大口径牙轮钻头设计存在的问题及其改进方法

硬岩中钻进是基桩孔钻进中的一大难题，不少工地试图用牙轮钻头钻进基岩，但一直未取得理想的效果，大口径牙轮钻头在硬岩中钻速低，磨损快。不少研究者指出，其原因主要是由钻压过低而又无法加压所致，便在现场，一些用石油钻牙轮装配的钻头，不加压也难以转动，因而根本无法增加钻。本文从运动学方面分析了钻头所存在的这一问题，提出了纯滚动牙轮钻头的设计方法，并考虑了如何使钻头上内外周牙轮等磨损以提高钻头寿命的问题。     

牙轮钻头直径的计算

采用求极值来计算牙轮钻头的直径，给出了牙轮钻头直径的计算公式，并分别对有移轴及无移轴牙轮钻头直径的计算进行了分析。     

KZ型CCSD专用扩孔钻头的研制

介绍了KZ型CCSD专用扩孔钻头的技术特点、技术指标、钻进工艺参数的确定原则以及钻头生产中的有关事项，并简要介绍了钻头实钻检验的有关情况。     

对组合牙轮钻头和滚刀钻头的一些认识与体会

根据实践经验，分析了PZ系列组合牙轮钻头和CG系列滚刀钻头的结构特点，并就钻头使用中的钻头选型、钻进参数、泥浆循环以及注意事项等谈了一些认识和体会。     

PZ系列拼装组合式大直径牙轮钻头的研制与应用

ＰＺ系列拼装组合式大直径牙轮钻头可适用于嵌岩灌注桩钻孔和水井的钻进。该系列钻头直径从４００ｍｍ到２０００ｍｍ，本文对钻头的外形设计、底面结构形式、牙轮的选择和分布以及水力学设计等进行了阐述，该型钻头经１００多个单位使用，效果良好，作者也提出了改进方向。     

大口径牙轮钻头设计中存在的问题及其改进方法

硬岩中钻进是基桩孔钻进中的一大难题．不少工地试图用牙轮钻头钻进基岩，但一直未取得理想的效果。大口径牙轮钻头在硬岩中钻整低，磨损快．不少研究者指出，其原因主要是钻压过低而又无法加压所致．但在现场，一些用石油钻牙轮装配的钻头，不加压时难以转动，因而无法增加钻压．本文从运动学方面分析了钻头所存在的这一问题．提出了纯滚动牙轮钻头的设计方法．并考虑了如何使钻头上内外周牙轮等磨损以提高钻头寿命的问题。     

DKY95XHP5型钻头及无岩心钻进工艺

ＤＫＹ９５ＸＨＰ５型地勘牙轮钻头采用了楔形硬质合金镶齿、滑动轴承密封润滑，储油和平衡补偿和新型专利喷嘴等先进结构，使用该钻头及配套无岩心钻进工艺，在中硬砂岩和灰岩中钻进，钻探台效提高，单位进尺成本降低。     

大口径牙轮组合钻头钻进成本的控制

本文分析了大口径牙轮组合钻头钻进成本的构成和提高机械钻速的几个有效途径，提出了提高牙轮钻头使用寿命的措施。     

在复杂地层钻进物探震源孔系列钻头的研制与应用

在密山一带休物探震源孔,外遇地层为胶泥、沙土、风化岩、青石板及河流石等。为此研制了一系列新式钻头,包括９８ｍｍ三牙轮钻头、９８ｍｍ刮刀式ＰＤＣ钻头及１１８ｍｍ砾石流沙炮眼防卡钻头,前２种钻头现场共应用９３０口井,创造了极好的经济效益和社会效益。     

国内外新型牙轮钻头保径结构概述

从牙轮钻头的常规保径结构在现代钻井条件下存在的问题出发，指出了研究开发新型保径结构的必要性，综述了国内外牙轮钻头保径结构的发展动态，强调了研究和应用具有主动切削功能的保径结构对牙轮钻头的重要性。     

CG型液刀钻头及使用效果

介绍了滚刀钻头破岩机理，滚刀的分布规律，以及钻进参数等因素对钻进效果的影响，并通过施工实例对目前滚刀钻头使用中所存在的主要问题进行了分析。     

碎岩刀具工作面圆弧化机理及解决途径

通过分析孕镶金刚石刀头碎岩和磨损机理,找出引金刚石刀头工作端面弧化的原因,并提出了克服圆弧化现象的几种方法。     

Some Attempts for Estimating Rock Strength and Rock Mass Classification from Cutting Force and Investigation of Optimum Operation of Tunnel Boring Machines

Summary. Tunnel face and wall collapse are common during excavations performed by tunnel boring machines (TBMs) due to the difficulty of correctly identifying the properties of the excavated rock. This identification, however, can be simplified by using the cutting force to estimate rock strength, a method that has already proved quite successful in Japanese tunnel excavations. This paper summarizes knowledge relating to the cutting force obtained through tunnel excavation experience, and the relationship between rock strength and TBM operation is discussed. Although TBM operators rely on intuition to set the cutter head speed appropriately, this decision process represents a logical method of operation that takes advantage of the variable speed capability of the cutter head. Selection of appropriate support methods for the excavated face is also a critical issue in tunnel excavation. This selection process is based on the condition of the rock, which is difficult to determine quickly and accurately during tunnel excavation. The present paper uses the excavation of two tunnels to demonstrate that it is possible to assign rock mass classifications accurately based on rock strength when boring a uniform rock type. It is also shown that the rock mass can be classified from the rock strength normalized by the uniaxial compressive strength when boring through mixed rock types.     

