scholarly journals Instrumented Impact Cone Penetrometer

1973 ◽  
Vol 10 (3) ◽  
pp. 397-409 ◽  
Author(s):  
Umesh Dayal ◽  
John H. Allen
Keyword(s):  
Field Tests ◽  
Strength Properties ◽  
Experimental Program ◽  
Cone Penetrometer ◽  
Test Results ◽  
In Situ Testing ◽  
Penetration Mechanism ◽  
Side Friction ◽  
Local Side

The present paper describes the development of an instrumented impact cone penetrometer for a direct measurement of in situ strength properties of a soil target. The developed penetrometer, in addition to providing acceleration signatures (as obtained by previous investigators), is capable of recording cone thrust and local side friction simultaneously and continuously. The procedures have been outlined for estimating in situ strength properties and soil type of the target materials throughout the penetrated depth from the output records of these sensors. Typical test results generated from an on-going experimental program aimed at providing the data for (1) understanding the penetration mechanism, (2) development of penetration theory, and (3) designing the penetrometer for field tests, i.e. in situ testing of ocean floor soils, are also presented.

scholarly journals In Situ Testing of Square Footing Resting on Geobelt-Reinforced Gravel Thin Cushion on Soft Silt

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wei Zhang ◽  
David Du ◽  
Xiaohong Bai
Keyword(s):  
Pressure Distribution ◽  
Width Ratio ◽  
Test Results ◽  
In Situ Testing ◽  
Square Footing ◽  
Stress Diffusion ◽  
Loading Tests ◽  
Vertical Spacing ◽  
Saddle Shape

A series of in situ static loading tests of square footing were carried out on the geobelt-reinforced gravel cushion on soft silt. The reinforced gravel cushion was thin with the depth-to-width ratio of 0.2. A parameters study was conducted by considering the number of geobelt layers, the depth of the first geobelt layer beneath the footing, the vertical spacing between two geobelt layers, the linear density of reinforcement, and the material type of geobelt. The pressure distribution on bottom of the cushion was measured. The test results showed that the bearing capacity of reinforced gravel cushion was significantly larger than that of unreinforced gravel cushion, and the stress diffusion effect of reinforced gravel cushion was also more pronounced than that of the unreinforced cushion. The pressure distribution on bottom of reinforced gravel cushion was in a saddle shape. According to calculation and analysis, the stress diffusion angles of reinforced cushions were all larger than 20°.

Monitoring wells: measurement of permeability with minimal modification of groundwater

1991 ◽  
Vol 18 (5) ◽  
pp. 871-875 ◽  
Author(s):  
Robert P. Chapuis ◽  
Gilles Wendling
Keyword(s):  
Water Pressure ◽  
Field Tests ◽  
Test Results ◽  
Permeability Test ◽  
Monitoring Wells ◽  
Monitoring Well ◽  
Quality Water ◽  
Check Test ◽  
Minimal Modification

It is important to verify whether a monitoring well has been correctly sealed in the ground in order to avoid vertical cross-communication between aquifers and thus prevent misleading results for the piezometric level and the degree of contamination. This may be done with an in situ falling-head permeability test. A monitoring well is used to sample groundwater, so it is not recommended to introduce a different quality water to perform the permeability check test. The test should be performed preferably with the local groundwater. A method is described in which a stainless steel and teflon bladder pump, a packer, a water pressure transducer, and a field computer are used to perform a falling-head permeability test. Many test results can be stored in the field computer before transferring its data into a microcomputer. The results may then be presented in the form of tables and graphics to determine the hydraulic conductivity of the tested layer, and to verify whether the installation of the monitoring well is correct. Results of field tests are presented to illustrate this method. Key words: groundwater, contamination, permeability, monitoring.

scholarly journals Overconsolidation Ratio Determination of Cohesive Soil

2016 ◽  
Author(s):  
Donatas Urbaitis ◽  
Ieva Lekstutytė ◽  
Domas Gribulis
Keyword(s):  
Seismic Waves ◽  
Field Tests ◽  
Cohesive Soil ◽  
Strength Properties ◽  
Overconsolidation Ratio ◽  
In Situ Conditions ◽  
Ratio Determination ◽  
Penetration Data

In order to evaluate overconsolidation ratio (OCR) of soil, the necessity to restore them as much as possible to in situ conditions appears, because sometimes when it is not taken into account, mistakes could be made while interpreting mechanical – strength properties of the soil. According to the work purpose, overconsolidation ratio of the investigated soil was set by performing odometer test and the obtained values were compared with the OCR calculated from cone and seismic penetration data. When the tests were performed and data analysed, it was found that OCR values depends on soil occurance depth, strength characteristics and stress conditions. The OCR values decreases with the declination of the depth. As many authors noted in the literature – the upper part of the soil is consolidated abnormally, thereby we can see that in our work. When results are evaluate, we can conclude that all of the analysed soils was overconsolidation. That was demonstrated by calculations according static penetration, oedometer test and seismic waves results. OCR values differences between the laboratory and field tests can show low quality of soil sampling, also due to correlations which was applied.

