CN201362861Y - Dynamic detection device for foundation restricting capability of civil engineering structure - Google Patents

Abstract

A dynamic detection device for foundation restricting capability of a civil engineering structure is characterized by the inclusion of a test unit (1) and a host computer analyzing unit (10). The test unit (1) comprises a sensor (2), an anti-aliasing filter amplifier (3), an A/D converter (4) and an output unit (5), and the host computer analyzing unit (10) comprises an FFT analysis module (7), a foundation constraint stiffness identification module (8) and a display and storage module (9). The host computer analyzing unit (10) sends the received data to the FFT analysis module (7) for FFT analysis to acquire the vibration base frequency of the structure before and after the loading, then the foundation constraint stiffness identification module (8) calculates the foundation constraint stiffness according to the FFT analysis, and the acquired results are displayed and stored by the display and storage module (9). The utility model solves the difficulty of measuring restrain capability of established foundations, and has the characteristics of convenience, accuracy and high efficiency.

Description

The civil engineering structure foundation restriction ability device for dynamically detecting

Technical field

The utility model relates to a kind of civil engineering structure foundation restriction ability detection technique, especially a kind of structure foundation in completing for use is carried out the device for dynamically detecting that restriction ability is measured, specifically a kind of civil engineering structure foundation restriction ability device for dynamically detecting.

Background technology

At present, along with China's rapid development of economy and and the raising of scientific and technological level, the design theory and the building technology of civil engineering structure constantly develop, and people have built civilian, industrial construction, tall and big overpass bridge, the urban viaduct of various ways and striden the bridge in river, river and bay.For superstructure, the basic engineering of civil engineering structure is more complicated, its mechanical durability research and the also more apparent difficulty of disease screening.Under ambient conditionss such as weathering, freezing and soil erosion, influenced by reciprocal wind load, the basic stress of structure changes between maximum pressure and pulling force, the minute crack that these power cause can quicken the corrosion on basis and cause foundation bearing capacity to reduce, thereby shortens the application life of structure.Some are built in structure on the soft foundation, and more or less because of certain reason (as relative settlement, variations in temperature) was subjected to damage, the subsidiary stress that wind load, service load and seismic (seismal cause has then been quickened the development of this damage in the operating period.Engineering structures to intact and no abnormal STRESS VARIATION also might cause bigger foundation displacement or unstability (the softening or liquefaction as saturated soil, slope failure) because of vibration.Engineering structures has suitably been selected the foundation bed size by its foundation capability, can guarantee that generally structure has enough degrees of safety when preventing ground shear failure, but under load action, foundation settlement takes place always, and abnormal foundation settlement distortion very easily causes cracking, the unstability of structure, forms dangerous structure.The deformation monitoring of nearly 10 years civil engineering structures shows that the distortion of civil engineering superstructure and the differential settlement of ground and formation accident are contacted directly.

The soil state of the art and the variation thereof of structure down is the important evidence of determining its mechanical characteristic and Engineering Reliability.The structure that causes owing to foundation deformation and the interaction of ground just become a major issue.As the main purpose of structure disease screening, in actual engineering survey, want directly to record engineering structures basic constraint rigidity and be difficult to.The method of traditional identification foundation restriction ability is based upon on the soil mechanics basis mostly, these soil mechanics statistical parameters can be in time with the different of the geology of each department and ambient conditions and change complex distribution and detection difficult.A kind of technology that can effectively measure foundation restriction ability in the structure of having built up is not arranged at present as yet.

Summary of the invention

The purpose of this utility model is to detect the problem that lacks effective means at having built up at present civil engineering structure foundation restriction ability, design that a kind of detections is effective, the scope of application extensive, enforcement makes things convenient for the civil engineering structure foundation restriction ability device for dynamically detecting.

The technical solution of the utility model is:

A kind of civil engineering structure foundation restriction ability device for dynamically detecting, it is characterized in that it is made of test cell 1 and host analysis unit 10, the signal output part of test cell 1 is connected with the signal input part of host analysis unit 10, and the signal that the 10 pairs of test cells 1 in host analysis unit measure is handled; Test cell 1 comprises sensor 2, anti-aliasing filtering amplifier 3, A/D converter 4 and output unit 5, the signal output part of sensor 2 links to each other with the signal input part of anti alias filter 3, the signal that sensor 2 is collected carries out amplification filtering, the signal output part of anti-aliasing filtering amplifier 3 links to each other with the signal input part of A/D converter 4, analog signal conversion is become data signal, the signal output part of A/D converter 4 links to each other with host analysis unit 10 by output unit 5, will be through the digital data transmission after 4 conversions of A/D converter in host analysis unit 10; Host analysis unit 10 comprises fft analysis module 7, foundation restriction rigidity identification module 8 and shows memory module 9, host analysis unit 10 is sent into the data that receive and is carried out fft analysis in the fft analysis module 7, structural vibrations fundamental frequency before and after obtaining loading, foundation restriction rigidity identification module 8 obtains the result and shows and the preservation data by showing with memory module 9 according to the restriction rigidity of the fundamental frequency calculating ground of fft analysis.

