Formwork system

[0001] The present invention relates to a formwork system, especially for tunnel construction. The formwork system includes at least one support arrangement for supporting a formwork having a plurality of formwork elements. The formwork system includes at least one controller for the support of the formwork elements and the concrete supply for the space to be filled with concrete. An example of a generic prior art formwork system is disclosed in U.S. Pat. No. 2,626,509.

[0002] It is an object of the invention to improve the current generic formwork system so that allowances can be made for individual circumstances in the construction of a concrete wall, in particular of a concrete crown.

[0003] According to the invention, at least two pressure sensors are disposed vertically at different positions on the formwork element and/or on the support arrangement and connected to the controller of the formwork system. The pressure sensors are designed to measure the pressure acting upon the formwork elements due to the concrete poured into the formwork at a minimum of two different heights of the formwork element. The controller is designed to control the concrete supply units individually dependent on the signal from the pressure sensors. In this way it is possible to measure the concrete pressure acting at different points on the formwork element (or preferably plurality of formwork elements) and the controller can compare the pressure values measured by the pressure sensors with set values and control the concrete supply so that the concrete pressure at the different points of the formwork elements conforms to the set values. In this way a concrete wall, in particular a concrete crown, can be produced with specified homogeneous material properties throughout the entire wall or crown area.

[0004] In a preferred embodiment of the invention, the support arrangement has at least one hydraulic support beam for supporting the formwork element and the controller is designed to control the force of the support beam dependent on the pressure measured in the pressure sensors. The pressure can therefore be regulated not only through the individual concrete supply unit, but also through the support pressure by means of the support beams. Moreover, the pressure sensors do not have to be provided in the formwork itself, but can be disposed on the force absorption elements of the formwork elements, for example at the points at which the support structure statically supports the formwork element. In particular, if the entire formwork includes a plurality of formwork elements, which is normal in tunnel construction, one is able to exactly measure the pressure acting on the single formwork elements at the support points of the formwork elements and to control or regulate the concrete supply units and/or the support force of the hydraulic support beams accordingly.

[0005] In a technically simplified embodiment, the pressure sensor is disposed at the connecting point between the support beam and the formwork element and/or the support arrangement. Such an arrangement is easy to implement, for example by means of force sensors that are known in the art.

[0006] Preferably, a plurality of pressure sensors is disposed two-dimensionally distributed over the formwork element. Preferably the pressure sensors are disposed evenly over the entire surface of the wall and therefore over the surface of the formwork elements, if multiple sensors are used. In this way it is possible to detect a very good pressure distribution of the concrete on the formwork and to adjust the pressure, if necessary.

[0007] Preferably, the formwork system contains at least one vibration device and the controller is designed to control the vibration device dependent on the pressure measured in the pressure sensors. In this way, it is possible to increase the concrete pressure by means of additional vibration in areas where the concrete pressure acting on the formwork is too low. The vibration device can be disposed, for example, in combination with the formwork elements. However, external vibrators can also be provided in combination with the concrete supply units, which affect the viscosity of the supplied concrete.

[0008] Preferably, a plurality of vibration devices is disposed at different positions on the formwork element and the controller is designed to control the vibration device individually dependent on the signals from the pressure sensors. In this way it is possible to achieve a specified pressure profile of the concrete on the formwork elements, producing desired homogeneous strength properties over the surface of the concrete wall. Preferably, the vibration devices are disposed evenly distributed over the formwork elements. In this way, it is possible to achieve an even compaction across the surface of the formwork.

[0009] In a preferred further embodiment of the invention, the controller is designed to control the concrete pump dependent on signals from the pressure sensors. Different concrete pumps can be provided for different concrete supply units, for example, and the pressure acting on the formwork element can be influenced through the pumping pressure of the concrete pump.

[0010] Preferably, the at least one concrete pump is connected by means of at least one distribution device to a plurality of concrete supply units. In this case, the controller is designed to control the distribution device dependent on the signals from the pressure sensors, in order to achieve a homogeneous, specified pressure profile and therefore desired material properties of the concrete wall produced.

[0011] Preferably, the controller has a display for displaying the formwork elements and the pressure values measured there. In this way an operator can see the pressure values that were recorded at different parts of the formwork elements and can immediately determine whether the concrete has been supplied in the specified manner to the space behind the formwork elements. This is extremely important when constructing a tunnel crown, for example, since it must be ensured that the concrete fills the space completely between a tunnel wall and the formwork elements at all points beyond the formwork elements and is therefore able to meet the required strength properties of the tunnel crown.

[0012] In a preferred embodiment of the formwork system, according to the invention, this formwork system has at least four formwork elements, which are supported against the support arrangement by at least four support beams. Such an arrangement is therefore appropriate for a tunnel crown, the four formwork elements more or less forming the upper semicircle of the tunnel crown. Preferably, the four formwork elements are arched and form a crown surface for a tunnel crown.

