Applicability of small resistance fastener on long-span continuous bridges of high-speed railway

Ballastless tracks have been widely applied in high-speed railway (HSR). The adaptability research between continuous welded rails (CWR) and long-span bridges of HSR is of great practical engineering significance. Based on the HSR long-span continuous bridges, the integrative spatial finite element model of track-bridge-pier-foundation system was established with the nonlinear spring element simulating the longitudinal resistance between track and bridge. Comparative study on the various additional longitudinal forces of CWR using the common fasteners and small resistance fasteners was carried out. Analysis results indicate that the additional expansion forces and additional rail-breaking forces in long-span ballastless continuous girders can be reduced evidently by 40% 50% after adopting small resistance fasteners, but lead to greater rail broken gap. The small resistance fasteners have little influence on the additional force only caused by vertical load, but can reduce the additional force caused by vertical load combined with braking load by over 10%. Besides, transient analysis method is proved to be more accurate and safe in calculating additional longitudinal forces when the train running or braking on the bridge, compared with the traditional static method.

对老病残罪犯扩大适用假释制度的思考

老病残罪犯是监狱罪犯中的特殊群体，是危及监管安全的高危人群，是监管改造的难点、重点。但受行政考核、假释条件、社区矫正、标准掌握、执法观念、执法顾虑及社会舆论等因素影响，老病残罪犯普遍存在假释难、假释率低等问题，因此，为构建和谐社会，落实宽严相济的刑事司法政策，保障罪犯权利，降低行刑成本，调动和促进罪犯改造的积极性，依据《刑法修正案（八）》的相关规定，有必要进一步规范假释条件，完善呈报程序及标准，实行社区矫正。