METHOD AND ARRANGEMENT FOR MONITORING A STRUCTURE FOUNDATION

Description

[0001] The invention relates to a method for monitoring a building foundation in a soil for a building, according to claim 1.

[0002] The invention further relates to an arrangement for monitoring a building foundation in a soil for a building according to claim 9.

[0003] To monitor building foundations, it is generally known to install various sensors in or on the foundation of a structure, which can be used to monitor the condition of the building foundation. Such sensors can measure deformations, cracks, settlements, or forces in the building foundation. It is also known to feed the measured data to a central location, which compares the measured values ​​with stored limit values ​​in order to detect excessive or impermissible changes to the building foundation at an early stage. This allows, for example, the possibility of implementing remedial measures on the building foundation or the structure itself at an early stage to prevent major damage.

[0004] Such a system for monitoring the structure of a bridge is described, for example, in US 8,990,027 B2 or the corresponding EP 2 391 776 B1.

[0005] The soil conditions in which the building foundation is to be constructed are of crucial importance for determining the load-bearing capacity of a building foundation. The building foundation must be designed based on the soil's load-bearing capacity. Determining the soil conditions as realistically as possible is particularly important for larger structures. For example, a building foundation on soft or sandy soils must be designed significantly differently than on rocky soils. However, the soil conditions at many construction sites are unclear, for example because the soil is composed of different layers with varying layer thicknesses, or because different soil zones contain rock, gravel, sand, clay, and cavities.

[0006] When constructing larger structures, it is therefore common practice to conduct test drilling at several locations on a building site to gain more detailed knowledge of the exact soil structure. Based on the individual test drillings, a soil model is then calculated, which forms the basis for the design of the building foundation, including precautionary safety margins. Particularly on construction sites with non-homogeneous soil, the soil model thus determined can sometimes deviate significantly from the actual soil conditions. In such a case, increased safety margins must generally be included in the foundation design. However, these can lead to significantly increased costs, for example, due to an increase in the number and / or size of foundation piles, anchors, reinforcing bars, and increased quantities of concrete.

[0007] In addition, there is a problem in that, despite appropriate safety margins, unexpectedly large deviations between the soil model and the actual soil conditions can cause long-term damage to the structure and also shorten the service life of a structure.

[0008] Document EP 3 109 365 A1 discloses a method for monitoring a building foundation in a soil for a structure, wherein: - soil parameters are determined for the soil; - based on the determined soil parameters, a preliminary soil model is calculated by means of a computer unit, on which model the design of the building foundation is designed, taking into account the specified data of the structure to be erected; - during the construction of the building foundation, measured values ​​for settlements, deformations and / or forces on the building foundation or the structure are recorded by means of measuring devices; - the measured values ​​are fed to the computer unit, which checks whether the measured values ​​are consistent with the previous soil model; and - if the measured values ​​are not consistent with the previous soil model, the computer unit calculates a subsequent soil model in which the measured values ​​are consistent with the new soil model;whereby the preceding soil model is compared with the subsequent soil model to determine the extent to which the specified foundation data have been achieved.

[0009] The invention is based on the Task The aim is to provide a method and an arrangement which enable particularly reliable monitoring of the condition of a building foundation.

[0010] The object is achieved, on the one hand, by a method having the features of claim 1 and, on the other hand, by an arrangement having the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims.

[0011] According to the invention, a method for monitoring a building foundation in the ground for a structure is provided, wherein soil parameters are determined for the soil, based on the determined soil parameters, a preliminary soil model is calculated by means of a computer unit, on the basis of which model the design of the building foundation is designed taking into account the specified data of the structure to be erected, during and / or after the construction of the building foundation, measured values ​​for settlements, deformations and / or forces on the building foundation or the structure are recorded by means of measuring devices, the measured values ​​are fed to the computer unit, which checks whether the measured values ​​are consistent with the previous soil model, and if the measured values ​​are not consistent with the previous soil model, a subsequent soil model is calculated by the computer unit, in which the measured values ​​are consistent with the new soil model.

[0012] The invention is not limited - as is the case with classical monitoring methods - to recording measurement data on a building foundation with a structure and comparing the measurement data with limit values ​​to determine whether a building foundation or a structure still behaves in an expected and permissible manner or whether changes occur which make it necessary to initiate safety measures.

[0013] The method according to the invention goes significantly beyond previously known methods in terms of monitoring. The method according to the invention checks whether the measured values ​​of the sensors on the building foundation or the structure are consistent with the soil model on which the design of the building foundation is based. If these measured values ​​lie within the expected value range determined from the previous soil model, the structure is deemed to be in correct condition. If one or more measured values ​​on the building foundation or the structure show unexpected or excessive deviations, even if the individual values ​​are not critical or problematic for the structure, the method according to the invention can be used to calculate a new subsequent soil model in which the current measured values ​​are consistent with the mathematically expected values ​​or are within the expected value range.Based on this new subsequent soil model, a recalculation or repeated calculation of the building foundation can then be carried out and it can be checked whether it still corresponds to the specified data for the building.

