Safety Assessment Of Bridge Structure On The Basic Blasting

Currently, blasting technique is widely used in engineering field, and hasaffected or destroyed the structure which is nearby more or less. Previously,technical specifications are mostly used to evaluate the safety assessment ofstructures under the action of explosion seismic wave, but the bridges rarely.However, bridge is important infrastructure in transportation hub, its safety hascertain affect on people’s life safety and economic construction, so, the safetyassessment of bridge structure highlights its importance and indispensability.First, this paper studies related theoretical knowledge of explosion seismicwave, and the similarities and differences between traditional continuous girderbridge and extradosed cable-stayed bridge. Then, it analyses the condition ofexternal force and gets balanced form of the structure. On the basis of above, thispaper analyses the dynamic performance of two bridges under hard strengthblasting and low strength blasting and compares the results, points out a new andreasonable method about safety assessment, provides scientific reference standardand data for subsequent designing of blasting and safety assessment of bridges.1. The paper has studied explosion seismic wave in detail based on vibrationparameters, propagation law and influencing factor etc. and elaborate thesimilarities and differences between natural earthquake and explosion seismicaccording to comparing the results of them. It introduces the basic theories,methods of corresponding calculation and formulas about dynamic analysis ofstructure.2. According to the engineering drawings, continuous girder and extradosedcable-stayed bridges are simulated by finite element software ANSYS andMidas/civil. The paper does the modal analysis of two bridges and compares theinherent vibration characteristics.3. The paper inputs the encouragement to the model with actual blast responsespectrum curve and natural earthquake response spectrum curve, analyses andcompares the dynamic response of bridges under natural earthquake and lowstrength blasting, points out the defects of traditional safety assessment method,advices to evaluate the safety with bursting strength. 4. It analyses and compares the dynamic response in detail under the conditionof hard strength blasting seismic wave, assesses the safety of two bridges,researches the mutual reference function of the evaluation scheme about twobridges and verifies its rationality, at the same time, making up for the blank ofsafety assessment.