共查询到13条相似文献,搜索用时 78 毫秒
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<正>1引言我国机械制砖工艺出现在20世纪初,且对挤出机的要求不高,此种状况一直延续到20世纪80年代。由于烧结砖采用的原料大多为粘土,长期以往 相似文献
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1 引言
烧结砖瓦工艺的出现已有二三千年的历史,也就是我们通常讲的秦砖汉瓦,但采用螺旋挤出机制砖生产工艺还不足二百年的历史,我国机制砖工艺的出现大约在20世纪初叶,且对挤出机的要求都不高,此种状况一直延续到20世纪80年代。 相似文献
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2 工作原理电动机13经窄V三角带12带动气动离合器11,由气动离合器传递给减速机10,经减速后分别驱动主轴9和压泥板轴8.进人受料箱4的泥料,经泥缸3、机头1、机口2被挤成合乎要求的泥条.为减小挤出时机头、机口处的动力消耗,在机头、机口人口处装有高压润滑系统,不仅显示挤出压力,而且监测制品生产是否始终稳定在同一质量水平上.减速机输出轴与主轴采用夹壳联轴器连接,为确保轴承及密封件的润滑,在联接件5装有永嘉流遍润滑系统,配有独立的油环泵系统抽真空,真空度≥93%.3主要技术特征a.该机挤出压力大,最大挤出压力40kg/cm~2,能真正适应煤矸石、粉煤灰、页岩、炉渣、劣质土等原料的成型.b.为减小挤出阻力,提高砖坯外观质量,在机头.机口处设有高压润滑系统,为实现快速换芯具,采取双机头、双机口设计.C.主轴与轴承组的组合设计更为巧妙,主轴只传递扭矩不承受轴向力;绞刀轮缘与泥缸衬套阻尼条的设计可更好地防止返泥,以提高挤出效率;绞刀变径采取突变的,使加工更方便简单;变换双线绞刀可取得不同的压缩比和产量.d.减速机为中硬齿而专用减速机,压泥板轴.主轴均由减速机直接传递,使受料简化,并设有独立的润滑系统.c.为提高设备工作性能和效率,减少维修及各种辅助时间,该机所有易损件均采用耐磨材料,材料硬度 相似文献
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《Soils and Foundations》2012,52(4):682-697
A comprehensive set of experimental data on Bangkok subsoils from oedometer and triaxial tests are analysed in this paper in order to determine the stiffness and strength parameters for Hardening Soil Model. The parameters determined are the Mohr–Coulomb effective stress strength parameters together with the stiffness parameters; tangent stiffness for primary oedometer loading, secant stiffness in undrained and drained triaxial tests, unloading/reloading stiffness and the power for stress level dependency of stiffness. The oedometer data are obtained from three different Bangkok soil layers: soft clay at 6–8 m depths; medium clay at 12–14 m depths; and stiff clay at 15.5–18 m depths. The triaxial tests data are carried out for soft and stiff clays at depths of 5.5–6 m and of 16–18 m under both undrained and drained conditions, respectively. Finally, two sets of parameters for soft and stiff Bangkok clays are numerically calibrated against undrained and drained triaxial results using PLAXIS finite element software. 相似文献
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根据黄陵—延安高速公路沿线湿软地基的土工实验资料,着重分析了黄土沟壑区湿软地基的物理力学性质以及土性指标间的相关性,提出了相应的回归方程,用以指导对该地区湿软地基物理力学参数的取值。 相似文献
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阐述了深厚软土地基中刚柔性长短桩新型复合地基的设计思想,针对温州软土的构造特点和工程特性,通过在某康居工程中的应用,结合大型现场试验和施工过程桩土应力现场监测,分析了此类复合地基的主要工程性状,研究了该类复合地基桩、土应力和孔压力的发展规律。研究表明,刚性桩和柔性桩应力比值在静载试验和实际工程中规律较一致,孔压消散速度较快,充分发挥了桩间土的承载力特性,研究总结了此类组合桩应用于深厚软土多层建筑地基的工程经验,所得结论可为进一步的理论研究及工程设计提供有益的参考依据。 相似文献
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Mantu MAJUMDER Debarghya CHAKRABORTY 《Frontiers of Structural and Civil Engineering》2021,15(2):537-551
Ensuring a safe foundation design in soft clay is always a challenging task to engineers. In the present study, the effectiveness of under-reamed piles in soft clay underlaid by stiff clay is numerically studied using the lower-bound finite element limit analysis (LB FELA). The bearing and uplift capacities of under-reamed piles are estimated through non-dimensional factors Ncul and Fcul, respectively. These factors increased remarkably and marginally compared to Ncul and Fcul of the piles without bulbs when the bulb is placed in stiff and soft clay, respectively. For a given ratio of undrained cohesion of stiff to soft clay (c2/c1), the factors Ncul and Fcul moderately increased with the increase in the length-to-shaft-diameter ratio (Lu/D) and adhesion factors in soft clay (αs1) and stiff clay (αs2). The variation of radial stress along the pile–soil interface, distribution of axial force in the under-reamed piles, and state of plastic shear failure in the soil are also studied under axial compression and tension. The results of this study are expected to be useful for the estimation of the bearing and uplift capacities of under-reamed piles in uniform clay and soft clay underlaid by stiff clay. 相似文献
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在分析总结由土–水特征曲线预测非饱和土渗透系数方法的基础上,根据Childs和Collis-George(1950)利用充水孔隙空间形状提出的、并经多次修改的预测渗透系数模型,预测了上海非饱和软土的相对渗透系数。上海非饱和软土渗透性参数随吸力(含水率)变化呈现非线性变化,吸力增加(含水率降低)渗透性快速降低。对不同粒径的上海非饱和软土层,在减饱和初期(低吸力阶段),土体中骨架颗粒大小对渗透性影响不大;但随着减饱和过程的进行,大骨架颗粒的土体的渗透性衰减速率大于小颗粒土体;而减饱和后期,这种衰减速率上的差异又趋于不明显。这一衰减特征主要与参与减饱和的土中水的赋存状态有关。 相似文献
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以扶风县法门高中校区规划设计为例,介绍了该校的设计理念,对其总体规划、空间与造型设计进行了分析,指出在校园建筑规划设计中,应着重体现对校园环境与文脉的尊重,积极营造人文氛围的交往空间,并以此提升高中校园的气质与风貌。 相似文献