Static Cone Penetration Test Research Articles

Rules and Regulations Regarding Use of Static Cone Penetration Testing on Permafrost in Newly Issued Building Code 25.13330.2102

Basic positions of Building Code 25.13330.2012 on static cone penetration testing of frozen soils are presented and commented upon. The history of the appearance and development of domestic norms in the field of static cone penetration of permafrost soils is briefly analyzed.

Exploration of Determining the Bearing Capacity of Calcareous Concretion Soil with Static Cone Penetration

Cohesive soil containing calcareous nodule in Huaibei plain is a kind of regional special soil, which has a unique material composition and structure. The paper discusses the types and distribution of calcareous concretion in soil, and the influence on the strength of soil and the engineering property. Through a lot of the load test and the corresponding static cone penetration test, analyzing the correlation between them.Then linear regression equation between and is established. Finally, it is show that linear regression effect is remarkable, and the equation can be reference for the local practical engineering

Near Surface Research and Excitation Horizon Prediction Based on Old River Course of Xiaoqing River in Shan Dong

Following deepened exploration and development in Shengli exploration area, seismic data requirements are also getting higher and higher. However, in recent years the difference of Xiaoqing river on both sides have made us know that the importance of this problem. In view of the above, this task is aimed at quaternary shallow of old river course within Xiaoqing River. Our analysis of lithology and sedimentary characteristics are using static cone penetration test and rock core exploration method, and we want to reappear near surface deposition of old river course within Xiaoqing River. The research is close combined with the exploration demand and theoretical study, so it has important theoretical and practical significance.

Energy Transfer Measuring in Dynamic Probing Test in Layered Geological Strata

Static and dynamic probes are commonly used performing engineering geological investigations in Lithuania. Due to their peculiarities, static cone penetration tests (CPTu) are most suitable for penetration of relatively weak soils. In case of deeper soil layers covered with strong soils was investigated Dynamic penetration test (DPT) is the only that could be used. In Lithuania, the most common bearing strata of foundation are glacigenic and alluvial deposits of Pleistocene age. Geotechnical properties of separate strata may differ significantly. Despite the fact, that the dynamic probing is a relatively cheap comparing with CPT investigation method, it has some significant disadvantages. The main disadvantage of reliability of DPT test results is related with transfer of driving energy through the drive rods to the cone tip. Three tests with attached sensors to the rod were performed in layered geological strata to obtain energy transfer parameters. CPT test was done after DPT for obtaining soil stratification and geotechnical soil properties promiscuity at a distance of 1.5 m. The field tests were performed at a site that is located in northeast part of Vilnius, near the complex of buildings of Vilnius Gediminas Technical University in Saulėtekis district. From geological point of view this part of Vilnius is stratified of glacigenic deposits.

The Consolidation State of Red Clay Determined by Cone Penetration Test

It is of significance to determinate the consolidation state of soil for evaluation of deformation and strength of foundation soil. The consolidation state of red clay is determined through laboratory experiments combined with static cone penetration tests. The results show that the law of consolidation history of red clay is opposite to other soils. The static point resistance obtained from cone penetration test decreases linearly with soil depth increasing. The over-consolidate rate of different soil layer gotten by laboratory experiments also decreases linearly with soil depth increasing. The slopes of two linear regress curves are similar. The change of static point resistance can be used to estimate over-consolidate rate of red clay at different depth.

Effect of driving long pre-stressed high-strength concrete pipe piles in alluvium and its mechanical behavior

To investigate the driving effect of long pre-stressed high-strength concrete (PHC) pipe piles on surrounding cohesive soil layers and mixed soil layers, standard penetration tests and static cone penetration tests were performed. Pore water pressure, lateral displacement in the surrounding soils and shaft forces along the piles were also measured. The process of driving piles was recorded and the mechanical behavior of the piles was researched using fibre optic sensors as well. The results indicated that significant excess pore pressure and lateral deformation were developed as the result of the pile driving and their magnitudes decreased with distance from the pile. Pile driving improved the mechanical properties of the surrounding soils and enhanced the liquefaction resistance of both the silt and silty sand layers. The ratio of soil plug length to pile length ranged from 22 to 43 % and the PHC pile with a thinner wall resulted in a greater plug. The distribution of the shaft force was nonlinear along the pile length and became more obvious with the increase of the applied load. Shaft resistance varied with the magnitude of applied load and the soil properties.