The beneficial effects of the utility model:

1, the utility model has been set up the kinetic measurement assessment technology that a kind of self-vibration fundamental frequency that only need record twice loading front and back structure can identify its foundation restriction ability first by a large amount of experiments and analytical calculation, for the foundation restriction ability judge of building up foundation structure provides convenience, data information on the other hand efficiently, and developed be applicable to the collection in worksite data and identification foundation restriction ability virtual test system, with advanced person's data acquisition and signal processing method, convenient and practical means are provided for the safety monitoring of ground in conjunction with flexible modular virtual integrated technique.

2, the utlity model has higher operational precision, wherein frequency analysis precision can reach 1%, and the foundation restriction ability accuracy of identification can reach 3%.

3, the utility model dependable performance is easy to use, and has very high precision, and the scope of application is extensive.

Description of drawings

Fig. 1 is the composition frame chart schematic diagram of the utility model checkout gear.

Fig. 2 is an analysis software flow chart of the present utility model.

The specific embodiment

Below in conjunction with drawings and Examples the utility model is further described.

As shown in Figure 1.

A kind of civil engineering structure foundation restriction ability device for dynamically detecting, it is made of test cell 1 and host analysis unit 10, the signal output part of test cell 1 is connected with the signal input part of host analysis unit 10, and the signal that the 10 pairs of test cells 1 in host analysis unit measure is handled; Test cell 1 comprises sensor 2, anti-aliasing filtering amplifier 3, A/D converter 4 and output unit 5, the signal output part of sensor 2 links to each other with the signal input part of anti alias filter 3, the signal that sensor 2 is collected carries out amplification filtering, the signal output part of anti-aliasing filtering amplifier 3 links to each other with the signal input part of A/D converter 4, analog signal conversion is become data signal, the signal output part of A/D converter 4 links to each other with host analysis unit 10 by output unit 5 (can adopt USB device to carry out transfer of data), will be through the digital data transmission after 4 conversions of A/D converter in host analysis unit 10; Host analysis unit 10 (can adopt laptop computer or conventional computer to be realized, corresponding calculated module software such as fft analysis module 7 are installed therein, foundation restriction rigidity identification module 8 grades can realize) comprise FFT (being Fourier transformation) analysis module 7, foundation restriction rigidity identification module 8 and demonstration memory module 9, host analysis unit 10 is sent into the data that receive and is carried out fft analysis in the fft analysis module 7, structural vibrations fundamental frequency before and after obtaining loading, foundation restriction rigidity identification module 8 obtains the result and shows and the preservation data by showing with memory module 9 according to the restriction rigidity of the fundamental frequency calculating ground of fft analysis.

Utilize said apparatus can press step and detect (as shown in Figure 2):

The first step: it is that data acquisition is prepared that sensor is set on detected structure, during concrete enforcement, if detect the foundation restriction ability of bridge pier, placement sensor on bridge pier then, if detect the foundation restriction ability of pile foundation, then in the cushion cap placement sensor, if detect open caisson or laying foundation foundation restriction ability in open caisson or caisson placement sensor;

Second step: the tested structural environment vibratory response of sensor acquisition that utilize to be provided with, and to carry out Fourier transformation be fft analysis (can adopt existing ripe software to carry out), obtains the self-vibration fundamental frequency omega of structure _1,0, be assumed to be M by the quality on geodesic structure top this moment ₀

The 3rd step: carry out loading the first time on by geodesic structure, this moment, the quality on structure top was assumed to be M ₁Gather this moment by the response of the ambient vibration of geodesic structure, and to carry out Fourier transformation be fft analysis, obtain the self-vibration fundamental frequency omega when being loaded by the first time of geodesic structure _1,1

The 4th step: carry out loading the second time on by geodesic structure, be assumed to be M by the quality on geodesic structure top this moment ₂Gather this moment by the response of the ambient vibration of geodesic structure, and to carry out Fourier transformation be fft analysis, the self-vibration fundamental frequency omega when load the second time that obtains structure _1,2

The 5th step: record the self-vibration fundamental frequency omega with three times _1,0, the self-vibration fundamental frequency omega when loading for the first time _1,1, the self-vibration fundamental frequency omega when loading for the second time _1,2And imported following three restriction abilities by the sole mass of geodesic structure, rigidity, material property parameter and assess the simultaneous formula, can calculate the translation restriction rigidity k of structure ₁, rotational restraint rigidity k ₂With vertical restriction rigidity k ₃, for providing, tested structure foundation safety monitoring calculates required foundation:

$\left\{\begin{array}{c}\frac{1}{{\mathrm{\ω}}_{\mathrm{1,0}}^2}=\frac{M_0+m}{k_1}+\frac{(M_0+m)\mathrm{AE}}{k_{3}l}+\frac{J_R+J_{M0}}{k_2}+M_0\mathrm{\α}+\mathrm{\β}\\ \frac{1}{{\mathrm{\ω}}_{\mathrm{1,1}}^2}=\frac{M_1+m}{k_1}+\frac{(M_0+m)\mathrm{AE}}{k_{3}l}+\frac{J_R+J_{M1}}{k_2}+M_1\mathrm{\α}+\mathrm{\β}\\ \frac{1}{{\mathrm{\ω}}_{\mathrm{1,2}}^2}=\frac{M_2+m}{k_1}+\frac{(M_0+m)\mathrm{AE}}{k_{3}l}+\frac{J_R+J_{M2}}{k_2}+M_2\mathrm{\α}+\mathrm{\β}\end{array}\right.$

In the formula: J _R---by the dynamic moment of inertia of geodesic structure;

J _M0, J _M1, J _M2---be respectively by the initial mass on geodesic structure top, load the back for the first time, load the dynamic moment of inertia of the quality of upper back for the second time tested structural base;

A, l---by the sectional area of the horizontal section of geodesic structure and calculated length (highly);

M---tested architecture quality;

The modulus of elasticity of E---structural meterials;

α, β only be respectively with by the relevant coefficient of geodesic structure self material, calculate gained by following formula:

$\mathrm{\α}=\frac{l^3}{3\mathrm{EI}}+\frac{8l}{k^{\′}\mathrm{GA}{\mathrm{\π}}^2},$ $\mathrm{\β}=\frac{16(3\mathrm{\π}-8)\mathrm{rA}{l}^4}{{\mathrm{\π}}^5\mathrm{gEI}}+\frac{{4\mathrm{rl}}^2}{{\mathrm{\π}}^2{k}^{\′}\mathrm{gG}}$

EI is by the bending stiffness of geodesic structure in the formula, and g is an acceleration of gravity, and G is by the shearing rigidity of geodesic structure, and r is by the weight density of geodesic structure, and 1/k ' is the shear stress distribution coefficient, square-section k '=5/6, circular cross-section k '=9/10.

In three equations of simultaneous, M ₀, M ₁, M ₂, J _M0, J _M1, J _M2Can calculate A, l, α, β, J according to known superstructure design drawing and load mass _RBeing the design parameters of bridge pier, cushion cap, open caisson or caisset, also is known parameter, ω _1,0, ω _1,1, ω _1,2Can obtain by the environmental response signal analysis of sensor acquisition equipment collection bridge pier, cushion cap, open caisson or caisset.Therefore expression formula has only k ₁, k ₂, k ₃Be unknown parameter to be identified, and remaining parameter all can be expressed as the known parameter of structure self.Therefore load by artificial, can list 3 form is identical but mutual incoherent equation constitutes identification k ₁, k ₂, k ₃The necessary and sufficient condition of three foundation restriction rigidity.Obtaining k ₃Three foundation restriction rigidity k ₁, k ₂, k ₃After utilize existing theory and the further computer ground of design formulas whether to be in a safe condition again judgement so that in time take appropriate measures, guarantee safety.

The utility model does not relate to the part prior art that maybe can adopt all same as the prior art to be realized.

Claims (1)

1, a kind of civil engineering structure foundation restriction ability device for dynamically detecting, it is characterized in that it is made of test cell (1) and host analysis unit (10), the signal output part of test cell (1) is connected with the signal input part of host analysis unit (10), and handle the signal that test cell (1) measures host analysis unit (10); Test cell (1) comprises sensor (2), anti-aliasing filtering amplifier (3), A/D converter (4) and output unit (5), the signal output part of sensor (2) links to each other with the signal input part of anti alias filter (3), the signal that sensor (2) is collected carries out amplification filtering, the signal output part of anti-aliasing filtering amplifier (3) links to each other with the signal input part of A/D converter (4), analog signal conversion is become data signal, the signal output part of A/D converter (4) links to each other with host analysis unit (10) by output unit (5), will be through the digital data transmission after A/D converter (4) conversion in host analysis unit (10); Host analysis unit (10) comprises fft analysis module (7), foundation restriction rigidity identification module (8) and shows memory module (9), host analysis unit (10) is sent into the data that receive in the fft analysis module (7) and is carried out fft analysis, structural vibrations fundamental frequency before and after obtaining loading, foundation restriction rigidity identification module (8) obtains the result and shows and the preservation data by showing with memory module (9) according to the restriction rigidity of the fundamental frequency calculating ground of fft analysis.

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