[0013] Since a tunnel formwork is generally very long, the formwork system according to the invention preferably has a plurality of consecutive, horizontally disposed support arrangements with their own formwork elements. The controller is then designed to individually control the pressure applied to the formwork elements of the single support arrangements dependent on the pressure values from the pressure sensors. In this way it is possible to produce a homogeneous tunnel formwork over an extended length in one process, in which very good homogeneity of the concrete wall is achieved over the surface.

[0014] In a method according to the invention, that uses the formwork system according to the invention, a concrete wall is erected in which the pressure acting on the formwork element is measured by means of pressure sensors at different points and the at least one concrete pump and/or the concrete supply unit is/are controlled dependent on the signals from the pressure sensors. In this way it is possible through individual control of the concrete supply unit and/or of the concrete pump(s) to ensure that an even pressure profile or a specified pressure profile is achieved over the surface of the formwork elements, which results in tunnel crowns with the required strength properties.

[0015] The signals from the pressure sensors can also be used to control vibration devices or distribution devices between the concrete supply units in order to fill the concrete supply unit to the individual locations between a tunnel wall and the formwork elements as evenly and homogeneously as possible.

[0016] In addition to the signals from the pressure sensors, the signals of other sensors, such as temperature sensors, optical sensors or chemical sensors, can also be used to control the support arrangement, the individual concrete supply units and the vibration devices.

[0017] With the invention, it is therefore possible to determine and analyze the properties of the concrete poured into the formwork and to use this information for control of the concrete supply units, the support arrangement and the vibration devices. For better operation the controller preferably has a display, which displays the formwork system two-dimensionally, as well as a concrete filling display for the different areas of the formwork elements. The measured forces are preferably analyzed by a software and displayed both digitally and visually. Preferably, the controller has an interface for controlling additional components, such as a vibration device, and also for transfer of the data to external data carriers or to an additional PC. On the basis of the measured signals from the pressure sensors, the compaction can be controlled automatically beyond the formwork elements.

[0018] The invention provides a countercheck for the static calculation of the formwork process. This substantially increases the safety of the formwork system and of the persons who operate the formwork system. The tunnel walls that are produced are better and more homogeneous, which optimizes the concrete pouring processes. With the invention, concrete walls and crowns are produced in conformity with standards. The controller outputs can also be used for safety systems, if excess voltages or excess pressures need to be determined at individual locations of the formwork elements. The invention contributes to the quality assurance of the structure.

[0019] An essential aspect of the invention is that, by means of selective control of the concrete pump and/or of the concrete supply unit and/or of the at least one vibration device, the concrete compaction processes can be controlled selectively and individually, in order to achieve desired material properties of the completed concrete wall and/or of the completed concrete crown.

[0020] It is apparent to those skilled in the art, that the single components of the invention can be provided singly or severally and that they can also be embodied as an integrated unit or distributed at a plurality of locations. The controller can comprise a plurality of computers, which is distributed over the length of the tunnel. A tunnel formwork system likewise normally comprises a plurality of formwork elements, e.g. four formwork elements distributed over the crown sector and three to six support arrangements in succession with four formwork elements, respectively, so that the overall system preferably comprises between ten and fifty formwork elements.

[0021] The following terms are used synonymously: vibration device—vibrator; pressure sensing device—pressure sensor; temperature sensing device—temperature sensor.

[0032] FIG. 1 shows a tunnel formwork system 10, according to the invention, that is located within an opened up tunnel crown 12. The tunnel formwork system 10 according to the invention is made up of a support arrangement 14 for supporting a formwork 15, which includes mutually pin-connected formwork elements 16-26, whose outer side is slightly arched and is oriented to the tunnel crown 12. Between the outer side of the formwork elements 16-26 and the tunnel crown or tunnel wall 12 an empty space 28 is formed, which is filled with concrete 13. The support arrangement 14 contains hydraulic support beams 30 to support the formwork elements 16-26 with a specified pressure against the poured concrete 13. The formwork system 10, according to the invention, is controlled by a central controller 32, which preferably has a monitor 34 for depicting the formwork system and the corresponding measured values. The formwork system 10 further includes a concrete pump 36 with a distribution device 38 and concrete pipes 40, which lead to the single concrete supply units 42, which are depicted in more detail in FIGS. 2 and 5. The central controller 32 is connected to pressure sensors 44, and also to temperature sensors or ultrasonic sensors 46, which measure both the pressure acting on the formwork elements 16-26 due to the poured concrete and the temperature of the concrete, in order to provide information to the central controller 32, both about the density and fill level of the concrete in the space between the outer side of the formwork elements 16-26 and the tunnel wall 12 and also about the chemical reaction during setting of the concrete, which chemical reaction is accompanied by heat generation or a change in the density. By measuring the temperature or the density it is therefore possible to determine with accuracy the progress of the setting reaction. For this purpose the controller is optionally connected to a concrete analysis device 48, which for example analyzes the setting behavior of a concrete sample and also possibly of its strength, in order to draw inferences about the strength of the concrete between the formwork elements 16-26 and the tunnel wall.

