为揭示黏性土中表面活性剂与有机污染物的相互作用特征,文章选用N-月桂酰肌氨酸钠(sodium lauroylsarcosinate,SLS)为表面活性剂、甲基叔丁基醚(methyl tert-butyl ether,MTBE)为有机污染物,系统研究表面活性剂对黏性土中有机污染物的增溶、解吸作用.试验结果表明:表面活性剂对MTBE的增溶作用随其质量浓度增加而快速增大并趋于稳定;黏性土对污染物的吸附作用显著,可使用Henry模型获取其吸附特性及分配系数;表面活性剂质量浓度较低时,土体对污染物吸附作用较强,当增至1300 m g/L后,表面活性剂将促进污染物解吸;低质量浓度表面活性剂并未显著影响土体整体污染程度,但显著的增溶作用将促进污染物迁移,使其分布更趋均匀;高质量浓度表面活性剂对污染物的显著解吸作用将增加土体中溶解态MTBE质量浓度.研究结果可为有机污染物场地修复研究提供参考.

酸雨可与MICP矿化作用过程中生成的碳酸盐反应,破坏材料的结构强度,使被固定的重金属离子再次释放,但该技术在酸雨环境下的研究较少,耐酸腐蚀性尚不明确,因此对酸雨入渗作用下MICP固化重金属污染土的淋滤特性的研究具有现实意义.本文设计了pH值为3.5、4.5、5.6的3种典型的酸雨条件,用pH值为7.5的去离子水作对照,通过土柱淋滤的方法对MICP固化粉土进行了实验研究,分析不同酸雨pH值对MICP固化铅污染土样的强度、pH值、Pb2+、Ca2+淋出量及Pb2+赋存形态的影响.结果表明:随酸液pH值降低,MICP固化试样的强度降低,淋出液pH值降低,Pb2+、Ca2+淋出量增加,固化试样中可交换态的Pb2+增加,当pH值为5.6时,试样受酸雨影响较小,pH值降为3.5时,试样变化显著.

为研究全体外预应力节段拼装梁的极限应力和抗弯承载力,提出了基于全体外预应力节段拼装梁变形和预应力增量相协调原理的计算方法.该方法将体外预应力增量分为梁体线弹性未开裂阶段和开裂后阶段两部分,分别推导出两阶段预应力增量,考虑预应力二次效应,建立以梁体转角θ为参数的全体外预应力节段拼装梁极限应力和桥梁抗弯承载力计算公式.为验证公式的准确性,以芜湖长江公路二桥引桥40 m全体外预应力节段拼装梁为背景,开展足尺模型试验,并与国外学者的试验数据进行对比.结果表明:所提出的公式计算值与试验实测值误差较小,该公式可准确计算全体外预应力节段拼装梁的极限应力;为简化计算,在工程设计时转角 θ可取0.0176°,转角θ取值与国外学者的试验数据具有较好的一致性;根据极限应力增量推导的抗弯承载力计算公式可预估桥梁抗弯承载力,指导工程设计.

为获取增稠剂、表面活性剂注入位置对曝气影响范围、污染物时空分布及去除率演化特征的影响,文章开展了二维模型箱曝气试验.研究结果表明:曝气修复过程中掺入增稠剂将显著影响曝气影响范围,而掺入表面活性剂后的影响相对不显著;利用增稠剂限制曝气影响范围后将大幅增加土体有效气相饱和度,表面活性剂的掺入将进一步提升有效气相饱和度水平;增稠剂能显著改变污染物迁移路径,增强总去除率,在此基础上,表面活性剂将进一步强化优势迁移路径上的污染物通量,提升污染场地修复效率.

To analyze the influences of parameter uncertainty on system reliability, a system reliability sensitivity analysis method based on the sequential compounding method (SCMSA) is proposed. The SCMSA makes use of the principle of SCM combination element, and further calculates the equivalent correlation coefficient between the two components and other remaining components in the system on the basis of calculating the reliability and sensitivity of a simple system with two components in parallel or in series, so as to achieve the purpose of combining the two components and simplifying the complex system. The advantage of SCMSA is that it integrates the calculation of the relative sensitivity index into the system reliability analysis, so that the sensitivity analysis can be calculated together as a byproduct of the reliability analysis, and this method can be applied to the system reliability sensitivity analysis of the relative non-normal variables. Finally, a simple numerical example is used to illustrate the calculation process, calculation accuracy and calculation advantage of SCMSA, and it is applied to the sensitivity analysis of a system reliability of semi-gravity retaining wall, indicating that the SCMSA can provide a theoretical basis for the risk analysis and prevention of geotechnical engineering.