Practice Research on Wet-Collapsible Loess Foundation Treatment by High Energy Dynamic Compaction

A systematic and comprehensive study on the design, construction and testing of large scale of Ⅲ～Ⅳ grade wet-collapsible loess foundation treatment by 8000 kN•m high energy dynamic compaction is done in this paper. Effect on the treatment for collapsible loess foundation by dynamic compaction is analyzed through Rayleigh wave velocity test, standard penetration test, lab soil test and static cone penetration test. By comparison with physical and mechanical properties index of the foundation soil without dynamic compaction treatment, the effective reinforcement depth, the elimination of collapsibility and the bearing capacity of foundation are found to meet the design requirements. The results of this paper could supply some reference for the design, construction and testing of other collapsible loess foundations by dynamic compaction treatment.

Experimental Study on Dynamic Consolidation Method to Improve Saturated Soft Soil Foundation

A new technology of dynamic compaction method is successfully used to reinforce the saturated soft soil foundation. The field monitoring laws of lateral displacement of the foundation after dynamic compaction, the increasing and dissipation regularity of the excess pore water pressure are analyzed and discussed. The improvement effect is verified by static cone penetration test and loading test. The determination methods of effective reinforcement depth after dynamic compaction are put forward. The practice shows that, by field-testing methods, such as static cone penetration test and pore water piezometer test, to determine the effective reinforcement depth after dynamic compaction and other design parameters is reliable.

An electrical resistivity imaging-based strategy to enable site-scale planning over covered palaeokarst features in the Tournaisis area (Belgium)

Since the beginning of the 20th century, more than 150 sinkhole occurrences, mainly dropout (or cover-collapse) sinkholes, have been reported in the Tournaisis area (south-eastern Belgium). Land-use planning in such a context has to take into account hazards linked with sinkhole subsidence and collapse. Management maps, drawn at a regional scale, point out zones where karstic risks have to be taken into account when dealing with infrastructure or building projects. However, karst hazard is highly variable in three dimensions at the local scale. Therefore, for such purposes, an accurate methodology is needed to detect and delineate covered karst features, especially when located in urbanized areas.As geophysical investigations are sensitive to contrasts in physical properties of soils, these methods can be useful to detect such targets. The specific karstic context encountered in the Tournaisis area strongly guides the choice of investigation techniques. Electrical resistivity imaging (ERI) methods were tested on a well-known site where dropout sinkholes occurred formerly. This site was also studied using static cone penetration tests (CPT) and boreholes. A 3D inverted resistivity model was computed based on the 2D ERI models obtained after inversion. Resistivity profiles were extracted at each CPT location and compared to geotechnical results to determine an empirical and site-specific resistivity law that allows discrimination between weathered zones and sound limestone. Performance tests were conducted to evaluate the potential of the proposed methodology for two typical engineering problems based on two current hypotheses. Borehole data were used as ground truth. Similar performance tests were also computed using the CPT depth to bedrock model. The results of these performance tests are compared and discussed. Finally, an ERI-based investigation strategy is proposed to assess karst hazard in palaeokarstic context, such as encountered in the Tournaisis area, at the scale needed for building and infrastructure purposes.

Effects of Foundation Pit Dewatering on Load-bearing Capacity of Soil Body around the Pit

It is proved that pit safety has a close relationship with foundation pit dewatering.In order to find out the relationship between foundation pit dewatering and load-bearing capacity of soil body around the pit,a vast amount of original position monitoring work has been engaged.Based on the groundwater level monitoring data,load tests by pressure bearing plate,and static cone penetration test,the empirical mathematic models of the variations of groundwater level and load-bearing capacity of soil body around the pit were set up after foundation pit dewatering.The model construction process as well as application effects have been introduced in our paper.

Dynamic Consolidation Test Study on Silt and Silt Soil

A dynamic consolidation model of double layered foundation of saturated soil and unsaturated soil is proposed. Mechanism of dynamic compaction treating on double layered foundation is studied by the model. On the base of the mechanism a new technology called soil-mound dynamic consolidation can be applied to treat the ground of saturated silt and silty clay with high groundwater level. The water-pore pressure test, static cone penetration test, settlement plate test are applied to evaluate that of the new technology with different construction parameters. The treatment effect is more remarkable than that of plastic drain-dynamic consolidation.

