You must first select the type of in-situ data that you will use for the calculation of Cyclic Resistance Ratio (CSR). The data types that LiqIT currently supports are Standard penetration Test (SPT), Cone penetration Test (CPT) and shear waves velocity (Vs).
Insitu data type selection
According to the selection made the software will provide you with a worksheet area where all necessary input data are entered.
Data can be entered and manipulated in the worksheet area inside the In situ test data section. By default, LiqIT offers one worksheet named "Data 1" but you can insert (or delete) worksheet tabs by right clicking inside the worksheet name area.
Worksheet name area
A pop up menu will appear offering commands to add, rename and delete the current worksheet tab (delete command only works when at least two tabs are present).
Pop up menu for manipulating tabs
Each worksheet supports the most common window functions such as region selection, copy and paste data from or to other applications. In this way you may input your data with the following methods :
| 1. | Entering the data by keyboard. |
| 2. | Copy data from another application (e.g. Microsoft© Excel©) and paste them into the worksheet. |
| 3. | Reading a data file as described here. |
If you wish to preview your data you can click on the Preview data button.
Follows the description, in brief, of all the elements displayed, depending on the selected type of the in situ data.
Note The data entered to a worksheet cell apply to the test point of the specific row down to all other test points until another value is found in the same column. |
1. SPT input data
SPT worksheet
where:
| • | Depth: The depth at which the field test was performed |
| • | Nspt: The field SPT blow count (for a penetration depth of 30 cm or 1 ft). |
| • | Fines: The Fines Content in percent of the soil where the test was performed. If no value is entered then the software assumes a Fines Content equal to the value entered to the previous cell or, if no value is entered in previous cells, 0.00%. |
| • | Gamma: The bulk unit weight of the soil at the depth of the test . If no value is entered then the software assumes is equal to the value entered to the previous cell or, if no value is entered in previous cells, 19 kN/m³ (or 120 pcf). |
| • | Influence thickness: This is the thickness of the layer that corresponds to the specific SPT. The center of the influence thickness lies at the depth of the test point. This value will be used for the calculation of the expected post-liquefaction settlements. When importing data from a text file the software automatically calculates this value. If for any reason you need to automatically recalculate the influence thickness you can right click anywhere inside the worksheet and from the pop-up menu click on the Calc influence depth command. |
Pop-up menu
2. CPT input data
CPT worksheet
where:
| • | Depth: The depth at which the test was performed. |
| • | qc: The measured cone resistance. Please notice that when data from a CPTU (piezocone test) test are used the qc column must contain the corrected qt value. |
| • | fs: The measured sleeve resistance. |
| • | Gamma: The bulk unit weight of the soil at the depth of the test. If no value is entered then the software assumes unit weight is equal to the value entered to the previous cell or, if no value is entered in previous cells, 19 kN/m³ (or 120 pcf). |
| • | Fines: The Fines Content (in percent) of the soil where the test was performed. If no value is entered then the software assumes Fines Content is equal to the value entered to the previous cell or, if no value is entered in previous cells, 0.00%. You can estimate the fines content by applying the updated Robertson & Wride method by clicking on the Auto calc. fines button. The estimation is based on the soil behaviour type index IC, which is calculated from the qC and fS values. |
You may access a quick preview of the soil classification based on the tip resistance and sleeve friction values by clicking on the Soil Classification button.
Soil classification preview dialog
LiqIT offers two additional data modification features:
Note When working with CPT data, qc and fs values must be in the same units. You can specify which unit you are using by clicking on the appropriate selection in the qc & fs units ratio group. |
3. Vs input data
Vs worksheet
where:
| • | Depth: The depth at which the test was performed. |
| • | Vs: The measured shear waves velocity. |
| • | Fines: The Fines Content (in percent) of the soil where the test was performed. If no value is entered then the software assumes Fines Content is equal to the value entered to the previous cell or, if no value is entered in previous cells, 0.00%. |
| • | Gamma: The bulk unit weight of the soil at the depth of the test. If no value is entered then the software assumes unit weight is equal to the value entered to the previous cell or, if no value is entered in previous cells, 19 kN/m³ (or 120 pcf). You can estimate gamma value for every row, by clicking on the Auto calc. gamma button. |
| • | Fines: The Fines Content (in percent) of the soil where the test was performed. If no value is entered then the software assumes a Fines Content equal to a previous value if entered or 0.00% if no value is specified in all cells above. |
| • | Influence thickness: This is the thickness of the layer that corresponds to the specific Vs. The center of the influence thickness lies at the depth of the test point. This value will be used for the calculation of the expected post-liquefaction settlements. When importing data from a text file the software automatically calculates this value. If for any reason you need to automatically recalculate the influence thickness you can right click anywhere inside the grid and from the pop-up menu click on the Calc influence depth command. |
Pop-up menu
Note The estimation of unit weight value is valid only for cases where Vs measurements are contacted using a Seismic CPTU. |