土石混合体的物质组成比较特殊,其本质是由土颗粒与石块组成,是一种特殊的工程地质体,但在工程中经常将土石混合体及其边坡作为均质材料处理,利用MIDAS软件对土石混合边坡进行数值模拟计算,分析研究不同块石粒径、不同降雨强度对土石混合边坡稳定性产生的影响.研究结果表明,当含石量相同时,边坡的稳定性不会随着土石混合体中的块石粒径而改变,但边坡的位移范围会随着块石粒径的增大而减小,边坡的滑动带形状也会发生改变.边坡的稳定性随着降雨强度的增加而相应的改变,随着降雨强度的增加边坡安全系数逐渐降低,且位移范围也随之增加.

Expansive soils are widely distributed in China, especially in the regions with high population density. Characterized by the well-known 'three properties', i.e., swelling-shrinkage, cracking and over-consolidation, the expansive soils are highly susceptible to climate change and engineering activities, and thus can easily cause landslides. Due to the lack of consideration to the interactive 'three properties' of the expansive soils, the traditional techniques can hardly be effective for the treatment of expansive soil landslides and engineering slopes, leaving the latter known as 'cancer' that imperils the safety of engineering projects. During the 13th Five-Year Plan period, the National Key Research and Development Program of China "New prevention and treatment techniques and their applications to landslides and engineering slopes of expansive soils" was approved. With special attention to the interactive 'three properties' of the expansive soils, the program has made series of innovations including the instability mechanism and the key disaster factors of expansive soil landslides, multi-field information monitoring and early warning techniques, 'surface-shallow-deep' integrated and ecological reinforcement technique, health diagnosis and rapid restoration techniques for slope protection structures. These techniques are integrated as a technical system and have been implemented in three engineering demonstrations. The relevant achievements have provided new theories, techniques and construction methods for treating the landslides and engineering slopes of the expansive soils. Meanwhile, they have achieved significant social, economic and environmental benefits, with broad application prospects.

为满足社会经济发展需求,新时代地质工程专业硕士研究生培养模式改革势在必行.文章针对高校专业硕士的培养模式所存在的弊端,提出由学生、学校、行业(企业)之间有机联动的"产学研"培养模式.以培养实践能力为出发点,"产学研"为衔接手段,校内实验中心和实践基地与校外实践基地为载体,根据地质工程专业的特色,构成独特的地质工程专业硕士课程体系和实践教学模式.

The soil-water characteristic curve (SWCC) is an important curve describing the relationship between the suction of unsaturated soils and the saturation or water content, and is an important basis for analyzing the strength, deformation and seepage of unsaturated soils. It is very time-consuming to measure soil suction directly or indirectly indoors. In order to quickly and accurately obtain the SWCC of unsaturated soils, an improved method for predicting SWCC based on the pore size distribution (PSD) of soils is proposed. This method uses the mercury intrusion porosimetry (MIP) to measure the PSD of soils, and the filter paper method is used to measure a suction value of soil samples and its corresponding saturation. Then according to the test results at this point, the pore volume of soils measured by the MIP tests is corrected, and the pore volume after correction is used to calculate the saturation of soils under different suction conditions. This method can overcome the problem of small pore volume measured by the MIP tests. The comparative analysis of the predicted and measured SWCCs before and after the correction of 9 groups of soil samples shows that the proposed method can predict the SWCC of unsaturated soils more accurately. On this basis, the fitting parameters of SWCC and their probability statistical characteristics of multiple groups of soils can be obtained conveniently and quickly.

铜陵市朝山地区岩溶塌陷灾害是安徽省大型地质灾害隐患点.从该区基岩岩性、覆盖层特征、水文地质条件和人为影响等方面入手,利用钻探和地下水长期观测等技术手段,通过岩溶塌陷的影响因素分析,查明了研究区岩溶塌陷形成条件,评价了地面稳定性.得到主要结论如下:区内岩溶塌陷的分布受断裂控制,90％以上的塌坑位于距断裂20 m区域内;区内岩溶塌陷的发生与基岩岩性密切相关,CaO含量高有利于塌陷的发生;区内塌陷多发生于多元或二元结构地层区域;矿山排水是区内岩溶塌陷的主要诱发因素.最后在查明区内岩溶塌陷形成条件的基础上,采用经验指标法对朝山地区地面稳定性进行评价分析,确定研究区为易塌陷区,须重点监测与防治.

