Ocr and pop parameters in plaxisbased numerical analysis of loaded over consolidated soils. Since then, the ocr communitys brightest minds have been working to improve the softwares stability, and a dozen years later, tesseract can. The rate of secondary consolidation is not dependent on the flow of water or on clay layer thickness, and is relatively constant for normal engineering stress increases. Ocr and pop parameters in plaxisbased numerical analysis. Several correlations have been developed by geoscientists in order to estimate one soil parameter based on a series of other known soil parameters. Pdf overconsolidation ratio determination of cohesive soil. Here, the term ocr is over consolidation ratio, is preconsolidation stress and is effective overburden stress. I have seen quite a bit of samples with overconsolidation ratio ocr less than 1 from oedometer tests. In this paper, relevant parameters of the hs model in shenzhen bay in china were studied through onedimensional consolidation tests and triaxial shear tests.
Selection of consolidation parameters such as compression index c c, recompression index c r or coefficient of volume change m v is on the basis of ocr for computing consolidation settlement. The ocr is defined as the ratio of the maximum past effective consolidation stress and the present effective overburden stress. This test is widely used to obtain the bearing capacity of soil for shallow and deep pile foundations. Prior to reclamation, a site investigation program including. It lets you scan the hard documents with the help of scanner and lets you extract text from images and pdfs. In soils mechanics, the over consolidation ratio ocr is the relation between the preconsolidation pressure and the current effective stress of the soil.
The overconsolidation ratio ocr of a soil is important in that the ratio affects the. Also shown on figure 2 are the data presented by ladd et al. Secondary consolidation occurs slowly with a continually decreasing rate. Translate ocr in german online and download now our free translator to use any time at no charge. The secondary consolidation portion of the consolidation curve is approximately linear. Some have told me that it is a testing artefact due to disturbance of the soil, they say technically ocr cannot be less than 1. An efficient and comprehensive software solution designed specifically for analyzing cone penetration tests, as well as liquefaction and settlement analyses. Software systems with a wide range of soil models such as plaxis. The software features full reduction of time consolidation data, including both square root and log of time methods.
You could spend hours retyping and then correcting misprints. Methods for evaluating overconsolidation ratio from piezocone. Well then lets not beat around the bush, and get to the 8 best ocr software you should use in 2020. These software can either acquire the source from scanning devices, or you can input your own images or pdf files to be converted into editable text. In forming the initial stress state of over consolidated soils with the preoverburden pressure pop, there occurs the more reliable description of the soil deformation process than with the over consolidation ratio ocr. Soil mechanics consolidation over consolidated clays now this is where it gets interesting. The behaviour of soft clay can be classified according to the over consolidation ratio ocr of the soil. The expression for computing the ocr is as given below.
There are several existing methods for evaluating the ocr from the results of. A soil that is currently experiencing its highest stress. Freeocr is a versatile free ocr optical character recognition program for windows. Find the overconsolidation ratio ocr for test number 8 using the equation 1 denote preconsolidation stress as, and vertical effective overburden stress as. Ocr is a function for undrain shear strength ratio su p. Optical character recognition, conversion of images of text into characters. Denote preconsolidation stress as, and vertical effective overburden. If ocr1 the soil is normally consolidated nc, if ocr1 the soil is over consolidated oc. Ocr values based on laboratory, cptu and sbp tests. The hardening soil hs model is the most commonly used constitutive models of soft soil of foundation pits of plaxis software in numerical analysis, and its parameters are prerequisite for accurate calculation. The linearelastic perfectlyplastic mohrcoulomb model involves five input parameters, i. Calculations of consolidation settlements the values of cr obtained as recommended in the previous section are used to calculate the apparent consolidation settlement s from equation 4.
This software is used for correlation estimation of soil properties. Overconsolidation ratio an overview sciencedirect topics. The engineering properties of the clay samples are obtained and the relation between deviator stress, pore water pressure and principal effective stress. It is obtained by dividing the preconsolidation pressure by the present effective stress value applied on the soil. Determine the overconsolidation ratio ocr for the fiv. Substitute the values of 200 kpa for, and 160 kpa for in equation 1 to get. We serve businesses in industries as varied as healthcare, automotive, retail, financial, and hospitality, as well as engineering firms and government entities. If ocra1, the soil is considered to be normally consolidated, when ocr 1 it is overconsolidated. Geotechnical correlations software novo tech software.
