Research of the prediction method and environment conservation due to coal mining subsidence in North China

为了解决开采沉陷问题，我们与中国的领先科研院所合作开展了这一项目。在合作期间，我们邀请中国的研究人员到日本，并派我们的研究人员到中国调查地面下沉的现状。对调查研究成果进行了总结，由于中国矿区采煤以地下开采为主，因此认为采煤沉陷是不可能的。影响面积每年增加约1.33亿~2亿m~2。一般情况下，对地表结构的影响主要有：沉陷、坡度、曲率、水平移动和纵向应变。事实上，每个影响因素都是交替起作用的。在很多地区，中国境内都有不少低坡度河床的河流。塌陷可能会影响整个流域，并可能出现排水等问题。九州大学开发了一种新的分析系统，利用地理信息系统(GIS)预测地面沉降过程。该方法已应用于中国北部的两个有代表性的地区。准确预测了开挖过程中的沉降量，并对其对铁路、桥梁等地表结构的影响进行了评估。提出了一些想法，并对开采方案进行了修改，以减少沉陷的影响。在煤矿开采的开采规划中，应正确评估相应的影响和影响，并制定相应的对策。围绕当今创造良好新环境的主题，研究成果可用于建立地质环境保护体系，实现资源开发与环境的协调发展。

In order to solve subsidence problem due to mining, we cooperate with the leading research institutes in China to carry out this project. During the cooperation, we invite the Chinese researchers to Japan, and send our researchers to China to investigate the current status of subsidence. The investigation and studied results are summarized.Because most of the coal mining in China is underground mining, it is believed that the subsidence is unavailable. The influenced area is about 133〜200 million m^2 increasing every year. Generally, the corresponding influences to the surface structure are discussed as follows : subsidence, slope, curvature, horizontal movement and longitudinal strain. In fact, each influencing factor works alternatively. In many areas, there are a lot of rivers with a low gradient riverbed in China. Subsidence may influence the whole watershed area and some problems such as drainage may take place. Kyushu University has developed a new analysis system to predict the subsidence procedure by using Geographic Information System (GIS). The method has been applied to two representative districts in North China. The subsidence because of excavation process is precisely predicted, and its influences to surface structure such as the railway and bridge are assessed. Some ideas have proposed and the excavation planning is modified to reduce the subsidence impact.In the excavation planning of coal mining, the corresponding influences and impact should be evaluated correctly and the corresponding counter measures have to be prepared. Concerning the theme of creating a good new environment nowadays, the research results could be used to establish a geo-environment conservation system, and the development of resources could be in harmony with the environment.