地下空间具有封闭性和较强的不可逆性等特点,因此在开发前需要以量化的指标加以评估.文章根据模糊层次分析法,以社会经济条件评估城市地下空间开发必要性,以区域条件评估城市地下空间开发适宜性,旨在提出一套能适用于大部分城市的地下空间评估指标体系.指标体系着重考虑了工程地质条件对适宜性的影响,之后对南通市地下空间开发必要性和适宜性做出了评估.结果显示:南通市开发地下空间非常有必要,开发潜力十分巨大,大部分区为较适宜开发区.

碱渣是一种工业废弃物,与水泥一样可用来加固软土地基,配制不同比例的水泥碱渣对软土进行加固,养护28 d进行无侧限抗压强度以及压缩特性的试验,通过试验可得,水泥和碱渣可以明显提高无侧限抗压强度和降低土体的压缩性,并且选出最优配比应用于工程实践.通过微观试验分析,水泥碱渣加固后的土体产生了具有胶凝性的CAH,CSH以及钙矾石,对于强度的增加和压缩特性的变化做出了微观解释.

Most of researches related to the immobilization mechanisms of stabilized/solidified heavy metal contaminated soils were depended on the mechanical tests and chemical analysis. Thus, proposing a physical method that is un-destructive, time-saving, convenient and cost-effective is the urgent issue to be solved currently. In this paper, a series of laboratory tests including electrical resistivity test was performed to investigate the microstructural mechanism of cement-fly ash stabilized heavy metal contaminated soils. Furthermore, the prediction model of unconfined compressive strength was established based on the electrical resistivity. The tests results presented that with increasing of curing time, electrical resistivity, pore water electrical resistivity, structure factor, as well as shape factor of the specimens increased, and the anisotropy coefficient decreased. While increasing the heavy metal ions concentration leaded to an obvious reduction in electrical resistivity, pore water electrical resistivity and shape factor, and the anisotropy coefficient increased gradually. The SEM results was consistent with that of the electrical resistivity, which confirmed the feasibility that revealing the microstructural mechanism of the stabilization/solidification of heavy metal contaminated soils by electrical resistivity method. Finally, a good linear relationship between the electrical resistivity and unconfined compressive strength can be obtained. It is suggested that the electrical resistivity can be used as the index to evaluate the mechanical properties of the stabilized soil.

中国每年产出大量钢材,伴随而产生的副产品钢渣,因其利用率低而导致资源浪费和环境污染.为充分、高效地再生利用废弃钢渣,从提升钢渣的胶凝性出发,参考水泥组分的率值控制指标,采用偏高岭土对钢渣进行成分增补,以提高Al2O3和SiO2含量,开展水玻璃的硅系激发及水泥的复合系激发试验,制备得到钢渣型复合基材.净浆一定龄期后进行无侧限抗压强度试验,并尝试引入率值这一参数评价钢渣基材性能.结果表明:当水泥、偏高岭土和钢渣之间最优质量配比为50∶15∶85,水胶比为0.28时,复合基材的90 d强度可达41.5 MPa.复合系与钙系钢渣型基材的率值高度一致,可为不同初始成分的钢渣基材的标准化制备提供参考.采用XRD,SEM,MIP等多种微观测试技术探讨钢渣基材强度形成机理,发现钢渣基材水化产物为C-H,C-(A)-S-H和C-A-H等,其中网状C-S-H最为发育,各部分紧密联结,大孔隙减少,使得钢渣复合基材强度保持稳定增长.将钢渣基材用于软土加固中,当钢渣基材掺量为20％时,固化软土28 d龄期无侧限抗压强度可达1.2 MPa.固化土强度与似水灰比R成反比,给出了可用于预测钢渣基材固化土强度预测的经验表达式.

