考虑充填顺序与后壁黏结力的采场充填计算统一解

以统一强度理论的平面应变抗剪强度公式为基础,合理考虑中间主应力效应、充填顺序、后壁黏结力和顶部超载等综合影响,推导大深宽比采场充填计算时充填料的所需黏聚力统一解和充填体的安全系数统一解,并结合工程算例给出简化公式以及示范计算,继而分析其可比性,最后探讨各因素的影响特性。研究结果表明:本文统一解涵盖了众多的已有解答与新准则解答,具有广泛的理论意义和很好的可比性;2种不同用途的充填计算公式都十分简单,便于实际工程选择及使用;中间主应力效应、充填顺序和后壁黏结力对采场充填计算的影响均很显著,指出现有文献的结果偏于保守,对这3种因素的有效利用可产生重要的经济效益;顶部超载的影响亦不容忽视,应慎重估计顶部超载以实现充填优化计算。

立式离心场下钛合金熔体充填及凝固过程研究(英文)

研究立式离心场下不同铸造工艺参数对钛合金熔体的充填及凝固缺陷形成的影响。结果显示,立式离心场下得到的钛合金铸件质量优于重力场下的铸件。立式离心场下,合金熔体由于受离心力和科氏力的作用,沿着与旋转方向相对的型壁进行充填,且熔体的截面面积随充填长度的增加而逐渐减小,但是在内浇口处由于速度降低导致截面面积有所回升。此外,铸型的旋转方向,旋转半径及旋转速度直接影响铸件缺陷的形成。旋转方向直接影响合金熔体的充填顺序,进而影响合金熔体的凝固顺序及缺陷位置。实验结果显示,旋转半径及旋转速度的增加有利于减少铸件的缺陷体积。

过渡期采空区充填优化与承压矿柱协同开采技术应用

铜坑矿92号矿体自2000年开始采用组合式崩落法进行规模化开采。由于开采环境复杂,地压活动严重,大多承压矿柱难以回收。针对崩落转充填法过渡期矿山实际情况,在数值模拟分析基础上,提出了合理的充填顺序和充填体结构优化方案,优先进行关键区段采空区胶结充填,从而创造了稳定的开采环境。将分段崩落法和空场法逐步转换为安全环保的分段凿岩阶段充填、机械化盘区分层充填法等,实现了采空区治理与承压矿柱协同开采,从而取得了安全高效回收锡多金属资源的良好效果。

某齿轮坯精锻金属流动规律分析及工艺优化

提出了将终锻成形筋条的金属流动方式由径向流动为主转变为以轴向敦挤为主的方式。应用刚塑性有限元法对齿轮坯成形过程进行模拟,发现径向筋条充填不饱满是因为不合理的充填顺序。通过改变模具的结构,可有效改变筋条成形时金属的流动状态,以得到合理的充填顺序。模拟结果表明,筋条成形饱满。生产实践表明,锻件与模拟结果一致,其力学性能和尺寸精度等也符合要求。另外,材料利用率从48%提高到67.9%。

Sedimentary filling and sequence structure dominated by T-R cycles of the Nenjiang Formation in the Songliao Basin

The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyzed the drilling,well logging,core data,and seismic profiles of basin level,and by using the sequence stratigraphy,identified one secondary sequence boundary,two third-order sequence boundaries,and eight fourth-order sequence boundaries in the Nenjiang Formation.These eleven sequence boundaries can be divided into structural unconformity,depositional unconformity,flooding surface,and forced regression surface.Therefore the Nenjiang Formation can be subdivided into one secondary sequence,three third-order sequences,and ten fourth-order sequences.We have restored the sedimentary filling evolution within the stratigraphic framework of fourth-order sequences in the Nenjiang Formation.The sedimentary period of the first member of the Nenjiang Formation was corresponded to the global transgression period,which is also the development period of transgression cycle(T cycle),when the lake basin had the largest scope and deepest sedimentary water,the SB07(the maximum flooding surface)was formed on the top of strata during this period;covering above the SB07,there developed a set of condensation layer-oil shale,which is distributed in the whole basin and is the important source bed and regional cover.Therefore,a retrogradation sequence was formed in the T cycle of the first member of the Nenjiang Formation,characterized by the retrograding delta at a low angle.The delta has a giant front,a small plain,and many underwater distributary channels.Meanwhile,large gravity flow channels and sublacustrine fans are developed in the front of the delta.During the depositional period of the second member of the Nenjiang Formation,the R cycle began to develop due to the compression of the pacific tectonic domain;the source direction rotated 90°along with the eastern uplifting of the basin,and formed a series of east-west prograded and forced retrogradations.The prograding delta at high angel was developed in the interior of the sequence;the delta had a small front,a giant plain,and fewer underwater distributary channels,with the collapse at the foreslope,forming a series of slump fans.The slump fans can be divided into three types:discrete type,superimposed type,and fluid type.We built a whole"triad model"of the slump fan.Pointed out that the sequence of forced retrogradation formed by R cycle is a good structural mark of basin optimization,and rejected the viewpoint of"transgression"in the Nenjiang Formation of the Songliao Basin.