular soils under axial loading, addressing recent advances that take into account the surrounding soil grain size distribution and their behavior. The important role of the gravel content in the shaft response under axial loading is emphasized. Usual design approaches in Mexico are described, and the results of load tests from different sources are discussed. The analysis emphasizes the primary contribution of the lateral area of shafts to their axial bearing capacity, raising doubts regarding the common local idea of “point bearing shafts”. Finally, some lines of research are noted to permit advances in the important field of deep foundations. 1 INTRODUCTIONIn Mexico, cast-in-place drilled shaft foundations are widely used to support various structures in the west area of Mexico City, where alluvial and volcanic deposits predominate. Deep foundations are also used in modern construction works located in other major cities of Mexico. In fact, the use of drilled shafts for tall buildings and overpasses in the center of Guadalajara as well as in transportation works related to the Metro and roadways in Monterrey is well known. It is worth mentioning that these same structures have been applied in road bridges throughout the country.Procedures for pile construction in Mexico have been basically the same for the past 20 years (Paniagua et al., 2005); however, modern equipment has been incorporated into the construction industry, including innovations in sludge-drilling technology, control and the quality of the castings. In addition, novel and efficient procedures such as construction with continuous auger displacement piles have been implemented (Auger Cast in Place, ACP) and have begun to be used locally with success (Schmitter and Paulin, 2006).However, it can be argued that the technological developments that have resulted in more efficient construction procedures have not included a breakthrough in the full understanding of the phenomena or basic mechanisms of load transfer from piles to the surrounding subsoil and therefore in supported, tested and practical design methods. This is particularly true when seeking to determine the unit side shear strength of shafts drilled in granular media with gravels, where it has been observed that the commonly used calculations developed for sands underestimate the load-bearing capacity by frictionin a most important way. Due to the above reasons, it seemed appropriate to present in this paper a review of the current stateof- practice in Mexico for the design of cast-in-place drilled shafts, particularly in granular media, highlighting some recent advances and research that takes into account the grain size distribution and behavior of granular soil."

Jan 1, 2014

By Rick Deschamps, Brian Barkauskas, Aled Hughes, Abigail Stein

In central Washington, six miles south of the small town of Vantage, the flow of the Columbia River is harnessed by the Wanapum Dam which is part of the Priest Rapids Hydroelectric Project owned and operated by Grant County Public Utility District (GCPUD). Extending more than 8,300-feet from bank to bank, the dam includes left and right earth embankments, left and right concrete gravity sections and a 10-unit powerhouse. Adjacent to the right embankment is a concrete gravity spillway featuring radial gates measuring 50-feet-wide and nearly 70-feet-high. In the early 1960’s when Wanapum Dam was built, these seven-story spillway gates were the highest in the world. In late February 2014, 50-years into its service life, during a routine maintenance inspection, observant workers noticed a slight misalignment in the roadway deck curbs and handrails located on top of the spillway. Further survey and inspection efforts uncovered a 65-foot-long by two- inch-wide crack that spanned the full length of Monolith 4. On discovering the extent of the damage, GCPUD initiated immediate drawdown of the reservoir to relieve pressure on the spillway monoliths. Wanapum Reservoir and the areas directly downstream of the dam were immediately closed, boat ramps and inlets were left completely dry, campsites were closed and boating activity was banned on the lake until further investigations and remedial procedures were in place and completed. An extensive root cause analysis ultimately led to the conclusion that errors in the initial design calculations and late changes to the final spillway design led to a condition that generated tensile stresses in the concrete at the upstream face, which over a period of 50-years resulted in the formation of a crack along a horizontal lift joint located about 85-feet below normal pool elevation. Further analysis showed that, although visible distress was found at Monolith 4, there was nothing preventing this issue from happening at other locations along the dam spillway. Although no visible cracking was found in the other monoliths, repair procedures for Monolith 4 would have to be replicated at the remaining monoliths.

Jan 1, 2018

By Ramdane Bahar

"Abstract The design foundations can be performed using Menard pressuremeter rules that require a limit pressure and a pressuremeter modulus. In recent years, another trend of interpretation of this test is appeared. It consists of identifying the rheological soil parameters using analytical or numerical methods and then used to evaluate the bearing capacity and settlement of soil foundations using numerical software. This paper deals with the bearing capacity and settlement predictions of bored piles using two approaches. The first one is the method called ""Pressident"" which is a numerical program developed to analyse pressuremeter tests taking into account the Duncan and Chang model. The second approach is the method developed by Bahar and Olivari based on the generalised elastoplastic Prager’s model with the Von Mises criterion which is suitable to describe the behaviour of saturated clays under undrained conditions. The pressuremeter data, collected on various research and consulting projects are used to explore the relationship between limit pressure and undrained shear strength obtained by the two methods. Numerical calculations, by FLAC2D software taking into account the rheological parameters derived from these two methods, are performed in order to predict the behaviour of a single bored pile subjected to an axial vertical load. The predictions are comparedto the measured data.IntroductionThe Menard Pressuremeter test has been used extensively to measure in situ soil properties and for the design deep foundations in Algeria. These tests are an useful and economical way for obtaining reliable in situ properties of soils and provide the measurement of in situ stress-strain response of soils. From this test, the design foundations can be performed using pressuremeter rules that require a limit pressure, pl, and a pressuremeter modulus, EM. These two parameters are derived from the pressuremeter curve or deduced from existing correlations with undrained cohesion and internal angle friction (Ménard, 1957; Amar and Jézéquel, 1972), and are used to evaluate the bearing capacity of soil foundations and the expected settlements. But, they can also help to identify usual soil parameters required by simple constitutive models for soils in numerical calculations."

