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By B. B. Broms

A method for calculating the bending moment induced in misaligned or bent piles is described, The maximum bending moment varies with the angular rotation between the pile segments, the coefficient of horizontal subgrade reaction of the soil and the flexural rigidity of the piles. A case history involving damages to misaligned 365 x 365 mm square precast concrete piles is described.

Jan 1, 2010

By S. X. Liang

In China, the bearing capacity predictions of the pile with Stress-Wave Theory have been developed rapidly in recent years. This paper recommended a DZH-3 Pile Driving Analyzer and its relevant computer programs. Taking Qinghai Hotel Project for example, it gave their applications in the dynamic tests of large diameter cast-in-place piles.

Jan 1, 2010

By Y. G. Qin

In this article an experimental study of axial bearing capacity of half-closed steel pipe pile installed at BKSH dock is presented. In comparison with open and closed end piles, half-closed end pile is considered to have high bearing capacity and good penetration, that is, it not only has a capacity as twice as the same size open end steel pipe pile, but also has blow counts as half as the same size closed end steel pipe pile. It is economic to use half-closed end pile in soft ground without a deep deposit of thick stiff clay. This article also describes a large scale model pile test and preliminarily analyses mechanism of improvement of bearing capacity of half-closed end pile with emphasis on effect of squeezed soil on side friction; an empirical approach is presented in which side friction is related to density of squeezed soil and which is useful for reasonably chosing side friction of different types of piles in design of foundarion.

Jan 1, 2010

By R. A. Fraser

Large diameter (1.0 to 2.5m) bored piles have been widely used to support buildings and elevated roadways in Hong Kong. Most of these piles are founded on a hard bearing stratum such as granitic or volcanic bedrock, in the newly reclaimed areas along the water-front, the bedrock stratum can be as deep as 70-80 metres below ground surface, and construction of bored piles to bedrock in this case is difficult and unjustified. Nevertheless, Building Ordinance Regulations in Hong Kong require piles to be founded on bedrock. To overcome this problem for elevated roadways, trial piles have been designed founded on dense, completely decomposed granite. A number of piles have been constructed and subsequently load-tested to allow the rate of mobilisation of skin friction to be measured. This paper outlines the design, construction and testing method, and comments on the test results from several trial piles. GEOLOCICAL CONDITIONS The geology of Hong Kong consists predominantly of acid volcanic rocks intruded by granite. The granite has been deeply weathered, and variations in sea level have produced a drowned coastline with sequences of alluvial, colluvial and marine deposits overlying the weathered bedrock. Reclamation has extended this coastline. Typical site conditions are described later in the paper.

Jan 1, 2010

By T. Matsui

Many existing bridge abutments on the soft ground laterally move and their many damage examples have been reported. An essential cause for the troubles of the lateral movements may be the lack of examinations for the lateral earth pressure acting on its foundation piles. In the present paper, actual movement condition of existing bridge abutments is first summarized, and then the author establishes a practical and systematical design method for bridge abutment foundation piles, including the examination for the passive pile.

Jan 1, 2010

By A. Tejchman

On the site of building of a new flyover founded on piles the comprehensive "in situ" investigations were carried out. The subsoil conditions under each of 15 supports were very differentiated. Using of the static sounding results a new method for evaluation of bearing capacity and settlement of piles was proposed. The method is based on a special construction of the curve of load-settlement relationship. The verification of this method was made on the basis of loading of piles.

Jan 1, 2010

By Z. Q. Bian

The wireline sampling originates from core drilling in rocks. The authors combined the wireline sampling technique with conventional undisturbed soil samplers, including Osterberg sampler, Denison sampler and double tube barrel, and then developed the wireline samplers of WPS, WSS and WSR models. These samplers are able to sample various soils. They reserve all the advantages of the original samplers, and moreover, they are noted with quick hoisting and lowering by wire rope. Therefore, it becomes an efficient new technique of sampling undisturbed soil from deep foundation.