Experimental research on the marine hydrodynamic action on the consolidation process of the sediments in the Yellow River Estuary

Based on the in-situ measurements, the impact of the marine hydrodynamics, such as wave and tide, in the rapidly deposited sediments consolidation process was studied. In the tide flat of Diaokou delta-lobe, one 2 m×1m×1 m test pit was excavated. The seabed soils were dug and dehydrated, and then the powder of the soil was mixed with seawater to be fluid sediments. And an iron plate covered part of the test pit to cut off the effect of the marine hydrodynamics. By field-testing methods, like static cone penetration test (SPT) and vane shear test (VST), the variation of strength is measured as a function of time, and the marine hydrodynamics impact on the consolidation process of the sediments in the Yellow River estuary was studied. It is shown that the self-consolidated sediments’ strength linearly increases with the depth. In the consolidation process, in the initial, marine hydrodynamics play a decisive role, about 1.5 times as much as self-consolidated in raising the strength of the sea-bed soils, and with the extension of the depth the role of the hydrodynamics is reduced. In the continuation of the consolidation process, the trend of the surface sediments increased-strength gradually slows down under the water dynamics, while the sediments below 50 cm are in opposite ways. As a result, the rapidly deposited silt presents a nonuniform consolidation state, and the crust gradually forms. The results have been referenced in studying the role of the hydrodynamics in the soil consolidation process.

Reliability-based pile design in sandy soils by CPT measurements

Field tests, such as static cone penetration tests (CPT), are widely used in granular soil characterisation because they are largely correlated by empirical charts and graphics to the main physical and mechanical soil properties (i.e. DR, φ, lithology etc.), although the uncertainties concerning with such estimations are taken into account. Whereas those formulations are widely accepted by literature and used in practice, they are not discussed in terms of reliability level of the pile bearing capacity. In this paper, Bustamante and Gianeselli's formulation has been adopted as a direct method for estimating pile bearing capacity from qc profile at Scanzano Jonico site. As far as the reliability-based design of limit pile resistance is concerned, the statistical properties of the design variables are based on the variability study carried out on such sand. Results are discussed with respect to the advantages in usage of direct instead of indirect methods for pile design in sand.

Effect of soil variability on the bearing capacity of clay and in slope stability problems

Site-specific geotechnical data are always random and variable in space. In the present study, a procedure for quantifying the variability in geotechnical characterization and design parameters is discussed using the site-specific cone tip resistance data ( q c) obtained from static cone penetration test (SCPT). The parameters for the spatial variability modeling of geotechnical parameters i.e. ( i) existing trend function in the in situ q c data; ( ii) second moment statistics i.e. analysis of mean, variance, and auto-correlation structure of the soil strength and stiffness parameters; and ( iii) inputs from the spatial correlation analysis, are utilized in the numerical modeling procedures using the finite difference numerical code FLAC 5.0. The influence of consideration of spatially variable soil parameters on the reliability-based geotechnical deign is studied for the two cases i.e. ( a) bearing capacity analysis of a shallow foundation resting on a clayey soil, and ( b) analysis of stability and deformation pattern of a cohesive-frictional soil slope. The study highlights the procedure for conducting a site-specific study using field test data such as SCPT in geotechnical analysis and demonstrates that a few additional computations involving soil variability provide a better insight into the role of variability in designs.

Reliability analysis of the bearing capacity of a shallow foundation resting on cohesive soil

In recent years, there have been considerable advances in the characterization of soil variability and its application in geotechnical designs. It is recognized that in using reliability-based design it is necessary to consider all sources of uncertainty in the analysis and incorporate them in the geotechnical design. It is also necessary to examine the reliability-based approach in relation to deterministic approaches. In this study, cone tip resistance (qc) data obtained from a static cone penetration test on a stiff clay deposit are analyzed by using random field theory; and statistical parameters, such as the mean, variance, and autocorrelation function, are estimated in evaluating the reliability of the allowable bearing capacity of a strip footing founded on the above deposit.Key words: reliability-based design, soil variability, random field, variance, autocorrelation function, bearing capacity.