On the basis of three issues,namely,the recycling of industrial waste slag,the application of high-performance geopolymer in modified compaction soil and performance improvement of cement-based modified compaction soil,a series of tests in laboratory were conducted on cement-based modified compaction soil with additive steel slag and metakaolin.The macro behavior of cement-based modified compaction soil was discussed in detail from compaction properties,compressive strength as well as splitting tensile strength.Thereafter,the microstructure tests (including SEM,XRD,TGA and MIP) were adopted to clarify the internal mechanism (including hydration product,microstructure and pore size distribution) to provide the theoretical basis for the recycling of waste and performance improvement of cement-based modified compaction soil.The results of macrostructure tests show that the steel slag can improve the compaction characteristics and mechanical strength of the cement-based modified soil,whilst the metakaolin can significantly improve the above performance.It is worth noting that with the additive of metakaolin,the strength increases and then decreases,and the optimal ratio between metakaolin and cement is in the range of 1/3 to 1/2.Furthermore,the splitting tensile strength is proportional to unconfined compressive strength,with the ratio of 0.83.The results of microstructure tests show that the additive of steel slag and metakaolin cannot change the types of hydration products of the cement-based modified compaction soil,but change the parcel formation and the number of hydration gelling.Hence,the microstructure and porosity distribution are altered.In a word,the steel slag and metakaolin improve the behavior of cementbased modified compaction soil with different quality.

实验教学是高等学校教学工作的重要组成部分,是沟通理论与实践的桥梁.为了提高实验教学质量,培养具有较高科研素质、较强创新精神和实践能力的创新型拔尖人才,提出了土工实验教学改革的两个具体办法:要求学生进行研究性预习,提交实验所需的电子表格;对实验过程进行数值模拟分析,深入理解实验过程及影响因素.通过教学改革,可以提高学生的预习效果,提高实验课教学质量;可以更好地将理论与实践相结合,促进学生对实验过程、现象及影响因素的深入理解,学会深入分析问题.这种改革有利于培养具有扎实理论基础、较强工程实践能力及创新能力的高素质人才.

培养富有较强的科研精神、创新意识及实践能力的人才是新时期高等教育教学改革的核心目标之一.文章以勘查技术与工程专业为例,探讨建立课内与课外相结合的三层次研究性创新实践教学体系、研究性创新实验教学与实习教学的具体内容与方法,旨在通过研究性创新实践教学,充分调动学生进行创新实践学习的积极性,使学生具有良好的科研素质、创新意识及较强的动手能力.

Toxicity characteristic leaching procedure ( TCLP ) was conducted in the artificial pre-pared Pb-contaminated soils treated by soda residue to assess the effectiveness of stabilization/solidi-fication. By analyzing the effects of the initial Pb2+ concentration, soda residue content and curing time on the leached Pb2+ mass concentration and pH value of the leachate,the leaching properties of Pb2+ immobilization were discussed. The test results indicate that the leached Pb2+ mass concentration increases with the increase of initial Pb2+ concentration of the soils. And increasing the soda residue content and curing time can effectively reduce the leached Pb2+ mass concentration. Otherwise, the variations of pH values of the leached solutions are mainly controlled by soda residue content and cu-ring time.

压力型锚杆的应变分布情况反映锚杆损伤破坏位置,利用3次实验室小比例尺模型进行拉拔试验,可以对锚杆的应变分布等进行研究,取得合理的结果.(1)对各级拉拔荷载作用下的锚杆顶部位移进行记录分析,得到了拉力顶部位移与拉力关系图,其曲线的形态说明拉力达到一定程度将引起位移的迅速增加;(2)对锚杆各部位直径增加量做了分析,发现在离承压板锚杆一定位置处直径增加量最大;(3)对锚杆的轴向应变、径向应变的数值和分布情况进行了对比,发现轴向应变是锚杆应变的主要形式,但轴向应变、径向应变分布规律基本一致,都随远离承压位置呈负指数衰减.因此,在提高锚杆的锚固效果方面,减小锚杆承压板附近的形变是一个有效的途径.

The leaching behavior of the cement - stabilized heavy metal contaminated soils was changed in the aggressive environment ( contained sulfate,chloride and so on) . Therefore,a leaching test was conducted in the cement-stabilized Pb-contaminated soils immersed in the NaCl solutions to investigate the chemical durability. The results reveal that the leachate pH values decrease with the in-crease of NaCl concentrations,as well as the Pb2+ mass concentrations in the leachate decrease. The pH values reach the lowest level,while the Pb2+ mass concentrations reach the maximum value dur-ing a short-term immersion. Thereafter,the leachate pH values increase and the Pb2+ mass concentra-tions decrease with the increase of soaking time. When the Pb2+ contents are lower than 5 000 mg/kg,the leached Pb2+ mass concentrations are all lower than 5 mg/L,satisfying with the environ-mental safety limit. While the Pb2+ contents are up to 10 000 mg/kg,the leached Pb2+ mass concen-trations are generally more than 5 mg/L,thus it is not satisfied with the environmental safety limit.