Jan 1, 2010

By C. W. Sheng

In this paper conventional construction procedure is briefly described for the installation of stone columns in soft ground in China. A viewpoint concerning the mechanism of ground improvement by use of stone columns is presented for discussion. Based on the information obtained from field measurement and observation three important problems relating to the construction and design of stone columns are discussed. Finally, a case history is given to show that short stone columns floating within the weak soil layers may in some instance be used to improve the weak strata of great thickness.

Jan 1, 2010

By R. J. Yan

There was a plant equipped with a 32000t Hydraulic Press to be built, under which a box foundation of 22.5m x 15m x 14.25m (depth) with a base slab of, varying thickness was proposed. The subgrade reactions, bending moments and settlements needed to be determined by means of in-situ model test. A model of the same materials as the prototype scaled to l/10 was embedded in-situ with simulated depth in the bedrock. A lot of data obtained from 39 bench marks, 32 elongation measuring points, 30 couples of electric resistance strain gauges and 24 pressure cells attached to the model foundation enables all the quantities required to be found out. Since it was put into operation, the settlements measured has reasonably agreed with the test results and the foundation has been in good condition.

Jan 1, 2010

By J. K. Mitchell

Soil improvement is examined within the context of the characteristics of different soil types, the types of ground improvement techniques that can be used to improve them, and the level of improvements that might be achieved. Several case histories are described to show how the particular soil and foundation characteristics influence the choice and success of different ground improvement techniques. Although the basic methods for soil improvement have been known for many centuries, there have been significant recent advances in the technology for their use. Time effects following the densification of cohesionless soils may lead to significant improvements in strength and stiffness. Unanticipated chemical reactions may follow stabilization using admixtures when soils for which there has been little prior experience are encountered. In some cases foundations that combine features of both ground improvement and deep foundation systems may provide good performance at reasonable cost.

Jan 1, 2010

By A. F. Deng

A general description of the project, mainly the pier foundation design of the ZHU JIANG FANYING is presented in the paper. The major contents include the foundation scheme, the evaluation of bed-rock characteristics, the allowable bearing pressure, the design and construction of pier foundation.

Jan 1, 2010

By M. Nomura

This paper describes the results and field measurements of two long-term observation tests and two short-term loading tests to confirm the effectiveness of NF piles in reducing negative skin friction. All the test piles were equipped with strain gauges, allowing measurement of the compressive axial forces in the piles. These test results prove that NF piles are effective in reducing the negative skin friction to an insignificant value. Some examples of the design procedures used in Hong Kong and Japan are also presented.

Jan 1, 2010

By Mohammad Eslami

The Tabriz-Urmiyeh Highway shortens the distance of north-western cities of Iran by about 130 km, resulting in improved access and efficient transit between Iran and Europe through Turkey. The highway crosses the Urmiyeh Lake, an inland lake surrounded by mountains. Due to the circulation of salt-water in the lake and the necessity to continue shipping between adjacent ports, a waterway should be kept open. Consequently, a bridge was built to provide access of marine traffic. A causeway bridge had a length of 1,260 m, comprising of 19 spans. In construction of the bridge, more than 400 piles having a total length of 32 km have been driven. For design of piles different methods have been used such as static analysis, dynamic testing, and correlations to in situ tests, such as cone penetration test (CPT). This paper presents construction of bridge substructure, full-scale piling tests, and methods of analysis used in the evaluation of the deep foundation capacity. The presentation includes an assessment of four current direct CPT and one CPTu methods to calculate the bearing capacity of the piles. It was found that the CPTu and dynamic testing are two suitable tools for rapid and optimum pile design and verification.