Jan 1, 2014

By Hayel M. El-Naggar, Sherif A. Akl

Although grouted piles have been used for several decades since the idea was proposed in the 1970s, their design is mostly based on experience and unpublished proprietary methods. There is little research on grouting drilled shaft tips and even less on grouting shaft sides. This paper presents the analysis of 4 instrumented pile loads tests on base and shaft grouted piles from different sites in Egypt; with emphasis on one of the tests, to demonstrate the analysis process. The data from the tests are analyzed to model the development of unit side friction (USF) with relative displacement. A numerical model using the finite element software PLAXIS is used to investigate the effect of grouting on the surrounding soil stress state. The paper combines the observations from full scale pile load tests and results from the numerical model to suggest an idealized behavior of side friction development with relative displacement of the grouted part of the shaft. The suggested model considers an envelope of Unit Side Friction (USF) with relative displacement, initially dominated by the grout resistance then at higher relative displacements, the friction with radially pressured soil takes over. The grout provides very high USF values up to a relative displacement of 2mm. Then, the USF drops to a typical pile soil side friction behavior; however, this friction is affected by the contact stress between pile and soil, which significantly increases due to compaction grouting. INTRODUCTION Base and shaft pile grouting has been significantly developing in recent years to accommodate the unfavorable conditions in major projects such as the high loads in high rise building and founding on problematic soil formations. Grouting aims to decrease settlements and increase the capacity of the pile under axial load. The technique is first introduced by Kraft (1974) but gained popularity in the 1980s. Typically there are two types of grouting; compaction, and permeation. Compaction grouting is more common in pile foundations practice, and many researchers have provided case histories of pile load tests on base grouted piles and base and shaft grouted piles (Gouvenot and Gabaix,1975; Stocker, 1983; Ghazali et al., 1988; Fleming, 1993; Kusakabe et al., 1994; Robson and Wahby,1994; Joer and Randolph, 1998; Hamza and Leoni, 1998; Mullins et al. 2000; Littlechild et al., 2000; Suckling and Eager, 2001; Dapp and Mullins, 2002; Ho, 2003; Fu and Zhou, 2003; Brettmann and NeSmith, 2005; Ruiz, 2005; Mullins, 2006; Dapp and Brown, 2010; Beadman et al., 2012; Nguyen et al., 2013; Miller et al., 2013; Sinnreich and Simpson, 2015; Hui and Lin, 2015). Compaction grouting is meant to densify the soil around the pile and below the base rather than permeate this soil and increase its cohesion. Research showed that grouting increases the capacity of the piles by a factor of 2~5. The variation in capacity increase depends on pile type, grouting process, and especially grouting pressure. Although there are many case histories of pile load tests on grouted piles but there is no well-defined agreed-upon method to predict grouted pile capacity as typically done in ungrouted piles. Few lab experiments discussed the shaft grouting effects on the soil especially the compaction grouting. The experiments concluded that the compaction grouting forms a homogeneous layer between the pile and the soil, and a residual effective stress is achieved simultaneously with a significant densification of the soil around the pile with noticeable decreasing in void ratio. (Fattahpour et al., 2015; Wang et al., 2015). Recently, studies used numerical analysis to investigate the behavior of the grouted piles and the changes in the surrounding soil (Chiang et al., 2013). That study presents a simulation of the base pressure grouting with a simple FE model and predicts the reduction of the pile settlement by 10 to 20%. Another numerical study using a complex model conducted by Zhou et al. (2017), pr

Jan 1, 2018

By Y. X. Tong

The simplicity off Ø=0 analysis has been taken advantage of to evaluate the geotech­nical problems of open caissons, slurry trench walls and piles in Shanghai. Undrained shear strengths obtained by various testing methods are correlated with case record and experimental data. Some problems posed by the construction of tall buildings are briefly discussed. Comments on applications are made to help engineers deal with practical problems.

Jan 1, 2010

By David G. Winter

The first test pile for the carrier pier and south wharf at NAVSTA Puget Sound was driven on December 27, 1989, and the final pile was tested on February 26, 1990. Implementation and modification of the test pile program were done by the owners (WESTDIV and ROICC-Everett), the engineers (ABAM and Hart Crowser), and the contractor and his subcontractor (General Manson Joint Venture and GRL). The site is located as shown on Figure 1. SUMMARY OF THE SOIL CONDITIONS A soil profile along the pier is shown as Figure 2. The soil units can be generalized as follows: ? Upper Silts - Fill, sandy silt, and clayey silt extending from the mudline to an elevation of about -80 feet; ? Intermediate Sand - A medium dense to very dense silty sand unit which is about 30 feet thick near the shore, but thins and disappears offshore; ? Lower Silts - Sandy silts and clayey silts in a medium stiff to stiff condition; ? Deep Sand - A very dense overconsolidated sandy soil encountered at an elevation of about -145 feet.

Jan 1, 1990