Loading test of drilled shafts in rock

2004 ◽  
pp. 379-410
Keyword(s):  
Drilled Shafts ◽  
Loading Test

scholarly journals Field Tests on Bearing Characteristics of Large-Diameter Combined Tip-and-Side Post Grouted Drilled Shafts

2021 ◽  
Vol 11 (24) ◽  
pp. 11883
Author(s):  
Zhitong Zhang ◽  
Weiming Gong ◽  
Guoliang Dai ◽  
Xiaolin Cao ◽  
Yu Zhu ◽  
...  
Keyword(s):  
Large Diameter ◽  
Standard Penetration Test ◽  
Drilled Shafts ◽  
Load Test ◽  
Cohesionless Soil ◽  
Cement Slurry ◽  
Test Procedures ◽  
Loading Test ◽  
Static Test ◽  
Tip Resistance

This paper presents a field study on the axial behavior of four large-diameter drilled shafts embedded in coarse sand. The grouting and loading test procedures were reported. The bearing capacity of shafts (TS1 and TS2) and grouted drilled shafts (TS3 and TS4) were herein determined by the bi-directional static test and top-down load test, respectively. The enhancement mechanism of bearing characteristics of the grouted shafts was discussed in detail. The test results indicate that the bearing characteristics and load transfer mechanisms of the test shafts were significantly affected by the quantity of pressurized cement slurry and the mechanical properties of the soil surrounding the shafts. Furthermore, the tip resistance of shaft can be mobilized more rapidly and fully after grouting, the side and tip resistance are mobilized in a more synchronized and coordinated manner due to the pre-mobilization of the grouted cement. Additionally, the standard penetration test (SPT) prediction model was introduced to calculate and predict the SPT blow counts of soil after grouting. The results show that the post grouting has a more obvious improvement on the strength of cohesionless soil.

STEROID METABOLISM IN THE PERFUSED HUMAN PLACENTA

1978 ◽  
Vol 87 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Alfred S. Wolf ◽  
Klaus A. Musch ◽  
Werner Speidel ◽  
Jürgen R. Strecker ◽  
Christian Lauritzen
Keyword(s):  
Venous Blood ◽  
Placental Lactogen ◽  
Dehydroepiandrosterone Sulphate ◽  
Metabolic Capacity ◽  
Loading Test ◽  
Lower Range ◽  
Group I ◽  
High Concentrations ◽  
Steroid Precursor

ABSTRACT A new model for the perfusion of human term-placentas has been developed for studies on the placental biogenesis of C-18 and C-19 steroids. For viability criteria, the glucose- and oxygen-consumption, regional perfusion control by dye-infusions or scanning after injection of 99Tc-labelled macroparticles, and the histological qualification were chosen. The recycled perfusate was investigated for the steroids oestrone (Oe1), oestradiol-17β (Oe2), oestriol (Oe3), 4-androstene-3,17-dione (A), testosterone (T), and human placental lactogen (HPL) by radioimmunoassay in controls and perfusions with the foetal steroid precursor dehydroepiandrosterone sulphate (DHA-S). In control perfusions, steroid hormones were found in constant ratios (Oe1:Oe2:Oe3:T:A = 30:1.5:100:0.35:1). Following the administration of 10 mg DHA-S for testing the metabolic capacity of the organ, high concentrations of Oe1 (90–720 ng/ml = 250–3970 % as compared to 100% pre-injection values) were found, shortly preceded by a rapid increase of A (66–1000 ng/ml = 100–16 000 %). A typical surge of T (5.3–147 ng/ml = 265–4640 %) preceded the normally slower increment of Oe2 (22–220 ng/ml = 1570–4330 %). The concentrations of Oe3 and HPL remained nearly unchanged. From different steroid patterns after DHA-S-load, two distinct responses of term-placentas could be differentiated: Group I (n=12) showed high concentrations of Oe1 (3200 ± 940 %), a small increase of T (1020 ± 500%), as well as low and delayed values of Oe2 (1660 ± 450%). In Group II (n = 5), values were high for T (3160 ± 1020%) and Oe2 (3300 ± 1110%), whereas Oe1 was found in a lower range (508 ± 302%). In contrast to in vivo findings in maternal venous blood after DHS-S injection to the mother, oestrone was found in perfusions as the main oestrogen fraction from DHA-S. Thus, the analysis of such metabolic differences might be of help in the interpretation of complex results from the DHA-S-loading test.

STEROIDSTOFFWECHSEL BEI BRUSTKREBS. III.

1959 ◽  
Vol XXXII (I) ◽  
pp. 23-32 ◽  
Author(s):  
Kurt Schubert ◽  
Hans Schröder
Keyword(s):  
Advanced Cancer ◽  
Liver Damage ◽  
Adsorption Chromatography ◽  
Hepatic Insufficiency ◽  
Loading Test ◽  
Patients With Cancer ◽  
Urinary Steroids ◽  
Normal Women

ABSTRACT A testosterone test using two different dosages was carried out simultaneously in 7 women suffering from metastasizing carcinoma of the mamma and in 3 normal women. In each case the urinary steroids were estimated before the beginning of the test and after administration of 50 mg and 100 mg of testosterone respectively; the interval between the single estimations being one week. The use of fractionated hydrolysis enabled a mild fission of the conjugates and the classification of the products into free steroids, glucuronosides, sulfates and unknown conjugates. The 17-ketosteroids and the testosterone were estimated by means of Girard's separation and adsorption chromatography. During the loading test with testosterone different behaviours became evident, which had not been realized before. The behaviour of the 17-ketosteroids rendered possible the differentiation of normal women from patients with cancer of the breast yet without hepatic insufficiency, and furthermore of these latter ones from those with a liver damage in addition to the cancer of the breast. The glucuronosides of the 17-ketosteroids are only depressed, when there exists a pronounced damage of the liver; the loading test making possible an extension of the range of recognizable damages. Furthermore, the behaviour of dehydroepiandrosterone (II/III), of androsterone (IV), and of aetiocholanolone (V) lends itself to this differentiation. In advanced cancer of the breast the values of II/III are invariably low, whilst IV and V often increase temporarily. The relation of IV to V may be altered in a different way. The excretion of not transformed testosterone is less in patients than in normal women and especially low in patients with liver damage.

Restoring Initially Cracked Reinforced Concrete Beams utilizing Carbon Fiber Reinforced Polymer Strips

2019 ◽  
Vol 7 (1) ◽  
pp. 30-34
Author(s):  
A. Ajwad ◽  
U. Ilyas ◽  
N. Khadim ◽  
Abdullah ◽  
M.U. Rashid ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Loading Test ◽  
Control Beam ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced polymer (CFRP) strips are widely used all over the globe as a repair and strengthening material for concrete elements. This paper looks at comparison of numerous methods to rehabilitate concrete beams with the use of CFRP sheet strips. This research work consists of 4 under-reinforced, properly cured RCC beams under two point loading test. One beam was loaded till failure, which was considered the control beam for comparison. Other 3 beams were load till the appearance of initial crack, which normally occurred at third-quarters of failure load and then repaired with different ratios and design of CFRP sheet strips. Afterwards, the repaired beams were loaded again till failure and the results were compared with control beam. Deflections and ultimate load were noted for all concrete beams. It was found out the use of CFRP sheet strips did increase the maximum load bearing capacity of cracked beams, although their behavior was more brittle as compared with control beam.

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