TSP在高地温—高地应力隧道地质预报中的问题及改进

Problems and improvements of Tunnel Seismic Prediction ingeological prediction of tunnels under high geotemperature and high in-situ geostress

正在建设的川藏铁路有大量隧道具有高地温、高地应力特征,如何提高高地温—高地应力隧道超前地质预报的精度是工程建设面临的一大难点。以TSP法超前地质预报为例,分析该方法在高地温—高地应力隧道探测主要存在两方面的问题:一方面是采用乳化炸药和塑料导爆管在高岩温炮孔中激震时易发生拒爆、哑炮及瞎炮,影响数据采集;另一方面是数据处理未考虑高地应力隧道已开挖区和未开挖区的波速变化。针对这些问题,提出六点改进措施,即:研制绝热保温袋起爆药包、建立基于多元地质信息的智能工程评价体系、改变TSP的激震方式、推广超前地质预报新技术新方法、研发适用于TBM的超前地质预报系统、改善地质预报组织管理。这些措施可为高地温—高地应力地区隧道超前地质预报的高效探测提供借鉴。

The Sichuan-Tibet Railway under construction has a large number of tunnels under high geotemperature and high in-situ geostress.How to improve the accuracy of advanced geological prediction of these tunnels is a major difficulty in railway construction.Taking the Tunnel Seismic Prediction(TSP)method for advanced geological prediction as an example,analyses reveal that there are two major problems in the detection of the tunnels.On is that the use of emulsion explosives and plastic detonating tubes in blastholes under a high rock-temperature is liable to cause misfires,thus affecting data acquisition.The other is that the wave velocity differences between the excavated and unexcavated areas of tunnels under high in-situ geostress are not considered in data processing.Targeting these problems,this paper proposes six improvement measures,namely researching and developing detonation packs with a thermal insulation bag,establishing intelligent engineering assessment systems based on multiple geological information,changing the models of shock initiation of the TSP,popularizing new technologies and methods of advanced geological prediction,researching and developing advanced geological prediction systems suitable for Tunnel Boring Machines(TBMs),and improving the organizational management of geological prediction.All these measures can provide references for efficient detection of advanced geological prediction of tunnels in areas with high geotemperature and high in-situ geostress.