Liquefaction-Induced Lateral Spreading at Izmit Bay During the Kocaeli (Izmit)-Turkey Earthquake

This paper presents a study of liquefaction-induced lateral ground displacements along the coast of Izmit Bay during the 1999 Kocaeli (Izmit)-Turkey earthquake. The paper discusses: (1) observed ground displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests, including standard penetration tests, static cone penetration tests, and piezocone tests, (3) analyses of expected lateral displacements using two empirical models and one semiempirical model, and (4) comparisons between observed and calculated lateral ground movements. The three models provide inconsistent predictions of observed lateral ground displacements, with one method overpredicting and two methods both overpredicting and underpredicting observed lateral ground displacements by large amounts. Thus, it appears that there is a need for improved engineering tools for prediction of small to moderately significant lateral ground displacements (lateral displacements of approximately 0.1–2.5 m) at soil sites with similar ground characteristics to the case history sites presented herein.

Cone Resistance of Compacted Ash Fill

Abstract Coal ash is a granular byproduct of the combustion of coal in coal-fired thermal power plants. The compacted ash is frequently used as a structural fill material. Standard geotechnical investigation methods used for natural soils have revealed inconsistencies when extended to ash fills. The characterization of ash shows morphological dissimilarity with natural soils. It is observed that several groupings of in situ density and stress level lead to similar penetration resistance in coal ash. Thus, the correlations reliable for soils may have questionable interpretations of blow count or measured cone resistance in coal ash. The static cone penetration test results analyzed at various combinations of stress level and relative density indicated the need for a new scheme for interpretation of behavior of ash fills on the basis of relative dilatancy of the ash. The resistance to penetration of the standard cone was interpreted at varying depths on ash fill compacted at varying relative densities. Correlations are suggested to estimate bearing capacity and settlement characteristics of coal ash on the basis of cone penetration test results for direct geotechnical design.

Seismically induced landslide at Degirmendere Nose, Izmit Bay during Kocaeli (Izmit)-Turkey earthquake

This paper presents a study on the analyses of seismically induced landslide at Degirmendere Nose during the 1999 Kocaeli (Izmit)-Turkey earthquake. The paper discusses: (1) observed ground deformations and displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests including standard penetration tests, static cone penetration tests (CPT) and piezocone tests, (3) analyses of observed landslide mechanisms by a suite of methods and (4) potential effects of soil liquefaction rupture on the observed landslide mechanism.

Viscous behaviour of St-Roch-de-l'Achigan clay, Quebec

This paper describes the viscous behaviour of St-Roch-de-l'Achigan clay, a Champlain Sea clay from Quebec, Canada. The general geotechnical profile of the soil deposit was first established with static cone penetration tests, vane tests, and some laboratory tests performed at different depths. For the study of the viscous behaviour of the clay, a special laboratory test program was established for specimens taken at depths from 4.8 to 5.8 m. This program included special incremental loading oedometer tests, constant rate of strain (CRS) oedometer tests performed at different strain rates, isotropic and anisotropic triaxial compression tests, and undrained shear tests. All these tests were performed under a constant temperature, varying from 10 to 50 °C. The test results show that the vertical yield stresses and the entire limit state curve depend on strain rate and temperature. The critical state line is also temperature dependent in the void ratio (e) – log principal effective stress (p′) diagram but not in the deviator stress (q) – principal effective stress (p′) diagram. The results also show that microstructuring may develop when the temperature is high or the strain rate small.Key words: viscosity, strain rate, temperature, laboratory tests.

Liquefaction-induced ground deformations at Hotel Sapanca during Kocaeli (Izmit),Turkey earthquake

This paper presents a study of liquefaction-induced ground deformations at the Hotel Sapanca site during the 1999 Kocaeli (Izmit)—Turkey earthquake. The paper discusses: (1) observed ground deformations and displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests including standard penetration tests (SPT), static cone penetration tests (CPT) and piezocone (CPTU) tests, (3) analyses of observed ground settlements and lateral deformations by a suite of methods, and (4) comparisons of observed and calculated ground movements.