摘要:

A new procedure for the design of drilled piers socketed into soft rock is presented and the selection of design parameters discussed. The design method is based on (1) satisfying a specified design settlement criterion and (2) checking to ensure that there is an adequate factor of safety against collapse. The design allows consideration of the possibility of some slip occurring at the pier–rock interface under working load conditions.The design procedure is illustrated by a series of detailed calculations relating to two piers in Queenston shale and the observed behaviour of these piers is compared with design expectations. It is shown that these piers satisfied the design settlement criterion while having a significant proven factor of safety against collapse.Key words: rock, piers, piles, settlement, bearing capacity, design.

ISSN:0008-3674    

DOI:10.1139/t87-011

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

Based on the Boussinesq formula, exact formulae are derived for the vertical stress beneath the corner of an arbitrarily shaped triangular surface region subjected to vertical pressures with a uniform, linear, or quadratic distribution. These formulae are the basis of a proposed analysis technique in which any arbitrarily shaped loading region is approximated by a set of triangular regions. Computer algorithms that take advantage of the highly repetitive, yet simple, mathematical operations can readily be implemented on the computational facilities currently available to most engineers.Key words: triangular or arbitrarily shaped load regions, vertical stress distribution, computer solution.

ISSN:0008-3674    

DOI:10.1139/t87-012

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

The lateral soil pressure distribution, pile capacity, and displacements of instrumented single rigid bored piles subjected to pure moment and horizontal load have been investigated. The influence of method of pile installation on the above parameters is studied by comparing the behaviour of bored piles with that of jacked piles. It was concluded that the method of installation has practically no effect so far as the net lateral soil pressures and pile capacity are concerned, but the displacements may be up to three times larger for a bored pile than for a jacked pile under working loads.Key words: clay, horizontal load, installation, model test, moment, pile.

ISSN:0008-3674    

DOI:10.1139/t87-013

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

Groups of piles provided to support tall structures such as transmission towers, chimneys, stacks, etc. are subjected to pullout forces. The uplift capacity of a single pile in clay or sand can be estimated rationally and reliably by methods available. In this note, the interaction between two identical piles in tension is studied by modelling the soil as a homogenous, linearly elastic medium and by using the boundary integral technique. The reduction in individual pile capacity due to the existence of another pile is quantified and found to depend on the spacing and length-to-diameter ratio of the pile, and the type of variation with depth of pile-soil interface strength. Efficiencies of typical pile groups are computed. The predictions compare well with model and full-scale test results.Key words: axial capacity, boundary element method, efficiency, groups, interaction, piles, uplift.

ISSN:0008-3674    

DOI:10.1139/t87-014

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

A study was performed in the shallow waters of the MacKenzie Delta area near Tuktoyaktuk, N.W.T., Canada, to evaluate equipment, test procedures, and techniques using a seismic cone penetrometer and operating on the landfast ice in winter. Seismic cone penetration testing was performed to determine the compressional and shear wave velocities of the subsurface sediments using a downhole technique. Several seismic sources and receivers were tested to evaluate their effectiveness. Typical results are presented and briefly discussed.Key words: downhole, seismic, P-wave, S-wave, velocity,in situ, measurement, shallow offshore, cone penetration test.

ISSN:0008-3674    

DOI:10.1139/t87-015

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

A two-pronged metal probe measures the thermal conductivity and apparent dielectric constant of soils in the laboratory and in the field. One prong acts as a transient line heat source probe in measuring thermal conductivity. The apparent dielectric constant of the soil is determined by the time-domain reflectometry (TDR) technique, using both prongs as a parallel transmission line. Volumetric water content is determined from the apparent dielectric constant, making use of an empirical relation valid for most soils. For volumetric water contents above about 8%, the apparent dielectric constant shows a strong dependence on water content and relatively small changes can be measured; sensitivity increases with water content. For volumetric water contents less than 8%, a soil-dependent empirical relation between water content and thermal conductivity has been developed that is most sensitive at lower water contents. The combined probe provides a means of monitoring the water content of soils over a wide range of values, in the field and in the laboratory.Key words: soil water content, time-domain reflectometry, thermal conductivity.

ISSN:0008-3674    

DOI:10.1139/t87-016

出版商:NRC Research Press    

年代:1987

数据来源: NRC

摘要:

The lower block of the Denholm landslide has moved 370 m over alluvium deposited by the North Saskatchewan spillway and river during the last 11 500 years at an average rate of 32 mm/year. These values must be considered minimal because erosion of the toe of the landslide is required for the formation of retrogressive landslides. The shear strength for the bedrock clay (shale) of the Lea Park Formation was back calculated to beassuming zero cohesion.Key words: retrogressive landslide, clay shale, residual strength, movement rates, geological age, inclinometer.

ISSN:0008-3674    

DOI:10.1139/t87-017

出版商:NRC Research Press    

年代:1987

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t87-019

出版商:NRC Research Press    

年代:1987

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t87-020

出版商:NRC Research Press    

年代:1987

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t87-021

出版商:NRC Research Press    

年代:1987

数据来源: NRC