基坑验槽在岩土勘察中的意义

对基坑验槽时必须具备的资料和条件进行了介绍,说明了无法验槽的情况,并结合具体案例,对天然地基、桩基、土岩结合的验槽技术作了详细分析,以把好基础施工质量关,保证地基的安全可靠性。     

天然地基验槽与局部处理

阐述了验槽的单位组成及验槽的目的,介绍了验槽具备的条件和资料及验槽的内容,针对验槽中出现的问题提出了处理措施,并指出验槽中出现的问题以局部问题为多,局部地基处理要与整个建筑物地基统一考虑,以免造成处理后的地基不均匀沉降。     

关于地基验槽的若干注意事项

简要介绍了地基验槽的程序,验槽所需条件及验槽的方法,对在地基验槽时可能出现的各种情况按照相关的规定及笔者自己的意见给出了处理办法.     

浅谈建筑施工企业如何验槽

介绍了验槽前的准备工作及验槽时必须具备的资料和条件，详细阐述了建筑施工企业在基坑（槽）验收时应着重注意的几种情况及验槽的方法，可供建筑施工企业验槽时参考。     

议地基基础工程验槽

分析了地基基础工程验槽的重要性,阐述了地基验槽前后应注意的事项,分述了浅基础、深基础和复合地基等不同基础形式的验槽重点,归纳总结出以后做好验槽工作的措施,从而积累验槽工作经验,妥善处理好基槽问题。     

建筑地基验槽及地基的局部处理

阐述了地基施工过程中地基验槽的组织、实施、验槽的基本程序及对地基局部处理方法的总结，同时强调地基验槽中钎探的重要性。     

浅谈地基基础工程验槽

针对地基验槽的重要性,阐述了地基验槽前后应注意的事项,分述了各种形式的基础工程的验槽重点,归纳总结出做好验槽工作的措施,从而保证建筑工程质量,防止事故的发生。     

复杂地质条件下冲孔桩持力层岩性判定及泥浆处理

对广东LNG接收站复杂地质条件下大型泥浆护壁冲孔桩持力层的岩性判定问题进行具体分析,并根据施工条件制定桩基验槽的一般程序,同时对冲孔桩施工中泥浆的制备与处理提出具体方法。     

住宅地基验槽重点简说

基础施工质量对整体住宅质量和安全而言举足轻重,而地基验槽是保证基础施工质量的重要举措。在实际工作中,建筑物对地基的要求不同,基础形式相应多种多样,验槽重点也各不相同。1、浅基础在地质条件较好的情况下多层砖混住宅常常采用浅基础。浅基础主要有条形基础、     

岩溶地区地基基础土洞治理技术——以龙岩市龙雁大道一期安置房A标段工程为例

岩溶地区地质复杂,常暗伏土洞。本文以龙岩市雁石镇一建筑工程项目为例,在地基验槽时发现表层有土洞,验槽各方建议对地基基础土洞进行处理,通过采用充填注浆土洞处理技术,有效消除地基基础安全隐患和危害,为类似工程地质条件下的土洞处理提供参考。     

地基工程的验槽与地基的加固处理

结合工程经验,介绍了地基工程验槽与加固处理的一些方法与体会,供同行参考。     

Development of fatigue test method and improvement of fatigue life by new functional steel plates for welding of trough rib and deck plate of orthotropic decks

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs “trough ribs” and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM (Finite Element Method) analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA (Fatigue Crack Arrester). Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges.     

软土地区盾构隧道施工沉降槽的特征分析

根据实测资料 ,分析了上海软土地区盾构隧道施工时所形成的沉降槽的特征。通过统计、拟合、对比及作图等方法 ,对沉降槽的形状、沉降槽与隧道埋深的关系、沉降槽随时间的演变以及沉降槽宽度系数与埋深和时间的关系进行了深入的研究 ,得出了在软土地区具有重要指导意义的结论。     

