营口市滨海大道地质灾害危险性综合评估与防治措施

营口市滨海大道工程属于重要项目,建设用地所处地质环境为中等—复杂区,现状地质灾害主要类型为崩塌灾害。通过对危险性起决定作用的地形条件、地层岩性、构造地震、人类活动4方面因素的分析,该地区地质灾害危险性分级属危险性小级,地质灾害危险性分区属于危险性小区,因而在采取措施条件下适宜路桥建设,并提出了防治措施,为施工建设打下了基础。     

Groundwater recharge in an arid grassland as indicated by soil chloride profile and multiple tracers

Previous studies have shown that shallow groundwater in arid regions is often not in equilibrium with near‐surface boundary conditions due to human activities and climate change. This is especially the case where the unsaturated zone is thick and recharge rate is limited. Under this nonequilibrium condition, the unsaturated zone solute profile plays an important role in estimating recent diffuse recharge in arid environments. This paper combines evaluation of the thick unsaturated zone with the saturated zone to investigate the groundwater recharge of a grassland in the arid western Ordos Basin, NW China, using the soil chloride profiles and multiple tracers (²H, ¹⁸O, ¹³C, ¹⁴C, and water chemistry) of groundwater. Whereas conventional water balance and Darcy flux measurements usually involve large errors in recharge estimations for arid areas, chloride mass balance has been widely and generally successfully used. The results show that the present diffuse recharge beneath the grassland is 0.11–0.32 mm/year, based on the chloride mass balance of seven soil profiles. The chloride accumulation age is approximately 2,500 years at a depth of 13 m in the unsaturated zone. The average Cl content in soil moisture in the upper 13 m of the unsaturated zone ranges from 2,842 to 7,856 mg/L, whereas the shallow groundwater Cl content ranges from 95 to 351 mg/L. The corrected ¹⁴C age of shallow groundwater ranges from 4,327 to 29,708 years. Stable isotopes show that the shallow groundwater is unrelated to modern precipitation. The shallow groundwater was recharged during the cold and wet phases of the Late Pleistocene and Holocene humid phase based on palaeoclimate, and consequently, the groundwater resources are nonrenewable. Due to the limited recharge rate and thick unsaturated zone, the present shallow groundwater has not been in hydraulic equilibrium with near‐surface boundary conditions in the past 2,500 years.     

冻土切削力学特性的试验和理论分析

利用笔者所研制的冻土切削试验台，在室内对不同冻土在不同温度、含水量、切削速度、切削深度和切刀前角下进行了一系列切削试验。结果表明，切削时，冻土主要呈脆性断裂破坏，其切削过程被认为是刀刃切入和撕裂冻土的结果，切削阻力随冻土温度降低而非线性增加，随切削速度提高而略有增加，随切削深度增加而近似线性增加，最佳切刀前角随切削深度增大有增大趋势。但平均切削阻力与最大切削阻力之比值对不同试验条件基本在０．４－０．６５间变化。同时，根据切削过程机理，从理论上建立了最大切削力模型，此模型考虑了切入和撕裂冻土阻力。     

聚丙烯纤维复合土抗裂补强特性试验研究

将聚丙烯纤维按不同类型、不同组合、不同含量掺入土中的三轴压缩试验,研究了聚丙烯纤维复合土的应力-应变性状及对复合土强度特性的影响。试验结果表明,加固黏性土要选择分散性好的束状单丝聚丙烯纤维,而不是网状聚丙烯纤维,聚丙烯纤维按占土质量0.2%时为最佳掺入量,束状单丝聚丙烯纤维长度为6 mm+10 mm+15 mm+19 mm的4种组合较为理想,可使聚丙烯纤维复合土微结构联结强度得到明显改善,抗裂补强,黏性土抗剪强度得到极大的提高。     

某土石坝心墙料和坝基料动模量阻尼特性的试验研究

土石坝震害将导致严重后果,目前国内外修筑于地震区的土石坝在抗震设计时都进行了动力分析。室内动力试验提供土石料可靠的动强度和动力参数是土石坝地震动力分析准确性的关键。水牛家心墙土石坝坝高100多米,大坝设防烈度9度,采用动三轴仪,对其坝基②层细砂砾料和心墙防渗土料进行大量的动力特性试验研究,分析两种土料的动模量阻尼特性,并简述其影响因素。分析试验结果有：使用一个试样完成三个不同的围压力?3c或固结比Kc,与《土工试验规程》推荐方法相比,大大减小了试验和分析工作量, 且有相当的规律性和准确程度;动模量阻尼比的主要影响因素是动应变幅、围压力、固结主应力比、孔隙比等。动应变水平影响动模量阻尼成倍增减,动模量随围压力?3c增减而增减,阻尼比D随?3c的升高而略有减小,动模量和阻尼比随固结比Kc增减而增减,Kc从1到2可使心墙土料的Edmax增加60％左右;土类不同,模量阻尼也不尽相同。水牛家心墙料的动模量较高,阻尼比较小,不易产生动力破坏。     

地质时期生物与自然协调演化及化石燃料资源的分布规律

从更广泛和较高的层次对地质时期地球表层的生命活动和环境变化进行多学科的综合性研究，在全球系统分析的基础上为“协调人类与自然关系”的战略主题提供决策依据。以高分辨率地层学框架的研究的基础，综合多种学科对事件、间事件及其载体和介质的定量研究，为生物与环境的耦合机制的认识及有关模式的建立提供科学依据。化石燃料作为事件产物，其分布规律亦为重要研究内容之一。     

华北地台北缘花岗岩—绿岩型金矿田及盲矿体的找矿模型

花岗岩—绿岩型金矿田的找矿模型地质上是富镁铁质绿岩、韧性剪切带与重熔岩体的三体一位;物探上位于航磁高背景场的负磁异常带边缘,矿田晕分散流异常规模大、强度高,有明显的浓集中心。隐伏矿床、盲矿体的找矿模型地质上是韧性剪切带、退变质带及脆性断裂带的三体一位;物探上呈现高极化率、低电阻、位于磁异常边缘的“一高一低一边”模型;化探原生晕上呈现As、sb、F、Ag、Bi、W的找矿模型。     

Metallogenetic characteristics of an unique uranium-tungsten mineralization zone

A polymetallic zone dominated by U-W mineralization was found in Northeast Guangxi. Distributed along the east contact zone of a complex granite mass, it extends for about 100 km in length, with more than fifty deposits and prospects embraced. The deposits show a wide range of genetic types, related to the granite, from magmatic (including pegmatite and skarn deposits) through hydrothermal mineralizations (hypo-, meso- and epithermal) all the way to tin placers, constituting a very intact metallogenetic series of granites. The epithermal U-W deposits are considered as a new type for their unique geological and geochemical characters, such as the paragenesis of U and W and the large time gap (> 40 Ma) between ore and granite. This project was financially supported by the Open Lab. of Ore Deposit Geochemistry, Chinese Academy of Sciences.