Borehole penetration and expansion devices for ice testing

1996 ◽  
Vol 23 (1) ◽  
pp. 157-164 ◽  
Author(s):  
Branko Ladanyi
Keyword(s):  
Special Kind ◽  
Strength Properties ◽  
Theoretical Interpretation ◽  
In Situ Testing ◽  
Cone Penetration ◽  
Creep Properties ◽  
Pilot Hole ◽  
Expansion Test ◽  
Sharp Cone

The paper presents two methods for in situ testing of strength and creep properties of ice, together with their theoretical interpretation and typical results. The two methods which are relatively new in this area of application, are the stress-controlled cone penetration test (CPT), and the sharp cone test (SCT). The CPT has been shown in the last few years to be an excellent tool for both ice quality profiling and ice creep and strength properties determination. The test can be used for penetrating vertically through an ice sheet, or laterally into an ice wall in a trench. The SCT is a special kind of borehole-expansion test. The method consists in pushing a smooth, low-angle, conical indentor into a predrilled conical portion of a borehole, which ends with a smaller diameter pilot hole. The creep properties of ice are then deduced from the relationship between the applied load, time, and cone penetration, which is directly related to the hole expansion. Key words: ice, creep, strength, in situ testing, cone penetration, borehole expansion, sharp cone.

Advanced Cone Penetrometer Development for In-Situ Testing at Gullfaks C

1987 ◽  
Author(s):  
J.M. Bayne ◽  
T.I. Tjelta
Keyword(s):  
Cone Penetrometer ◽  
In Situ Testing

Piezo-friction-cone penetrometer testing in soft clays

1987 ◽  
Vol 24 (4) ◽  
pp. 645-652 ◽  
Author(s):  
J.-M. Konrad
Keyword(s):  
Pore Pressure ◽  
Water Pressure ◽  
Testing Procedure ◽  
Soil Conditions ◽  
Cone Penetrometer ◽  
In Situ Testing ◽  
Soft Clays ◽  
Tip Resistance ◽  
Full Design

A comprehensive in situ testing program using a 50-kN electric piezo-friction-cone penetrometer was carried out at three different sites in soft marine clays. In these soils, the measured penetration resistance and friction are less than 4% of the full design capacity of the load cells. Although the strain gauges are temperature compensated, the importance of temperature effects in these soil conditions is demonstrated. The paper outlines a testing procedure to minimize the errors associated with zero shift in cone testing and to obtain meaningful data in weak soils with 50-kN penetrometers.Pore-water pressure measurements along the shaft are essential to evaluate the in situ test results in soft soils. Pore pressure distribution along the shaft is dependent on soil type, and measurements should be made at both ends of the friction sleeve for complete soil characterization.Friction along the shaft is not uniform and is negligible over an initial length of about 2 cone diameters in soft clays. Key words: soft clays, pore pressure, friction, tip resistance, in situ testing.

scholarly journals In situ strength characterisation of peat and organic soil using full-flow penetrometers

2011 ◽  
Vol 48 (7) ◽  
pp. 1085-1099 ◽  
Author(s):  
N. Boylan ◽  
M. Long ◽  
F.A.J.M. Mathijssen
Keyword(s):  
Organic Soil ◽  
Cone Penetrometer ◽  
Uniform Measure ◽  
In Situ Testing ◽  
Strength Parameters ◽  
Resistance Factors ◽  
Fibrous Peat ◽  
Penetration Tests ◽  
Range Of Values

Full-flow penetrometers have been shown to overcome problems experienced with the cone penetrometer when measuring resistance in very soft peat and organic soil, and give a much more uniform measure of resistance than the cone in fibrous peat. However, at present there is no guidance on the interpretation of strength parameters in these soils using the T-bar and ball. This paper examines the results of tests using these devices at two research sites in the Netherlands in conjunction with high-quality Sherbrooke sampling for laboratory testing. In fibrous peat, the T-bar and ball provided a more uniform measure of resistance with a lower degree of scatter than the cone. The in situ testing results have been compared with the laboratory tests to assess the range of resistance factors relating penetration resistance to the undrained shear strength (su) and have been shown to occupy a lower range of values than the cone penetrometer. However, penetration tests in these soils are likely to be influenced by partial drainage effects and this should be considered during testing and the subsequent interpretation of results. Recommendations are made for the use of full-flow penetrometers to obtain strength parameters in these soils.

Determination of creep properties of frozen soils by means of the borehole stress relaxation test

1993 ◽  
Vol 30 (1) ◽  
pp. 170-186 ◽  
Author(s):  
B. Ladanyi ◽  
M. Melouki
Keyword(s):  
Stress Relaxation ◽  
Strength Properties ◽  
Frozen Soil ◽  
Relaxation Test ◽  
Test Results ◽  
Stress Relaxation Test ◽  
Frozen Soils ◽  
Frozen Sand

The objective of this investigation was to evaluate the potential use of the borehole stress relaxation test to determine the creep and strength properties of frozen soils in situ. The paper presents the results of a series of laboratory pressuremeter relaxation tests performed in frozen sand and compares three possible interpretation methods for deducing from the test results the creep and strength parameters of frozen soils. Key words : borehole relaxation, pressuremeter, in situ testing, creep and strength properties, frozen soil.

Comparison of In-Situ Vane, Cone Penetrometer, and Laboratory Test Results for Gulf of Mexico Deepwater Clays

2009 ◽  
pp. 293-293-13 ◽  
Author(s):  
GW Johnson ◽  
TK Hamilton ◽  
RJ Ebelhar ◽  
JL Mueller ◽  
JH Pelletier
Keyword(s):  
Gulf Of Mexico ◽  
Laboratory Test ◽  
Cone Penetrometer ◽  
Test Results ◽  
Laboratory Test Results
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