In November 2016 a seismic station "Severnaya Zemlya" with code SVZ was installed on the Severnaya Zemlya archipelago (Bolshevik island, research facility "Ice base "Baranov's cape") by joint efforts N. Laverov Federal Center for Integrated Arctic Research (Arkhangelsk) and Arctic and Antarctic Research Institute (St. Petersburg). This station was included in the Arkhangelsk seismic network and a broadband set of CMG-6TD devices (Great Britain) was installed there.

Một số kết quả đánh giá sự ổn định của đập thủy điện Sông Tranh 2 và môi trường địa chất xung quanh bằng tổ hợp các phương pháp địa chấn ABSTRACT Some results of stability evaluation for the Song Tranh 2 dams and its surrounding geological environment by microseismic investigationsIn this paper the authors present the results of evaluation of stability for the Song Tranh 2 dam and its surrounding geological environment. The study is carried out by using two modifications of microseismic observation. For the first modification the data were collected along 5 profiles distributed on land surface of the dam area and its surrounding. In the second modification the measurements were concentrated in the dam location with the microseismic signals generated by rotation of turbines of the electric power plant as an additional source. In this case the investigated profiles are distributed both on the top surface of the dam as well as along the tunnels constructed inside the dam body.The high value of the relative intensity of microseismic signals (The ratio of the microseismic wave amplitudes in a certain frequency band recorded by the movement and fixed stations obtained in this study are allowed us to reveal a number of heterogeneity objects distributed in the dam and its surrounding geological environment with define depth. The technique is more effectivle in the detection of subvertical contact. The correlation with the geological -geophysical available data is indicated the heterogeneities mostly are taken places where distributed tectonic fault or underground weak section.It will be very useful if the technique is applied for the study of the same problem for the other hydroelectric power plants inVietnam.

Constructions along railway traffic lines are always exposed to vinrations generated by the passing transport. This sometimes leads to shifts in their state even threatening the comfort of the people that stay here. To estimate the magnitude of such effect one needs the frequency-amplitude chart of impacting vibrations. Current codes [1] are applied to the main types of buildings and state the acceptable level of magnitudes in wide frequency ranges. However, the code’s regulations are not enough to ensure the building’s stability as the real state of this building is not taken into account. This is especially true for the historical buildings near railroads. Majority of these are cult-related and are mostly damaged and need renovation. To correctly estimate an impact of vibrations one needs to measure addition tensions due to vibration in the construction’s body and to compare them with ones resistance material calculations. In other words, seismic vibrations emitted by trains act as a seismic signal, for which there are several established methods of evaluation. Finite elements simulations enables estimation of the distribution of static and dynamic loads so that the most vulnerable locations in the construction’s body are identified. Consequently the simulation can use experimentally recorded waves (spectra or accelerogramms) as the dynamic load. With the simulation stage set different model types are cycled until the satisfactory match is obtained as is shown in the paper. Importantly, we demonstrate how construction evaluation methods can be combined with applied seismic methods, which are being actively developed for the needs of soil and construction integrity evaluations.

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