[0014] In the method according to the invention, measured values ​​from the building foundation or a structure are used to determine a refined soil model. This refined and thus more realistic soil model can then be used to assess the extent to which the building foundation meets the requirements.

[0015] It can therefore be considered a basic idea of ​​the invention to use measurement data from a building foundation and possibly a building in order to draw conclusions about the soil conditions and to refine an original or previous soil model and align it more closely with reality.

[0016] According to the invention, the preceding soil model is compared with the subsequent soil model to determine the extent to which the specified foundation data has been achieved. In particular, the computer unit can then determine or suggest structural measures to achieve or ensure that the specified data or requirements are met in the new soil model.

[0017] It is particularly expedient for the specification data to include the load-bearing capacity and / or service life of the building foundation or structure. In particular, the load-bearing capacity of a building foundation is a key specification that must be met for the erection of a structure on the building foundation. Particularly in the case of dams, which are often also provided with perimeter walls in the ground, the service life of both the dam and the perimeter walls in the ground, which are also to be regarded as a building foundation within the meaning of the invention, is a key specification factor. Especially in the case of such structures or construction projects, more precise knowledge of the soil can lead to significant extensions or shortening of the service life. Especially in the case of dams, reliable information on the expected service life can influence the type and number of maintenance and / or renovation measures as well as the premium amount for necessary building insurance.

[0018] In principle, the soil parameters for determining the first soil model can be determined in any suitable way, for example, through empirical values ​​from the area in which the construction site is located or through findings from other comparable construction projects in the area. According to one embodiment of the invention, it is particularly advantageous for the soil parameters to be determined through soil investigations, in particular test drilling. In particular, core drilling can be performed, whereby the soil structure can be determined based on the obtained core samples. Furthermore, drilling with probes or soundings from the soil surface can also be carried out to determine soil parameters.

[0019] It is also particularly useful for soil parameters to include the type, structure, and size of soil layers, as well as soil bearing capacity. This may also include the inclusion of a rock horizon in the soil. This allows for a particularly accurate and realistic determination even for the first soil model to be calculated.

[0020] Any type of suitable measuring device can be used to detect changes to the building foundation or the structure. According to a further development of the invention, it is particularly expedient for sensors, in particular strain gauges and / or load cells, to be installed on or in the building foundation and / or the structure as measuring devices. These sensors can record measurement data from the time of installation and over a long period of several years or decades, allowing reliable conclusions to be drawn about the condition of the building foundation or the structure.

[0021] Depending on the installation situation, the measuring devices can be connected to the computer unit or a transmitter unit via a wired connection. A particularly flexible arrangement according to an embodiment of the invention consists in the measuring devices being connected to the computer unit wirelessly. The measuring devices can thus be queried continuously or at predetermined intervals by a central computer unit or a mobile computer unit. It can be particularly expedient for the measuring devices to be completely or largely energy self-sufficient, for example with a lifetime battery. Furthermore, it can be advantageous for the measuring devices to be equipped with a transponder which, in response to an incoming signal that simultaneously transmits the necessary energy, carries out a measurement and / or transmits measurement data to the computer unit via a transmitter unit.

[0022] Particularly reliable monitoring of a structure or building foundation is achieved by repeatedly carrying out the process, especially at regular intervals. If measured values ​​are obtained that indicate no changes or changes that are expected based on the previous soil model, no further calculations are required, as the structure or building foundation is in proper condition. However, if the transmitted measured values ​​​​indicate changes outside the permissible range, the computer unit checks whether and to what extent the previous soil model needs to be refined or corrected. This then produces a subsequent soil model, which is used to once again check the design of the structure and calculate the extent to which all relevant specification data have been met, even taking the new soil model into account.In principle, the method according to the invention can be used in such a way that the subsequent soil models are only carried out after completion of a building foundation or the building as a whole. However, according to a further development of the invention, it can be particularly cost-effective if, when the measured values ​​are recorded while the building foundation is being constructed, the subsequent soil model is taken into account for the design of the building foundation in subsequent construction phases. Particularly for larger buildings that are constructed in individual construction phases, the method according to the invention can thus already process findings and measurement results for a first completed construction phase to determine whether and to what extent the previously underlying soil model has been determined realistically.In this way, refined soil models can be taken into account when considering subsequent construction phases, such as the design of foundation piles, retaining walls, back anchors, etc.

[0023] According to the invention, structural safety is improved by the computer unit issuing a warning if the specified data for the structural foundation are no longer met in the subsequent soil model. In such a case, remedial or safety measures can be taken to ensure the safety of the structure and, if necessary, its users. For example, additional foundation piles or reinforcements can be installed if necessary. The structure could also be relieved of load through load-relief measures, thus counteracting the risk of excessive stress.

[0024] The invention further relates to an arrangement for monitoring a building foundation in a soil for a building according to independent claim 9.

[0025] With this arrangement, in particular, the method according to the invention described above can be carried out. The advantages described above can be achieved.

