Vibration compaction characteristics of rock filling embankment

The dynamic model experiment of the rock filling embankment was carried out to investigate the vibration compaction mechanism. The rock filling materials were compacted by the plate-vibrated compactor, and the characteristics of the rock filling materials, such as settlement, pressure change and response waveform, were measured by the dynamic earth pressure gauge and accelerometer. Moreover, a new method for detecting the compactness of the rock filling embankment was proposed based on the maximum dry density and modulus of deformation. The results show that the process of vibration compaction includes compact, elastic deformation and loose stages, and the vibratory pressure transfers to the surroundings from the vibration center in non-linear rule. Furthermore, the test results obtained by the present method are basically in agreement with those obtained by the traditional method, and the maximum relative error between them is about 0.5%.     

面向Flink流处理框架的主动备份容错优化

针对Flink任务出现故障后因为全局卷回使流处理作业恢复效率低的问题,提出基于缓存队列的容错策略. 在作业中找出恢复时间最长的算子作为关键算子,将其处理过的数据存储到缓存队列中,并为其进行主动备份,备份算子同时接受来自上游的数据以达到在故障后作业可以瞬时恢复的效果. 为了解决主动备份带来的额外消耗,提出数据过滤算法,备份算子在每次处理数据前会到缓存组件中检索当前数据,以判断是否继续处理. 当Flink算子自身出现故障后,利用策略中的缓存队列与Flink的JobManager将故障发生时的数据信息发送给备份算子,在备份算子接收到数据后,实现即时恢复的效果. 利用4项评价指标对策略进行评估,结果表明,与Flink1.8的故障恢复模式相比,所提策略在Flink任务故障恢复速度上有显著提升,当故障次数分别为1、2、3、4时,恢复效率分别提高56.3%、51.3%、46.2%和45.8%;而在处理时延、CPU利用率以及内存使用率方面仅产生极小的代价.     

粮食平房仓杂填土场地换填垫层与螺旋钻孔灌注桩基础设计方案的比较分析

结合某国家粮食储备库工程,对杂填土场地平房仓地基处理的换填垫层法和螺旋钻孔灌注桩进行对比分析,提出了采用螺旋钻孔灌注桩的基础方案,经实践验证达到了安全适用、经济合理的设计效果.