[0033] The controller 32 is of course connected to the concrete pump 36 and also to the distribution device 38. Further, the controller preferably has a USB interface 50, and a wireless interface 52, such as Wi-Fi® or Bluetooth®.

[0034] Due to the measurement of the temperature, density and pressure conditions depicted in FIG. 1 it is possible for the formwork system to control the single concrete supply units 42 and/or the hydraulic supports 30 so that the concrete flows and is compacted in a desired manner and also in accordance with the specified pressure conditions, in order to ensure the desired quality of the concrete formwork.

[0035] FIG. 3 likewise shows the formwork system 10 of FIG. 1, here depicting the connection of the central controller 32 to the vibrators 54. The central controller 32 can individually control the single vibrators 54 dependent on the sensor values, in order to achieve selective compacting of the concrete in different areas of the tunnel wall 12, therefore ensuring a concrete quality with the highest possible homogeneity over the entire tunnel wall 12.

[0036] FIG. 4 shows the connection of the central controller 32 with differential level sensors 56, which for example can be pressure sensors, optical sensors, thermal sensors, ultrasonic sensors or chemical sensors. These differential level sensors 56 are distributed evenly over the outer side of the formwork elements 16-26. In this way it is easily possible to measure a different fill height h1, h2 of the concrete 13 on both sides of the tunnel wall and, through individual control of the concrete supply units 42 and vibrators 54, to ensure that the fill level is even and regular on both sides.

[0037] FIG. 5 shows the connection of the central controller 32 to the single concrete supply units 42. Through control of the concrete pump 36 and of the distribution device 38 and other distribution elements not depicted, such as shut-off valves, it is possible to supply the concrete selectively to the single concrete supply units 42 in order to achieve a homogeneous concrete supply. Ideally the concrete is supplied via the relatively evenly distributed concrete supply units 42 in combination with corresponding actuation of the vibration devices 54 of FIG. 3.

[0038] FIG. 6 shows the connection of the central controller 32 to pressure sensors 58, which extend evenly over the upper section of the tunnel formwork, i.e. over the upper formwork elements 20-24, so that due to this arrangement of pressure sensors 58 it can be verified whether the concrete 13 between the tunnel wall 12 and the outer side of the formwork elements 16-26 is in fact completely filled, which finds expression in corresponding pressure values. These pressure sensors can also be embodied as hydraulic cylinders, which deliver controllable support pressure for the formwork elements. These pressure sensors 58 can therefore also be used for pressure control of the support pressure of the formwork elements 20 to 24.

[0039] Finally, FIG. 7 shows a top view of the formwork system according to the invention as shown in FIG. 1-6, however in an isolated view, i.e. not in operating position in a tunnel crown 12.

[0040] FIG. 8 shows a formwork system 60 for producing straight walls. The formwork system 60 comprises a support arrangement 62, a central controller 32 with a display 34, a concrete pump 36, possibly a distribution device, which is not depicted, optionally a concrete analysis device 48 and a plurality of flat formwork elements 72-78, which are disposed one above the other and side by side in order to form a wall of the desired size. The controller is connected by means of a first control line 80 to concrete supply units 82. By means of a second control line 84 the controller 32 is connected to a temperature sensor or ultrasonic sensor 86. By means of a third control line 88 and a fourth control line 90 the controller 32 is connected to pressure sensors 92. In this way the central controller 32 measures the pressure conditions and also the temperature conditions on the side of the formwork 71 facing the concrete 13, which side consists of the single formwork elements 72-78.

[0041] FIG. 9 shows the formwork system 60 of FIG. 8 in top view. It should be noted that identical or functionally equivalent elements are designated in the figures with identical reference marks.

[0042] The invention can deviate from the depicted embodiment, which therefore should not be understood as limiting the subject matter of the invention. The invention can be varied as desired within the scope of protection of the following claims.

• [0043] 10 tunnel formwork system
• [0044] 12 tunnel wall—tunnel crown
• [0045] 13 concrete layer
• [0046] 14 support arrangement
• [0047] 15 formwork
• [0048] 16-26 formwork elements
• [0049] 28 empty space
• [0050] 30 support cylinder/support beam
• [0051] 32 central controller
• [0052] 34 display
• [0053] 36 concrete pump
• [0054] 38 distribution device
• [0055] 40 concrete pipes
• [0056] 42 concrete supply units for supply to the formwork
• [0057] 44 pressure sensors
• [0058] 46 temperature sensor/ultrasonic sensors
• [0059] 48 concrete analysis device
• [0060] 50 USB or other interface
• [0061] 52 Wi-Fi or WLAN transmitter
• [0062] 54 vibrator
• [0063] 56 sensors
• [0064] 58 pressure sensors
• [0065] 60 formwork system for flat walls
• [0066] 71 flat formwork
• [0067] 80 first control line
• [0068] 82 concrete supply unit
• [0069] 84 second control line
• [0070] 86 temperature sensor/ultrasonic sensor
• [0071] 88 third control line
• [0072] 90 fourth control line
• [0073] 92 pressure sensor