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Big data are widely used in various fields. However, the application of big data is rare in the study of predicting surface subsidence caused by underground mining. Traditional research has the problem of oversimplifying geological mining conditions. In the context of geospatial big data, a data-intensive FLAC3D (Fast Lagrangian Analysis of a Continua in 3 Dimensions) model is proposed in this paper based on CAD software (Rhinoceros) and borehole logs. The data-intensive FLAC3D model was developed using Rhinoceros software to visualize borehole logs in three dimensions. In the three dimensional modeling process, based on the characteristics of the FLAC3D model and borehole logs, we developed a method to handle geospatial big data and were able to make full use of borehole logs. The effectiveness of the proposed method was verified by comparing the results of the traditional method, proposed method and 70 observation points on the surface. This study shows that the proposed method has obvious advantages over the traditional prediction results. Compared with the traditional prediction results, the relative error of the surface maximum subsidence predicted by the proposed method decreased by 93.7% and the standard deviation of the prediction results (which was 70 points) decreased by 39.4%, on average. The proposed method is the first method to geospatial big data into the mining subsidence prediction research, which is of great significance for improving the accuracy of mining subsidence predictions.

Mine surveying is an important part and infrastructure protection of mine production and mine construction, and it is also very important basic work of coal mine safety production. This article summarized the development process of China's mine surveying for 60 years, the development process of China's mine surveying was from Transit Times which angling and distancing separately to Electronic Total Time which angling and distancing combo. Today, China's mine surveying has developed into an information science which combines with measurement and optoelectronic technology, computer technology, global positioning system (GPS), geographical information system (GIS) , remote sensing (RS) , D-InSAR and Unmanned Aerial Vehicle Remote Sensing with the rapid development of science and technology. This paper also analyzed the development status, opportunities and challenges-digital of China's mine surveying , and pointed out its development direction and what measures should be taken.

The performance of resisting foundation displacement of a typical single return circuit transmission tower under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement was analyzed by finite element modeling. Results showed that stability failure of single steel angle represents tower’s limit state under foundation displacement. And the corresponding foundation displacement limits were calculated. Results indicate that foundation pull condition is more dangerous than press condition. Under complex foundation displacement conditions, foundation horizontal displacement is primary factor leading to stability failure of towers. Under foundation press condition and pull condition, wind load is primary factor. Result also indicates that, tower does not fail when foundation displacements are smaller than 1.25% (under foundation press condition and pull condition) or 0.5% (under single foundation sink condition) of tower root distance.

Mining subsidence damage is the main factor of restricting coal mining under buildings. To control or ease effectively the degree of mining subsidence and deformation is essential to resolve this problem. Through analyzing both advantages and disadvantages of some technologies such as mining with stowing, partial extraction and grouting in separated beds of overburden, we used the principle of load replacement and propose a “3-step mining” method, a new pattern of controlling mining subsidence, which consists of: strip mining, i.e. grouting to fill and consolidate the caving zone and retained strip pillar mining. The mechanism of controlling mining subsidence by using the “3-step mining” pattern is analyzed. The effect of the control is numerically simulated. The preliminary analysis shows that the “3-step mining” can effectively control ground subsidence and deformation. By using this method, the ground subsidence factor can be controlled to a value of about 0.25. Coal recovery can reach 80%–90%. Coal mining without removing surface buildings can be realized and the economic loss resulting from ground subsidence can be greatly reduced.

Gangue backfilling?which combines subsidence diminution with emission reduction?is a new method for controlling surface subsidence, and it could be widely used in coal mining under buildings and water body, disposing of the solid waste, governing environment of mining areas and so on. This paper analyzes the effect of gangue backfilling on alleviating the surface subsidence disasters and lowering the height of strata destruction in theory. Study shows that the subsidence coefficient of coal mining with gangue backfilling technology is between 0.21 and 0.28, and this method can decrease approximately 43% of the height of strata destruction. Using the technology of coal mining with gangue backfilling, not only the waste can be disposed appropriately, but also it can effectively protect buildings and some natural resources such as water and land so as to achieve the goal of coordinated development of coal mining and environmental protection.