Stochastic structural model of rock and soil aggregates by continuum-based discrete element method

Ancient slope[1], debris-flow deposit[2] and rock-filling dam[3] are usually made of rock and soil aggregates (RSA). The RSA is a typical inhomogeneous and discontinuous medium, and its main characteristics include: (i) loose piling up by blocks or particles, (ii) mixing of different blocks with a range of shapes and sizes, (iii) stochastic distribu- tion of blocks in space, (4) fillings often in between blocks. The mechanical properties of these rock and soil aggregates are commonly obtaine…     

水下长隧道最小安全顶板厚度研究

根据轴线地质剖面和隧道轴线布置图,对某拟建中水下公路隧道最小安全顶板厚度的确定进行了研究,通过比较得出最合理的最小安全顶板厚度,对同类工程有很大的参考价值。     

云南禄丰鸡街碱性超基性岩杂岩体的成因

在研究鸡街碱性超基性岩杂岩体岩石学和地球化学已有资料基础上，认为本区霞霓钠辉岩平均成分加１０％，Ｆ０＝８６的橄榄石可作为杂岩体的原始岩浆，Ｐ２Ｏ５估算出这种岩浆为地幔岩经约３％部分熔融的产物；岩石学混合模拟计算表明，地幔源岩具有明显亏损特征；原始霞霓钠辉岩岩浆经约２９．６％结晶分异形成霓霞岩，霓霞岩岩浆再经约４７．２％结晶分异形成磷霞岩。由此建立起杂岩体的成因模式。     

面板堆石坝下游坝坡稳定可靠度分析

应用考虑条块间水平作用力的条分法，在非线性破坏准则的基础上，结合堆石面板坝的破坏模式，构造了完整的面板堆石坝下游坝坡稳定可靠度分析模型，并结合实例进行了计算．所得结果合理，表明该模型比较符合实际．     

超短半径水平井开采煤层气的探讨

超短半径径向钻井系统可以在0 3m半径的立井井段中,完成从垂直转向水平,保证水平井准确进入目的层,并采用高压水射流破岩形成水平井眼,解决了常规钻水平井技术所遇到的施加钻压困难和钻杆旋转所带来的一系列问题,减少了井下事故的发生并提高了钻井速度.本文通过对超短半径径向钻井系统的基本原理和施工方法的详细介绍,试图把超短半径径向钻井系统这项先进技术作为一个新的技术手段引入煤层气开采中来,以提高煤层气的采出率.     

新城金矿床围岩蚀变与金矿化的关系

本文就新城金矿围岩蚀变的特征、与金矿化的关系、金与多金属硫化物的关系、依变岩石中金的富集规律进行了探讨,指出了围岩蚀变是重要的成矿地质条件．     

Consideration on Effective Diffusivity of Strontium in Granite

Abstract

Diffusive behavior of strontium and certain kinds of divalent cations in Inada granite were studied by a through-diffusion method. In order to examine the effect of sorption onto overall diffusive behavior, two kinds of solutions were used: 0.1M KCl solution and deionized water. The effective diffusion coefficient (D_e ) and rock capacity factor (a) were (2.0–3.6) xl0–¹³ m²/s and less than 0.022 in 0.1M KCl solution and (0.32–1.7) x 10 ^?13m²/s and 1.5–2.4 in deionized water respectively. The D_e , and α in deionized water were much larger than those in 0.1M KCl solution. These results are well explained by taking into account the diffusion of sorbed ion or the surface diffusion. In support of this mechanism, most D_e , values of Sr reported for various rocks are found proportional to the sorptivity ( _ρR_d )-In the case that the sorptivity is low, D_e of Sr depends on porosity like that of nonsorbed iodide. The effective diffusion coefficient of Sr in rocks was well explained by taking into account pore and surface diffusion and was expressed as D_e=2.1 xl0^?10 _? ^1.3+3.5xl0″^?12 _ρR_d . The effective diffusion coefficient of divalent cations in the granite was found proportional to their diffusion coefficients in bulk solution.     

ADS熔盐散裂靶中子学性能研究

与传统加速器驱动次临界系统（ADS）采用金属靶作为散裂中子靶的设计不同,加速器驱动次临界熔盐堆（AD-MSRs）采用靶堆一体的设计,直接使用燃料熔盐作为散裂中子靶。由于熔盐靶的中子学性能直接影响AD MSRs的能量放大系数、核废物的嬗变和核燃料增殖的效率,所以本研究基于MCNPX程序,详细计算了高能质子轰击氟盐和氯盐两种熔盐靶产生的散裂中子产额、散裂中子能谱、能量沉积分布以及散裂产物等中子学性能,并与液态Pb和铅铋共熔体（LBE）两种液态金属靶进行了对比。计算结果表明,熔盐靶在散裂中子产额上与液态金属靶有一定的差距,但熔盐靶内能量沉积分布的梯度较小,更有利于靶区的热量导出。与液态Pb和LBE靶相比,熔盐靶的散裂产物中包含更多的气体以及高质量数的α发射体核素。     

条形药包爆破破岩规律的试验研究

分析了前人关于爆破破岩机理论述方面的矛盾，通过高速摄影观察有机玻璃中条形袋药爆炸波和破裂缝发展规律，得到了关于条形药包爆破破岩规律方面的新认识。提出了冲击该、气体膨胀压和反射拉伸波在破岩过程中各自所起的不同作用。特别在此基础上推出了条形药包下破裂深度计算公式，对工程实践有积极的指导作用。     

The improved neutral network and its application for valuing rock mass mechanical parameter

The artificial neutral network（ANN） has the ability that self-study and self-remember, its 3 layers BP network has been applied extensively, but sometimes because of serious multi-correlation between the variables, and a few observations while many variables, there usually will result into paralyzing in study, and the neutral network further development is restricted in the system to some extent. The partial least square regression（PLS） has its advantage of building the calculation model between the variables with strong multi-correlation, especially much effective on a few data and many variables. So a new and effective method-improved neutral network has been introduced-the neutral network based on the PLS. The results of example show the improved method has a few calculations and high accuracy, and provide a new way for valuing the rock mass mechanical parameters.