灌注桩钻孔泥浆脱水机具的试验研究

采用卧螺离心机对灌注桩钻孔泥浆进行了脱水试验，简单介绍了卧螺离心机的工作原理和脱水过程，根据脱水效果与成本分析表明：卧螺离心机用于钻孔泥浆脱水具有良好的经济效益和社会效益。     

悬浮进样石墨炉原子吸收法测定纳米氧化锆粉体中的微量铝

采用水介质直接分散纳米氧化锆粉体悬浮进样，以水标准溶液绘制校正曲线，石墨炉原子吸收法测定其中的微量Al。系统研究了Al的原子化和灰化行为，不同分散介质及基体元素对测定Al的影响，获得了测定Al的优化条件。方法对Al的检测限为0．5ng／g，Al的线性范围为0～2．5mg／L，基体ZrO2的质量浓度小于2g／L时，对Al的测定无干扰，悬浮进样直接测定的RSD(n=5)为6．0％。样品的测定结果与其他方法对比基本一致。     

印尼某电站基桩的负摩阻力及其措施

基于印尼某电站场地的工程地质条件,根据基桩负摩阻力的产生机理,分析确定了中性点的位置,计算了负摩阻力产生的下拉荷载;并结合膨润土泥浆护壁的作用机理,计算了采取较大直径预钻孔和膨润土泥浆护壁的措施后负摩阻力产生的下拉荷载.计算结果表明,前者大于单桩承载力设计值,因此不能采用预应力混凝土管桩方案;后者较前者显著降低,约为单桩承载力设计值的50%,因此可以采用预应力混凝土管桩方案.     

钻孔灌注桩施工中的几个问题探讨：以上海华夏门广场工程为例

针对华夏门广场钻孔灌柱桩施工中有关循环用泥浆指标，围护桩施工方法等展开讨论结合工程实践提出了关于泥浆指标变动范围，围护桩施工的跳打方式等观点。     

Parameter studies on the rheology of limestone slurries

The influences of solids concentration, molecular weight of dispersant, particle size and distribution, and temperature on the rheological behaviour of limestone slurries have been investigated. The results reveal that when the solids concentration of a limestone slurry (< 100 μm) is increased from 60 wt.% (35.71 vol.%) to 78.5 wt.% (57.49 vol.%), the rheological behaviour of the slurry is transformed from a weakly dilatant characteristic to a pseudoplastic one with a yield stress, which is in combination with a thixotropic property at a higher solids concentration (i.e., ≥ 75 wt.% or 52.63 vol.%). At a certain shear rate, the apparent viscosity and the relative viscosity of the slurry increase exponentially with solids concentration. The extrapolated Bingham yield stress increases rather sharply in a power-law form with increasing solids concentration when the solids concentration of the slurry is larger than 70 wt.% (i.e., 46.36 vol.%). An attainable maximum packing solids fraction (?_m) is predicted as ?_m = 64.6 vol.% at the certain limestone–water suspension system. A polymeric dispersant named Dispersant S40 with a molecular weight of 5500 appears most effective for the reduction of the apparent viscosity of limestone slurry due to its good electrosteric stabilization and effective avoidance of depletion flocculation. The smaller the particle size and the narrower the size distribution, the more evident the pseudoplastic property of limestone slurry is with a larger yield stress and a larger apparent viscosity at a given shear rate in the range of 12 to 1200 s^− 1. Also, a statistic model describes a relationship between the particle size and distribution and the apparent viscosity of the slurries at a given solids concentration (i.e., 70 wt.% or 46.36 vol.%). However, a sufficient additive dosage of Dispersant S40 (i.e., ≥ 0.1 wt.%) significantly decreases or even eliminates the rheological differences of limestone slurries (apparent viscosities and extrapolated yield stresses) resulting from the difference in particle size and distribution. Besides, the apparent viscosity of limestone slurries decreases with increasing temperature in the range of 13 to 55 °C, regardless of the absence or the presence of Dispersant S40.     

城市垃圾填埋场水泥基防渗浆材的研究

针对垃圾填埋场防治沥出液渗漏的要求，研制了一种水泥基膨润土-粉煤灰-水泥（BFS）防渗浆材，该浆材具有渗透系数低、吸附阻滞性能好的特点。介绍了该浆材的材料及试验研究成果。     

牛儿庄矿奥灰特大溃水灾害的治理研究

2004年9月25日牛儿庄矿发生了突水量达108m^3／min的特大溃水事故，直接威胁了相邻两个矿井的安全生产。通过调查分析认为此次突水水源为煤系基底奥陶系灰岩含水层，是他于牛儿庄矿井田范围内的水顺煤矿开采下架煤层突水而造成的。在突水通道、动水力等条件复杂的情况下，经过三个阶段的水害治理，效果达100％．为类似堵水治理工程提供了有益的借鉴．     

钻（冲）孔灌注桩灌注质量的控制

钻（冲）孔灌注桩在灌注施工及成桩后常见的事故有堵管、卡管、埋管、桩身蜂窝、夹泥、混浆、露筋甚至断桩，通过对常见事故的分析找出其产生的根本原因，在灌注施工巾针对产生事故环节严格控制，从而避免事故发生。     

A new fractal modification of ultrasonic attenuation model for measuring particle size in mineral slurries

Weight percentages of different size incremental particles in a mineral slurry is integrated into the ultrasonic attenuation model to derive a relation between ultrasonic attenuation and particle sizes. However, in the inertial and scattering regimes of frequency–radius space, irregularity and aggregation of particles can results in values of ultrasonic attenuation that are significantly different from those predicted by the derived model, which is based on the assumption of separated smooth spherical particles in mineral slurries. Experimental attenuation data obtained previously from mineral slurries of iron ores particles are compared with predicted values. It is shown that there is a negligible difference between predictions and experimental data. A new modification of theoretical model for ultrasonic attenuation is derived. The theory uses ωτ_v or κR as a fractal scale. It requires an empirical determination of the difference between the fractal dimension of the measured mineral slurry and that of a hypothetical slurry of spheres with the same particle size distribution. The new fractal modification of ultrasonic attenuation model is found to enable better agreement with measured attenuation as a function concentration for irregular particles than the theoretical model. Moreover, the fractal approach is found to discriminate between the effects of particle irregularity and aggregation.     

水泥-粘土浆液护壁堵漏工艺研究及其工程应用

钻探工程中钻孔漏失常用纯水泥浆液进行堵漏,而针对矿区复杂地层钻进,漏失严重,易垮孔卡钻,为防止漏失及井内事故发生,必须使用高效的水泥堵漏浆液及合理的堵漏工艺。以道真新民铝土矿区为例,对水泥-粘土浆液护壁堵漏工艺进行研究,分析了水泥浆液中加入膨润土、水玻璃、减水剂后性能的变化规律,得出水泥堵漏浆液的优化配方。实际工程应用中取得了良好效果,大大提高了钻进效率。