黏土中隧道开挖引起的地表及地表以下土体长期 沉降计算方法

基于 Mair 提出的隧道开挖引起的土体瞬时沉降的理论以及进行的有限元数值模拟结果,推出地表及地表以下不同深度土体长期沉降的计算方法。首先模拟了 Ong 的离心机试验以验证数值模型的合理性,然后对隧道开挖引起的不同深度处土体长期沉降问题进行了模拟研究,建立了长期和瞬时情况下地层损失率之间的关系,并推导出长期情况下各深度处沉降槽宽度系数和最大沉降值的计算式,从而可确定沉降槽的形状。经与现场实测资料和数值模拟结果对比,验证了方法的合理性,可作为实际工程的借鉴。     

槽型抛物面聚光集热器分析

槽型抛物面聚光集热器是槽式太阳能热发电系统的关键部件。在热力学第一定律和热力学第二定律的基础上,结合槽式太阳能热发电系统模型,对槽型抛物面聚光集热器进行分析。以SEGS-VI槽式太阳能电站设计参数为根据,采用能量系统的白箱模型分析,计算得到各过程的耗散和槽式太阳能聚光集热器的损失和效率,并揭示系统中用能不合理的"薄弱环节"。     

浅埋地铁隧道施工影响下含空洞地层的变形特征分析

地层空洞的存在使得隧道结构周围的地层环境变得更为复杂,在地铁隧道施工的影响下极易引起地表沉降加剧甚至地表坍塌。针对V级围岩地铁隧道,采用三维模型试验和数值模拟研究了不同位置地层空洞对地表沉降的影响规律以及空洞的变形特征,同时通过修正后的Peck公式对试验结果进行拟合分析。研究结果表明:空洞的存在使得地层损失加剧,地表沉降槽深度和宽度均有所增大,沉降槽曲线整体向空洞一侧偏移,通过修正后的Peck公式能较好地拟合出沉降曲线形态;从地表整体沉降形状上看,空洞上方一定范围内地表沉降较大,地表会出现明显的沉降盆形态;综合考虑空洞对地表沉降槽宽度和深度以及地层损失率的影响,认为空洞位于隧道斜上方是最不利位置,在施工过程中对这一方位地层空洞应重点关注;不同方位空洞的变形模式不同,主要表现为立式椭球体和卧式椭球体等变形模式。     

Online‐Monitoring des Temperaturzwangs für ein Trogbauwerk am Hauptbahnhof Berlin infolge Kopplung des Trogs mit der Unterwasserbetonsohle

Online‐monitoring of thermal restraint for a trough structure at the main station Berlin caused by the coupling of the trough and underwater concrete slab. At the main station of Berlin the North–South and East–West main railway lines intersect. The N‐S lines are located at the lowest level of station. They run on both sides of the station in tunnels. The trough structure N begins at the northern end of tunnel and guides the N‐S lines to ground level. The structural design of trough proved to be complex. The high ground water pressure required the coupling of the trough slab with the underwater concrete slab being back‐anchored by injection piles. These piles had to be extended into the trough slab and anchored there. For the coupling of the slabs several structural alternatives were investigated, in order to study their effects on the restraint of the trough slab due to temperature and shrinkage. Studies showed that the temperature load requirements of existing specifications in‐adequately reflect the representative winter situation of Berlin. Realistic temperature values were derived on basis of meteorological and thermal analyses. For the assessment of the efficacy of shear bond between the underwater concrete slab and trough slab, on‐site tests were performed. Expert opinions formulated the necessary design values. In view of the complex structural model of trough and of various assumptions, the owner DB decided the online monitoring for a representative trough. Monitoring is being performed by the MPA Braunschweig. Measurements commenced in July 2003 with the casting of the trough slab and will continue well into the service stage of structure. This report deals with the measuring techniques and with the results prior to the on‐set of railway traffic. All assumptions relevant to the thermal restraint could be verified by the measurements.     

地下连续墙槽壁稳定性分析及护壁泥浆性能指标的确定

本文论述了地下连续墙槽壁稳定的机理,建立了槽壁稳定计算的数学模型,对影响槽壁稳定的诸种因素作了定量分析,并提出了确定护壁泥浆各项性能指标的方法及参数,编制了泥浆配比设计的程序框图,可供地下连续墙的设计与施工时参考。