Soil Stratigraphy
Use this table (located at the top of the page) for entering Soil Layers data. This data may be entered manually (line by line) or can be imported from text file.
Layer Thickness : represents thickness of the layer.
Soil Type : can be Clay, Silt, Sand or Gravel and is only for user's information. This means that NovoLiq does not take any specific action based on the soil type. For example if you select Clay as the soil type for a layer and you don't consider this layer to be liquefiable (see "Prone to Liquefaction" below), you should remove this layer from liquefaction assessment by un-selecting the last column of the table ("Prone to liquefaction?").
Unit Weight :represents the unit weight of the layer.
Fines Content (%): is the percentage of soil particles passing through sieve #200 (clay and silt).
D50 (mm) : is the particle diameter corresponding to 50 percent passing, in sieve analysis curve. D50 is only used for Japanese Bridge Code method.
Check for Liquefaction : if selected, liquefaction analysis will be carried out for this layer. For example if there is a clay layer in the subject site, which is not essentially prone to liquefaction, you can remove the checkbox for this layer; in this case a gap will appear on the output graphs corresponding to this layer (because NovoLIQ just skips the liquefaction assessment for this layer).
Field Test Data
Three type of field tests are supported in NovoLIQ for soil liquefaction analysis: SPT, BDT and Vs. For more information on theoretical background of each method please read this article. Each dataset obtained from a field test requires additional corrections. You can enter the test data manually, or import from Text files, or import from gINT database files. In any case, the test data will be entered in the table located at the left side of the page. The graph on the right-hand side of the page will be automatically updated based on the data in this table. It will also show the variation of field test results in depth of subsurface soil layers.
Corrections
The settings for corrections are displayed at the bottom-left portion of screen. If the test type is SPT or DCPT, the following corrections will be applied on SPT blows (N) in order to obtain N60 and N1(60):
- Energy level (Ce): this will adjust the SPT equipment energy to standard 60% energy.
- Borehole diameter (Cb): size of the borehole affects the SPT blow counts.
- Sampling method (Cs): specifies whether the sampler has a liner.
- Rod length (Cr): this correction factor depends on length of SPT rods which is approximately equal to the depth of the test. The following formula proposed by Dr. Cetin is used in NovoLiq:
- Overburden stress (Cn): this corrections is usually called "depth correction/normalization factor" and depends on overburden stress due to the weight of the soil above the testing depth.
Please choose your favorite method for each correction factor. The following equations are used to calculate the actual correction factor at each depth:
C=Ce.Cb.Cs.Cr N60=C.N N1(60)=Cn.N60
All the above-mentioned factors (including N60 and N1(60)) are plotted versus depth and presented on the screen.
Schematic Soil Profile
An schematic soil profile is presented on the "Start Analysis" page, based on data entered in soil layers table (read more).
Analysis Settings
On the left portion of the screen, you can choose various methods for liquefaction analysis. Particularly, you can enter site-specific seismic data by clicking on Site's Seismic Data button:
Maximum Earthquake Acceleration (amax) : is the maximum ground acceleration caused by the earthquake.
Earthquake Magnitude: is the magnitude of the earthquake and affects the MSF factor.
Cyclic Resistance Ratio (CRR1) method: NovoLIQ supports 10 methods for calculating CRR1 (for an earthquake magnitude of 7.5). User may select more than one method of analysis and NovoLiq will provide comparison of all selected methods in outputs. Please click on each method to toggle on/off. In order to estimate the settlement and lateral spreading of the site during and after the liquefaction, the following information are required:
Distance From Fault : is the distance (km) of the subject site from the fault causing the design earthquake.
Site Topography : site slope condition is one of the most important parameters in estimation of post-liquefaction lateral displacement. Zhang & Robertson (2004) recommend using S≥0.6% (for gently sloped ground) and 40≥L/H≥4 (for free face ground).
Other Analysis Settings
Surcharge Load: This feature will consider the effect of the structural load (stress below the footing) on mitigation of liquefaction potential (more information).
Ground Improvement: NovoLIQ assumes that when ground improvement (stone column or similar) is carried out at a site, soil liquefaction will not be likely to occur within that specific depth range. If this is applicable to your site, enter depth of ground improvement. All settlement and lateral displacement will be ignored within the ground improvement area and soil liquefaction will not be assessed in that depth range (a gap in the output tables and graphs).
Additional Settings: This will show the Analysis Methods tab from the Preferences page.
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