Description

In-situ Test Data

Three field tests are supported in NovoLiq for liquefaction analysis: SPT, BDT and Vs. For more information on theory of each method please read this article. Each fields requires additional settings for applicable corrections on raw data. You can enter the field test data manually, import from Text files or import from gINT database files. 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

Press the Corrections button to access the page to edit the correction methods for in-situ test data. If SPT is selected as field test method, the following corrections will be applied on SPT numbers (N) to obtain N₆₀ and N1₍₆₀₎:

• Energy level: this will adjust the SPT equipment energy to standard 60% energy. This correction factor is named Ce.

• Borehole diameter: size of the borehole affects the SPT blow counts. This correction factor is named Cb.

• Sampling method: some SPT samplers have a liner. This will affect the SPT blow counts and its correction factor is called Cs.

• Rod length: this correction factor is called Cr and 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: this corrections is usually called "depth correction factor" or Cn and depends on overburden stress due to soil, at the test depth.

Please choose your favorite method for each correction factor. The following formula is used to calculate the correction factors at each depth:

C=Ce.Cb.Cs.Cr   N₆₀=C.N   N1₍₆₀₎=Cn.N₆₀

All the above-mentioned factors as well as N₆₀ and N1₍₆₀₎ are plotted versus depth and presented on screen.

Plot Data

Click on this hyperlink to see the test results plot versus depth.

Subsurface Layers

The table at the bottom of the page is for Soil Layers data. Data can be entered manually 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 apply any specific calculation method based on 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, you should remove this layer from liquefaction assessment by de-selecting the last column of the table ("Participates in liquefaction?").

Unit Weight : is 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 analysis.

Participates In 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).

Schematic Soil Profile

Is updated based on data entered in soil layers table (read more).

Analysis

Please enter information about the subject site, design earthquake and liquefaction analysis methods:

Peak Ground Acceleration (PGA) : is the PGA of the subject site.

Cyclic Resistance Ratio (CRR1) method: NovoLiq supports 10 methods of 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.

For calculating settlement and lateral spreading of the site during and after the liquefaction, following information are required:

Distance From Fault : is the distance for the subject site from the fault causing the design earthquake.

Ground Slope : site slope condition is one of the most important parameters in 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)

Misc.

Loading

This feature will consider the effect of structural load on mitigation of liquefaction potential (more information).

Ground Improvement

NovoLiq assumes that when ground improvement is carried out in a site, liquefaction will not be likely to occur in that specific depth range. If this is applicable to your site, enter depth range for ground improvement. All settlement and lateral displacement will be ignored in a ground improvement area and liquefaction will not be analyzed 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.