Clast exposure on boulder-covered desert slopes

Variation in the degree of clast exposure on stony desert slopes is examined in an area of northeast Jordan. Geological influences on the characteristics of stone mantles are modified by relative slope position. Observations that the nature of the surface stone cover changes downslope because of the transport and accumulation of the underlying substrate are confirmed by quantitative analysis. An elliptic function is described as a means of estimating relative clast exposure from simple field measurements of clast dimensions. There are no significant differences in mean clast exposure between the four main basalt lithologies of the study area, but a distinctive pattern of clast exposure catenas can be identified. Convex slopes maintain relatively high levels of clast exposure from crest to toe. About two-thirds of the variation in clast exposure is accounted for by lithology and four slope variables: relative relief, slope length, gradient and curvature. Copyright © 1999 John Wiley & Sons, Ltd.     

陕西省观赏石资源的分类

陕西省观赏石资源分为单矿物玉石类、岩石玉类、卵石与水冲石及古生物化石四大类。著名的观赏石有水晶、萤石、绿松石、五彩石、芙蓉石、商洛翠玉、粉翠、菊花石、蓝田玉、洛南翠、黄陵石、磬玉石、墨玉、汉江石、秦岭石、泾河石、洛河源头石、陕西省黄河石、嘉陵江石及古生物化石等。     

菊花石形貌测量及生长机理探讨

对华南栖霞组中菊花石花瓣单晶及花体总貌（即矿物集合体形貌）中的各细节进行了测量与统计,确定了菊花石各中花瓣的结晶取向关系及花体总貌中的某些特征参数,探讨了菊花石的生长机理并用其解释菊花石的形貌特征及结晶环境。     

贵州思南乌江喀斯特国家地质公园旅游环境容量研究——以石林主景区为例

在研究总结国内外研究现状的基础上,应用线状总量模型和面状总量模型从空间环境容量、生态环境容量、经济环境容量、心理环境容量四个方面综合研究了贵州思南乌江喀斯特国家地质公园石林主景区环境容量,最后根据“木桶原理”确定石林景区合理的日环境容量旺季为7298人,淡季为3649人,年环境容量为182.45万人,在此基础上提出了从旅游路线、就餐处特色、管理方式三方面采取合理调节人车分流比例、交通线路适时分流、游客自主分流就餐三项调控措施,以期实现景区游人合理分布、基础设施充分利用。      

四川石材资源及其开发建议

四川是一个石材大省。本文依据详尽的经济地质资料介绍了四川主要高档优质石材。四川产出的优质石材,包括红色系列、黑色系列、蓝绿色系列的花岗石;白色系列、黑色系列的高档大理石,在国内外拥有广大的潜在市场。鉴于此,提出了关于四川石材开发利用的有益建议。     

Strengthening crushed coarse aggregates using bio-grouting

This paper focuses on using urea hydrolysis as a bio-grouting process to increase the strength of crushed aggregates commonly used in stone columns. Various reagent phases (2, 4, 6 and 12 phases) consisted of alternately percolating solutions containing bacterial suspension and cementation solution through the soil column. In addition, a multi-soil lift strategy with options of up to four soil lifts was undertaken to test the applicability of bio-grout to cement crushed aggregate columns. While the average amount of calcium carbonate precipitation was roughly unchanged in both techniques, the distribution within the crushed aggregate columns was heterogeneous. However, the distribution of the precipitated calcium carbonate is almost uniform in crushed aggregates treated by a two-soil lift strategy and a four-phase treatment strategy. It is also deducted that both techniques can be combined to gain a uniform calcium carbonate and strength along a long sand/stone column. Furthermore, a one-soil lift resulted in higher strength than using multi-soil lifts, and a maximum strength of approximately 2.3 MPa was achieved using 4-reagent phase treatment strategy. Scanning electron microscopy and electron dispersive spectroscopy analysis validate that calcium carbonate was deposited as white crystals on the surface of the crushed aggregate particles.     

基于混合离散的砌石挡土墙边坡极限承载力下限分析

将极限分析下限法理论、混合数值离散思想和线性规划结合起来研究砌石挡土墙边坡的极限承载力。采用三角形有限单元离散土体来模拟土体的连续介质力学特性,构建土体静力许可应力场的约束条件,采用块体单元离散砌石体来模拟砌石体的非连续介质力学特性,构建砌石挡土墙的静力许可应力场的约束条件;同时建立有限元单元和块体单元交界面的约束条件;然后以超载系数为目标函数建立求解砌石挡土墙极限承载力的下限法线性规划模型,并使用内点算法进行最优化求解,获得边坡的极限荷载（或安全系数）和对应的应力场。通过3个算例的分析验证了所提方法的正确性。所提方法是将混合数值离散思想引入极限分析领域的一次尝试。     

深圳市扩库填海问题研究

填海造地对深圳市具有深远的可持续发展意义,而增加调蓄水库库容不仅具有现实的经济意义,而且具有巨大的环境和生态意义,扩库填海是满足此两个意义的最优选择。分别从生态、环境、景观、经济、社会、城市供水安全等角度论证了扩库填海的必要性和合理性。     

一种振冲碎石桩复合地基的沉降计算方法

对振冲碎石桩复合地基桩体和桩间土的变形与应力--应变关系进行研究。假设在荷载作用下,复合地基中桩体变形均匀,桩－土变形协调,推导出振冲碎石桩复合地基沉降计算公式为: ABk2 εh3v + 2ABhkεh2v + A ( D2 + B) h2hv = nh2 pD2 ; 利用牛顿迭代法解一元三次方程,可求得复合地基沉降。将本方法应用于沿海某大型储油罐工程,计算振冲碎石桩复合地基总沉降量为171. 5 mm,实测沉降量为 162. 2 mm,计算结果与实测结果基本吻合,表明该方法有一定的实用性。     

草酸钙生物矿化膜的形成机理和化学仿制－－一种新型石质文物表面防护材料的开发研究

已经发现一些年代久远的含钙岩石表面有一层天然生成的矿化膜，矿化膜保护下的石刻文字可以历经上千年的风雨而保持完好。本工作探讨了这种膜的组成和来源。膜的样品用FTIR、PLM、EDAX、SEM和TEM进行了分析。检测发现天然矿化膜的主要成分为草酸钙，许多证据表明这是一种生物矿化膜。本文讨论了膜的形成机理。为了开发新型石质文物表面防护材料，我们在实验室中用化学仿制的方法在含钙岩石上生成了这种保护膜，同时研究了膜的生成条件与保护效果之间的关系。