The standard penetration test spt is the most popular and economical test for evaluation of subsurface information, both on land and offshore. Estimation of the residual strength of the soil on the landslide sliding surface is essential for analyzing reactivated landslides. The over consolidation ratio or ocr is defined as the highest stress experienced divided by the current stress. Ocr acronym or abbreviation in soil all acronyms dictionary. Parameter analysis on hardening soil model of soft soil.
The overconsolidation ratio ocr is defined as the highest stress experienced divided by the current stress. Transvaginal oocyte retrieval, a technique used in in vitro fertilization over consolidation ratio, a consolidation measurement in geotechnical engineering official cash rate, the interest rate. Ocm remains same throughout the data but ocr varies as a function of depth. When checked the software will try to estimate over consolidation ratio number, k ocr for every cpt point. Quick settlement computation of shallow foundations using. Suppose you wanted to digitize a magazine article or a printed contract. If the soil is overconsolidated, adjustment of the coefficient of earth pressure ko is required specifying the value of the overconsolidation ratio ocr and preoverburden pressure pop.
Methods for estimating the overconsolidation ratio ocr of soil deposits from. You can extract all the pages of multipage pdf or extract text from current page. Stress history overconsolidation ratio ocr 38 insitu stress ratio ko 39 friction angle 40 relative density dr 42 stiffness and modulus 44 modulus from shear wave velocity 45 estimating shear wave velocity from cpt 46 identification of unusual soils using the scpt 47 hydraulic conductivity k 48 consolidation characteristics 51. The mohrcoulomb model represents a firstorder approximation of soil or rock behaviour. Guide to cone penetration testing novo tech software. These days, it is quite common to scan the documents to view and share via electronic means conveniently. Overconsolidation ratio of a seabed clay from insitu tests issmge. Coefficient of primary and secondary consolidation, void ratios, compression and recompression indices, preconsolidation and swell pressures, t 0, t 50, t 90 and t 100, and swellcollapse percentages are calculated and reported. Pdf ocr and pop parameters in plaxisbased numerical. The formation of clay soil defines the ocr values and it can be described as the ratio of. Pdf in order to evaluate overconsolidation ratio ocr of soil, the necessity to restore them as much as possible to in situ conditions appears. Over consolidation ratio, a consolidation measurement in geotechnical. For example, if you need to estimate consolidation compression index cc, instead of searching through several reference books, just run novoformula and find the recommended cc values based on several equations available in its database more than 140 equations. Software systems with a wide range of soil models such as plaxis, abaqus, zsoil.
In order to evaluate overconsolidation ratio ocr of soil, the necessity to restore them as much as possible. Ocr is a function for undrain shear strength ratio s u p. Profiling and analysis of the overconsolidation ratio and. Novospt is a powerful, userfriendly geotechnical software for correlating soil properties from spt blow counts. Or you could convert all the required materials into digital format in several minutes using a scanner or a digital camera and optical character recognition software. Relationship between k0 and overconsolidation ratio.
The stress history as indicated by the profile of overconsolidation ratio ocr of a soil deposit is one of the most dominant factors that influence the engineering behaviour of the soil. We have gone through more than 70 published papers and geotechnical reference books and collected over 300 spt correlations with various soil properties. The term is commonly used in such software as omnipage pro 8005357226 to indicate options of translating scanned words and numbers into computer text files that can be read by word processing and spreadsheet software. It cannot be used to compute pre consolidation stress at other depths in a stratum. This study investigated the influence of overconsolidation ratio ocr and shear rate on the residual strength of smtype silty sand landslide soils in the three gorge reservoir using ring shear tests under drained conditions. The ratio of pre consolidation stress to the initial vertical effective stress is known as over consolidation ratio. In truth, several prior theoretical approaches have addressed the k0ocr. Soil consolidation refers to the mechanical process by which soil changes volume gradually in. Spt correlations software novospt novo tech software.
Under consolidated soil over consolidation margin ocr. These findings are valid for odometer conditions and for. Optical character recognition software and hardware used to interpret scanned symbols into characters of text or numbers recognized as something other than mere graphics images. It is pretty intuitive that the stress applied to the soil weight of the footing and the load the foot distributes depends on the rates and distance of settlement. Find the overconsolidation ratio ocr for test number 8 using the equation 1. If unchecked then a custom constant value is used default value to 0. What is the overconsolidation ratio ocr at the mid point of the clay layer. This study investigated the influence of overconsolidation ratio ocr and shear rate on the residual strength of smtype silty sand landslide soils in the three gorge reservoir using ring. Soil deformation is higher in normally consolidated soil than it is over consolidated soil. Ocr optical character recognition explained learning.
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