[0026] The invention is further explained below using flowcharts of preferred embodiments. The drawings show: Fig. 1 shows a first schematic flow diagram for the method according to the invention; and Fig. 2 shows a further schematic flow diagram for a further development of the method according to the invention.

[0027] In Fig. 1The determination of the soil model, referred to here as the calculation model, is further clarified. Based on specified soil parameters, which may include a stiffness modulus or specific gravity of the soil and soil shear parameters, as well as environmental loads and geometric conditions, such as the thickness of soil layers, an initial soil model is calculated.

[0028] Furthermore, measurement data or measured values, for example, regarding deformations, settlements, anchor and lateral forces, can be recorded by appropriate sensor devices on the building foundation and the structure itself, which may also include the construction site and the subsoil. These measurement data or measured values, indicated as d0, are compared according to the inventive method with the expected measured values ​​d, which are theoretically derived from the calculation model. If a difference between the theoretically determined target values ​​d and the actually measured measured values ​​d0 lies within a tolerance eps, the input soil parameters are confirmed. In this case, the soil or calculation model is not recalculated.

[0029] However, if the difference between the target values ​​and the actual values ​​exceeds the specified tolerance range eps, optimization algorithms are carried out by a computer unit in which the previously assumed soil parameters are changed until a subsequent soil model or calculation model is created based on changed soil parameters mi, which more realistically reflects the actual conditions of the soil.

[0030] The new soil model or calculation model thus determined can then be Fig. 2can be used for a retrospective or recalculation of the design of the foundation or structure. First, the original design variables relating to the design, which for excavation support could be, for example, the installation depth, number, length, and position of anchors, the diameter and spacing of a pile wall, and the thickness of a diaphragm wall, are reviewed and recalculated based on the new calculation model.

[0031] The computer unit can specify a minimization of settlements and internal forces in walls, floor slabs, and foundation elements, as well as overall costs, as well as a maximization of structural safety. Based on these specifications, the computer unit can use multi-criteria optimization algorithms to calculate, for example, for subsequent construction phases, whether design variables can or must be changed under the specified criteria. This can, for example, achieve a material-optimized, cost-effective, and / or particularly safe structural design.

Claims

1. Method for monitoring a structural foundation in a ground for a structure, wherein - ground parameters are determined for the ground, - based on the determined ground parameters a preliminary ground model is calculated by means of a computer unit, on which a design of the structural foundation is laid out taking into consideration specification data of the structure to be erected, - during and / or after the production of the structural foundation measured values relating to settlements, distortions and / or forces on the structural foundation or the structure are recorded by means of measuring means, - the measured values are forwarded to the computer unit which checks if the measured values are consistent with the preliminary ground model, and - if the measured values are not consistent with the preliminary ground model, a subsequent ground model, in which the measured values are consistent with the new ground model, is calculated by the computer unit, wherein the preliminary ground model is compared with the subsequent ground model as to what extent specification data of the foundation are met, and wherein a warning is issued by the computer unit if specification data for the structural foundation are no longer met in the subsequent ground model.

2. Method according to claim 1, characterized in that the specification data comprise a load-bearing capacity and / or lifespan of the structural foundation or the structure.

3. Method according to any one of claims 1 to 2, characterized in that the ground parameters are determined through ground analyses, in particular test drillings.

4. Method according to any one of claims 1 to 3, characterized in that the ground parameters comprise type, composition and size of ground layers as well as a load-bearing capacity of the ground.

5. Method according to any one of claims 1 to 4, characterized in that as measuring means sensors, in particular strain gauges and / or load cells, are mounted on or in the structural foundation and / or the structure.

6. Method according to any one of claims 1 to 5, characterized in that the measuring means are wirelessly connected to the computer unit.

7. Method according to any one of claims 1 to 6, characterized in that the method is carried out repeatedly, in particular at regular intervals.

8. Method according to any one of claims 1 to 7, characterized in that when recording the measured values, while still producing the structural foundation, the subsequent ground model is taken into consideration for the design of the structural foundation in subsequent construction stages.

9. Arrangement for monitoring a structural foundation in a ground for a structure, for carrying out the method according to any one of claims 1 to 8, having - a computer unit, by which, based on determined ground parameters, a preliminary ground model can be ascertained, on the basis of which a design of the structural foundation takes place in consideration of specification data, and - measuring means on the structural foundation or a structure, wherein settlements, distortions and / or forces on the structural foundation or the structure can be recorded by the measuring means, wherein - the computer unit has a data connection to the measuring means for the transmission of measured data and by the computer unit a check can be made as to whether the measured values are consistent with the first ground model, - wherein by the computer unit a subsequent ground model can be calculated, in which the measured values are consistent with the subsequent ground model, if the measured values are not consistent with the preliminary ground model, - wherein by the computer unit the preliminary ground model is compared with the subsequent ground model as to what extent specification data of the foundation are met., and - wherein a warning can be issued by the computer unit if specification data for the structural foundation are no longer met in the subsequent ground model.