复合式土压平衡盾构刀盘失效风险分析

通过对复合式土压平衡盾构刀盘失效的事故种类及原因的分析与总结,应用故障树分析（FTA）方法对刀盘失效风险进行了研究,建立了刀盘面板、刀具和其他刀盘体系的故障树系统模型。通过定性与定量分析,讨论了各项风险事故的潜在失效模式和影响因素。结合具体工程进行了应用,并提出了针对性的控制措施。研究有助于复合式土压平衡盾构刀盘的设计、施工的决策与控制。     

中硬岩层钻进孕镶金刚石复合片钻头的研究与应用

针对中硬岩层的特点设计了一种孕镶金刚石复合片钻头,介绍了其切削结构、特点及切削原理。在钻进中硬岩层时,复合片切削齿和孕镶金刚石后支撑能够共同发挥切削作用,提高钻头钻进效率和钻头的稳定性并且能使钻头具有较长的寿命。     

截齿截割煤体变形破坏过程的红外热像研究

对截齿截割煤体变形破坏过程的红外热像进行测量和分析,从而研究截齿截割作用下煤体变形破坏规律。改变截齿类型、截割速度、截深、测量方位等测量煤体红外热像,发现扁齿截割时在垂直截割方向与扁齿凸脊相应处出现条状高温区;锥齿截割时在齿尖附近出现点状高温区;截割速度越快,热效应越明显。截齿截割煤体过程中,温度场中最高温度值与截深及煤体力学性质有关。截深越深,温度场中最高温度越高;煤体的抗拉强度、抗压强度、黏结力、内摩擦角越大,高温区的最高温度越高。     

Deep-Seated Slope Failures Induced by Inappropriate Cutting in China

Given insufficient geological investigation and inadequate interpretation of geological settings, remedial works for localized cut slope collapses may induce large-scale failures and cause remarkable damage, as well as economical loss. A number of recent reports have addressed individual large-scale failures due to inappropriate cutting, but the systematic classification of failure patterns has received less attention. In this study, a re-profiling triggered landslide is described in detail. The deep slip surface is located by field measurements; then, the stability of the slope before and after cutting is assessed with the limit equilibrium method. Three types of slopes prone to deep-seated failures are introduced: the loose deposits type, the ancient landslide type, and the deep adverse discontinuities type. The mechanism of each failure pattern is illustrated with a case study. The stability analyses indicate that inappropriate slope profiling may greatly reduce the factor of safety (FS) of a slope. Recommendations are given for mitigating the deep-seated landslide induced by inappropriate cutting, and a case history of successful measures is presented.     

Characterization of Effective Parameters in Abrasive Waterjet Rock Cutting

The rock cutting performance of an abrasive waterjet is affected by various parameters. In this study, rock cutting tests are conducted with different energy (i.e., water pressure, traverse speed, and abrasive feed rate), geometry (i.e., standoff distance), and material parameters [i.e., uniaxial compressive strength (UCS)]. In particular, experimental tests are carried out at a long standoff distance (up to 60 cm) to consider field application. The effective parameters of the rock cutting process are identified based on the relationships between the cutting performance indices (depth, width, and volume) and parameters. In addition, the cutting efficiency is analyzed with effective parameters as well as different pump types and the number of cutting passes considering the concept of kinetic jet energy. Efficiency analysis reveals that the cutting depth efficiency tends to increase with an increase in the water pressure and traverse speed and with a decrease in the standoff distance and UCS. Cutting volume efficiency strongly depends on standoff distance. High efficiency of cutting volume is obtained at a long standoff distance regardless of the pump type. The efficiency analysis provides a realistic way to optimize parameters for abrasive waterjet rock excavation.     

利用鱼嘴构造恢复岩层初始厚度的初步方法

作为一种由于岩石能干性差异而形成的构造形迹，鱼嘴构造对于研究岩石变形和岩石流变性质具有独特的意义。基于此，根据其发育程度，将鱼嘴构造划分成 A、B、C、D、E5种基本类型，研究了鱼嘴构造的形态特点以及鱼嘴的周缘长度与岩层初始厚度之间的关系，利用物理模拟的手段，模拟出 B、C、D、E4种类型的鱼嘴构造，相应地得出了利用这 4类鱼嘴构造恢复岩层初始厚度的系数 K 1、K 2，K 3，K 4并成功地运用于实际岩石能干层初始厚度恢复。     

澳门美高梅金殿工程大口径钻孔扩底灌注桩施工技术

澳门美高梅金殿工程主楼基础为38根钻孔扩底灌注桩，桩孔直径为3m扩底到4．2-4．5m，场地狭窄，且是在微风化花岗岩中扩底。根据工程的具体情况，采用贝诺特工法、反循环四翼刮刀钻头钻进、滚刀钻头钻进等组合钻进工艺，同时采用在港澳地区限制严格的泥浆护壁钻进。为港澳地区用泥浆钻桩孔作出了典范，且取得了良好的经济效益。