**1.3. Theoretical Points of the Tunnel Template**

The application allows one to work with 3 kinds of cross-sections:

**Simple template:** A circular template defined from a radius.

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**Composite template:** Defined from a radius and sidewalls.

**Complex template:** Defined by a succession of curved and straight sections.

Of these, only the first two can be defined in the field data recorder itself. Complex cross-sections have to be created with the TcpTunnel CAD program. All cross-sections created in this module will be treated by the application as if they were complex, even if they are simple or composite cross-sections.

Said cross-sections can be included or not in the road surface or inverted arch zones. They will be considered as **Open** if they do not include them and **Closed** otherwise. The kind of cross-section one wishes to create has to be indicated in the field data recorder, while in CAD it is done automatically depending on whether the polyline created is open or closed.

The cross-section center and three distances marking where the alignment is marked on the ground plan, the vertical alignment and the superelevations will be requested in all cases. One must additionally specify how the cross-section varies as a function of the superelevations (see **Edit** section).

The vertical alignment and superelevation application point should be within the tunnel cross-section.

All the data referring to cross sections requested and shown in the application are understood to be in the forward direction of stations on the project’s alignment.

The survey and set out profiles, set out front and position options allow one to divide the section into specific theoretical points starting off from the keystone up to the values indicated to the left and the right of the keystone. Exclusion zones can be defined.

There are three different ways.

**Angle Increment:**

**Z (Height) Increment**:

**Length Increment**:

The screen below shows the data that has to be entered to divide the cross-section.

**Method**: Shows the three methods indicated above: **Angle (degrees), Height (meters)** and **Length (meters).** In the case of angles, gons or decimal degrees will be displayed, depending on the option selected in **Settings >** **Units of Measurement**.

**Interval**: A value that is always positive by which it increases or decrease starting off from the keystone to calculate theoretical points. For instance:

**Angle**: 20 degrees. Points calculated are: 0º (keystone), -20, -40, …, 20, 40, …

**Height**: 1 meter. The keystone is calculated as are the points at 1, 2, 3, etc. meters below it to the left and to the right.

**Length**: 2 meters. The keystone is calculated as are the points at 2, 4, 6, etc. meters of development to the left and to the right.

This option may be activated or deactivated. This allows one to only set out the keystone, which is always calculated, or unique points.

**Include Keystone**: Allows one to activate or deactivate the keystone point.

**Unique Points**: If this option is enabled, the cross-section’s unique points are added.

**Include Road Surface**: The road surface cross-section is made up of two segments that have the vertical alignment and superelevation application point as the initial point and the intersection with the left-hand (left-hand segment) and right-hand side (right-hand segment) of the tunnel cross-section as the final point. If there is a superelevations file in the project, these segments will be superelevated as per the superelevation of the corresponding station observed or indicated.

If this option is enabled, the cross-section limits will be marked by the final points of the segments mentioned above.

Shows template graphic containing the theoretical points calculated.

The blue points indicate the cross-section’s unique points, and the red points indicate the points calculated from the keystone on the basis of the increment indicated.

Regardless of the type of choice, **Interval**, **Unique Points** or both, one can exclude points from among all those calculated by any of the three methods. There are two ways of doing this, which can be used together:

1.- Establish the values of the **Initial Value** and **Final Value** boxes, so that only the points within the specified interval will be valid**.** The criteria for defining this interval are:

- Both values can be positive or negative.

- The initial value must always be smaller than the final value.

- The negative values indicate the left-hand side of the keystone and the positive values indicate its right-hand side.

- The range is created clockwise.

The > buttons alongside the **Initial** and **Final** boxes allow one to set a value by a reading.

Examples:

Angle: **Initial Value –100.0000 Final Value 125.0000**

Points included between 100 degrees to the left of the keystone and 125 to its right.

**Initial Value –100.0000 Final Value -20.0000**

Points included between 100 degrees to the left of the keystone.

Height: **Initial Value -10.0000 Final Value 5.0000**

Points included between 10 meters below the keystone on the left-hand side and 5 meters below the keystone on the right-hand side.

**Initial Value 4.0000 Final Value 12.0000**

Points included between 4 and 12 meters below the keystone on the right-hand side.

Length: **Initial Value -10,000 Final Value 12.5000**

Points included between a length of 10 meters along the left-hand side of the keystone and 12.5 meters on the right-hand side.

** Initial Value -9.0000 Final Value -5.0000**

Points included between a length of 9 and 5 meters along the left-hand side of the keystone.

2.- Establish exclusion zones, discarding the points included between the established intervals. The criteria for creating these zones are the same as in the previous section, with the difference that one can only establish angle values.

The buttons alongside the **Initial Angle** and **Final Angle** boxes allow one to set a value by measuring.