Jan 1, 2010

By K. E. Darnell

Drilled pier foundations have long been a favored foundation type for heavily loaded structures. Drilled piers derive their load-bearing capacity from end-bearing, and/or sidewall friction. This type of foundation is used in many geologic settings, including those areas underlain by hard carbonate rock, such as limestones and dolomites. When properly designed and constructed, drilled piers provide high load-carrying capacity in both compression and uplift. However, carbonate rock is often subject to intense differential weathering resulting in the formation of an irregular bedrock surface, sinkholes and caves; consequently, the investigation for, and the design of, drilled pier foundations is often complex. Further, the construction may be difficult and costly. This paper discusses geotechnical investigative procedures which can be employed to develop foundation design criteria and reduce the frequency of changed conditions. Finally, state-of-the-art construction practices and quality control techniques are discussed.

Jan 1, 2010

By P. Dupeuble

Diaphragm walls, owing to their method of construction are discontinuous structures. A new technology for the construction of joints between panels has been developed. This new process allows for the construction of diaphragm walls with mechanical and watertight continuity.

Jan 1, 2010

By J. M. Mitchell

Kuala Lumpur, Malaysia is underlain by karstic limestone. Firm clays, mudstones and siltstoncs of the Kenny Hill Formation overlie the limestone for about two thirds of the city. The remaining third has deep deposits of very soft alluvium, or tin mining slimes, overlying the limestone. It is only recently that large buildings have been constructed in the area. Arup Jururunding have been concerned with several projects located on the limestone, although space here only permits the description of four sites in detail. The experience has allowed the development of a design approach for the foundations. The aim is to make the architectural scheme compatible with the geology. This is not always possible, and examples are given of both situations. The case histories give examples of compensated foundations, and piled foundations include steel H-piles, precast concrete piles, micropiles, bored piles with rock sockets, and barrettes up to 90m deep.

Jan 1, 2010

By W. Lum

In the U.S., flexible metal pipe culverts are designed by ring compression theory because the pipes are capable of deflecting and deriving side support from surrounding ground. For economy, tunnel liners are often designed as flexible structures that depend on the lateral pressure of the surrounding ground to maintain stability. In this paper, simple formulas are presented to determine the maximum deflection a concrete tunnel liner may assume and the ring compressive strength of the deflected liner. A tunnel can then be constructed to work within these limits. Similar techniques may be used to design concrete pipes.

Jan 1, 2010

By P. J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 2010

By G. X. Zeng

A calculation programme of finite element method has been developed in order to study the behavior of excavation with sheet piling in soft clay. Based on a series of isotropically consolidated-undrained tests (CIU) on Hangzhou clay a linear relationship between the normalized initial tangent modulus number, E1, and stress-path parameter, a, is found for four different stress paths, and stress-path dependent modulus equations derived. Meanwhile, several influence factors, such as embedment depth and stiffness of the wall and soil conditions, were taken into consideration in the programme. Some valuable conclusions were obtained. Finally, a case history was studied by the proposed method of calculation. The result of calculation and the field observation are in good agreement.

Jan 1, 2010

By Steven L. Anderson

A cut-off wall has been designed and is currently under construction along the Back Dam of the existing tailings impoundment at Red Dog Mine, Alaska. The cut-off wall, which will be in the order of 5,000 ft long and up to 150 ft deep, when complete, is being excavated using a 40 metric ton Bauer trench cutter head mounted on a Liebherr crawler crane, in combination with a closed loop slurry pumping and de-sanding system. The tailings impoundment is situated in an area of warm permafrost and high potential seismic activity. Design incorporated an assessment of rock jointing to define the final depth of the wall along the alignment requiring the use of plastic concrete backfill to address the concerns associated with potential cracking of the wall due to settlement and during seismic activity. The results of the geotechnical investigation program, particularly with respect to variation in rock hardness along the wall alignment are discussed, as are the design criteria for the plastic concrete backfill, the challenges faced during construction, including scheduling of the work with the on-going dam raise activities of the mine, and the lessons learned with respect to potential productivities and selection of cutter wheels and teeth. Also described are the requirements for and advantages of utilizing a slurry boosting system to meet pumping requirements, re-design of the plastic concrete mix to consider workability and optimization of cutter teeth configurations to reduce wear through highly varied rock hardness.

Jan 1, 2010