冲刷对于既有结构物基础的承载力及安全稳定性有较大影响,结构物基础最终冲刷深度的预测为结构物基础设计提供理论依据.由结构物基础冲刷产生的防护问题研究也愈来愈受到人们重视,本文从实体抗冲与减速不冲角度对传统防护方法进行介绍,现有传统防护方法对结构物基础有较好的防护效果,但针对深远海域海上结构物基础的防护有很大的局限性.

为探讨桩端阻力和桩侧摩阻力对静压桩贯入机制的影响以及贯入过程中的荷载传递规律,通过在桩身埋设光纤光栅(FBG)传感器,对足尺闭口PHC管桩静力压入层状土地基的沉桩过程进行监测.试验结果表明:光纤光栅传感器的稳定性好、抗干扰性强,对桩身应力的监测效果较好;压桩力的变化规律基本反映了土层的分布情况,桩端土层的软硬程度制约着压桩力的变化;桩端由黏土层进入到粉土层时,压桩力平均增加2.5倍,桩侧摩阻力平均增加1.7倍且占沉桩阻力的44.99％;桩端阻力受桩端土性的影响较大,粉土层的桩端阻力约为黏土层的2倍且占沉桩阻力的59.84％;桩端由硬土层进入软土层时,需考虑沉桩速度和桩身表面切向力对桩侧摩阻力的影响;在沉桩过程中,随着贯入深度的增加,同一标高处桩侧水平应力逐渐释放,桩侧摩阻力不断减小且其退化现象明显.

In the process of urban rail transit construction, underground excavation method is often used in subway station construction. Based on a large number of measured data of Qingdao Metro Line 3, this paper analyzes and studies the ground subsidence law of long-span shallow buried excavation station. The research results show that vertical surface settlement will be caused by the excavation of both sides of the guide hole, but the settlement is relatively small, basically within −10 mm. Large surface settlement will occur during the middle or middle guide hole excavation, with a large settlement up to −30 mm. Through data fitting, it is found that the regression analysis using cubic polynomial of one degree can get better fitting effect. The horizontal surface variation rules of underground excavation stations are affected by the tunnel depth, geological conditions, management level of monitoring units, monitoring layout and monitoring accuracy, and so on. The differences in horizontal surface deformation and settlement between stations are large. Wannianquan Road Station basically conforms to the deformation law of ground settlement trough in Peck, and Junfeng Road Station directly above belongs to the whole subsidence type. This study has accumulated a large number of surface settlement monitoring data, which can provide a certain reference for the subsequent design of similar lines.

作为房建工程的组成部分之一,地基基础在维持房建结构的稳定、安全、可靠方面起到的作用不容忽视.文章阐述了房屋建筑地基基础加固工程施工的重要性,分析了房屋建筑地基基础加固工程施工的特点,探讨了房屋建筑地基基础加固工程的施工技术.

为满足大型磨机端盖和中空轴铸件的性能要求,对ASTM A216标准WCA铸钢材料的化学成分和热处理工艺进行研究和调整.取消添加Cr、Ni、Mo元素,将化学成分中Mn元素含量提高,热处理时加强冷却措施.经过调整,铸钢材料的屈服强度稳定在330～370 MPa,抗拉强度540～600MPa,伸长率26％～32％,达到了规定要求.

分析了碱酚醛树脂砂的硬化机理及碱酚醛树脂砂的合成工艺.针对碱酚醛树脂砂的特性,确定合适的型砂工艺参数,制定相应的型砂操作规程.在大型铸钢件的生产中,应用碱酚醛树脂砂可有效提高铸件表面质量及力学性能,并减少清理的周期和费用.

我国经济的快速发展离不开工业的大力支持,大型钢铸件作为工业发展的的重要方向之一,其代表了一个国家工业发展的重要水平.大型长圆筒状铸钢件是在工业生产中应用较多的一种产品,其铸造质量的好坏及铸造效率直接影响着大型圆筒状铸钢件的生产.本文主要在提出一种新型的大型圆筒状铸钢件铸造工艺的基础上,对新型与传统两种应用于大型圆筒状铸钢件的铸造工艺进行对比分析介绍.

The upper and lower dies of 217 ton hook are important dies for producing the double hook of crane, belonging to thick wall casting, which bear high temperature and huge load when being used, so the property requirements are very high. The structures of the upper and lower dies of hook with outline dimension 2120 mm × 1760 mm × 500 mm, ZG310-570 and main wall thickness 500 mm, were analyzed in the paper. Casting process toward manufacturing difficulty was designed according to conditions of the company. The upper and lower dies of hook were produced successfully.

Cone crusher top rack body is a kind of large steel casting that has high quality requirements.In order to improve the yield and rate of qualified products of the rack body for cone crusher,through the analysis on the structure of the casting and usage of module calculation method,casting process was optimized by improving gating system and increasing surface chill.After optimization,the technological yield increased and high-quality casting could be stably produced,which provided valuable experience for the future production of such castings.

The tests on the soil compaction and unconfined compressive strength treated by adding aqueous solution of curing agent were carried out and a comparison with the soil added the ISS of South Africa was made.Through laboratory experiments,this paper studied whether the strength and density of the soil added curing agent increased or not.The results showed that after adding curing agent,the soil plasticity index decreased,the maximum dry density increased,the unconfined compressive strength improved,and it had more remarkable effects than the soil added the ISS of South Africa.

The large half-ring gear has casting defects such as distortion,dispersed shrinkage,shrinkage and cracks,etc.Optimization measures were adopted as follow: the body of large half-ring gear was divided into some parts;each modulus was calculated,in order to design the size of every riser;suitable gating system design;layout of chill.After optimization,the casting defects such as distortion,dispersed shrinkage cavities and shrinkage disappears,the technological yield increases and it could stably produce a high-quality casting.

It was presented the discoloration mechanism and peripheral influencing factor of the thermopaint.Meanwhile,it was prospected the development trend of the thermopaint in this article.

Although the FRP has been abundantly studied at home and abroad,there are many uncertain factors in practical projects.suffered from composition,processing technique,bonding methods and other influence factors,deformation,deflection change and failure mode of composite materials are not consistent with different shape and force of materials.This paper conducted indoor experiment and numerical simulation to H-shaped GFRP beam,and studied the mechanical properties and failure form.