After discovering the principles linking dynamic stiffness to static stiffness and internal force in the tie bar, an international patent has been registered (Fig. 5.1).

Fig. 5.1
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Patent extract

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Calibration.

Establishing the relationship between dynamic stiffness and tensile force in the tie rod that needs to eliminate the dynamic stiffness value for example of the retaining wall and other elements that can modify the total value of the stiffness (Fig. 5.2).

Fig. 5.2
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Source Rincent BTP—France

Simultaneity of static and dynamic tests.

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The test results obtained in Fig. 29, for example, led to the following analyses that relate the square root of dynamic stiffness to tensile force (Fig. 5.3).

Fig. 5.3
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Square root of dynamic stiffness as a function of force

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The following figure collects a portion of the tension force results for a wall with 590 ties rod (Fig. 5.4).

Fig. 5.4
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Force results table in tons

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Establishing the relationship of dynamic stiffness and tensile force in the tie that needs to eliminate the value of dynamic stiffness for example for the retaining wall and other elements that can modify the stiffness. The wall with beams is a very different configuration with a high inertia (Figs. 5.5 and 5.6).

Fig. 5.5
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Source Rincent BTP—Recife

Site overview.

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Fig. 5.6
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Source Rincent BTP—Recife

Detailed view of the concrete beams.

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This method cannot be used, for example, to measure force of a pre-stressed beam cable or a bridge deck. The only element that will be measured is the inertia of the beam or deck.

A study of a quay wall of a canal of a nuclear power plant shows that one tie, no. 2, was broken. The calculated average value of the internal force was 53 tons (Fig. 5.7).

Fig. 5.7
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Effort distribution force (t) Tie rod number

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