岩石膨胀性试验注意事项探讨

从室内试验的角度来探讨几类工程勘察中岩石常用膨胀性试验(自由膨胀率、膨胀力、侧向约束膨胀率、耐崩解)的注意事项,从野外取样、标准样品制取、试验操作、方法选择等方面进行了论述,力求减小试验误差,提高膨胀岩的试验水平,保证试验结果的准确性,并使膨胀岩膨胀性指标的测定方法更臻完善。     

隧道地震响应数值模拟研究

在进行隧道地震响应的数值模拟研究时, 横向计算范围和人工边界等对计算结果有很大的影响。本文以黄草坪隧道为研究对象, 应用有限差分程序FLAC3D对其进行地震响应的数值模拟研究, 将横向计算范围分别取为隧道洞径的5倍、6倍、7倍、8倍、9倍和10倍, 并分别采用FLAC3D中的截断边界、自由场地边界和粘性边界进行计算。研究结果表明, 当地震波为P波时, 横向计算范围取为洞径的7至8倍, 人工边界采用自由场地边界或粘性边界是比较合理的。     

桩-桩水平振动动力相互作用研究

在采用动力Winkler地基模型并考虑了被动桩与桩周土体相互作用的基础上,运用传递矩阵法求解出层状地基中的群桩水平振动桩-桩动力相互作用因子。与严格解（Kaynia和Kausel,1982年）进行对比,验证了方法的有效性。研究了各因素如桩长、桩底约束、桩间角度以及地基土对桩-桩动力相互作用因子的影响,并提出了＂影响桩长＂的概念。     

对穿时普遍性的解释

穿时是沉积地层的基本属性,其根本原因是地层的形成作用,即沉积作用本身。有沉积作用就有穿时(侧向加积);或者小范围内不穿时但大范围内必穿时(纵向加积)。海水进退只能影响穿时的具体形式而不是穿时的本质原因或必要条件。板块的运移和增生不仅造成了沉积地层的穿时,还造成了火山地层的穿时。这种穿时与沉积作用直接引起的穿时有本质不同,本文称之为构造穿时。     

天津吹填软土的真三轴卸荷试验研究

利用刚柔复合型真三轴仪对天津吹填软土进行真三轴试验,针对基坑开挖侧向卸荷变形特性进行不固结不排水条件模拟试验研究,控制大主应力△σ≈0、中主应变ε2≈0、小主应力方向卸荷。结果表明：侧向卸荷土体的初始卸荷模量随着围压的增大而增大,卸荷曲线ε1-ε3呈线性关系,泊松比与经典土力学相悖,μ31〉0．5且卸荷剪切过程中随着围压的增大而变大,孔隙水压力在卸荷剪切过程中先增大后减小。     

区域气候模式侧边界的处理对东亚夏季风降水模拟的影响

在区域气候模式模拟中,侧边界的作用是引入大尺度强迫场。如何处理好侧边界,即大尺度强迫场和区域气候模式本身之间的关系问题,对于区域气候模式模拟和预报东亚夏季风降水具有重要意义。本文利用美国纽约州立大学Albany分校的区域气候模式（SUNYA-ReCM）,设计了两种不同的侧边界处理方法,来探讨侧边界对东亚夏季风降水模拟的影响。驱动区域模式的大尺度强迫场来自欧洲中期天气预报中心（ECMWF）及热带海洋大气研究计划（TOGA）的分析资料场。试验结果表明:（1）当模式的区域较大时,采用较小的侧边界缓冲区会在缓冲区与模式内部的交界处产生不连续;扩大缓冲区并且考虑不同尺度强迫在垂直方向上的不同作用,可以避免这一缺陷。（2）更重要的是采用后一种方案,即减少了区域气候模式在模拟大尺度环流场方面所起的作用,使得模式更多地依赖侧边界来得到更真实的、对东亚夏季风降水起重大影响的一些气流,如副高、西南季风和南海季风,对东亚夏季风降水无论是在大小上还是在雨带位置的演变上都能进行更好的模拟。     

SILTATION RATE IN A TRENCH DREDGED ON FLOODPLAIN IN ESTUARY

I. INTRODUCTIONA discharge of 100--200 m3 / s is needed to be diverted from a tidal reach and utilized as cooling water for a Droposed power plant in the Yangtze Estuary. The diversionchannel is divided into two parts by a levee along the river bank, an open channel stretchinside the levee is connected with a trench dredged on the floodplain, as shown in Pig. 1.Since the flow and sediment regimes in these two stretches are different, analysis is madeseparately for each of them.11. ESTI…     

Lateral load pattern in pushover analysis

The seismic capacity curves of three types of buildings including frame, frame-shear wall and shear wall obtained by pushover analysis under different lateral load patterns are compared with those from nonlinear time history analysis. Based on the numerical results obtained a two-phase load pattern; an inverted triangle (first mode) load pattern until the base shear force reachesβ times its maximum value, V_max, followed by a (x/H)^α form, hereβ and α being some coefficients depending on the type of the structures considered, is proposed in the paper, which can provide excellent approximation of the seismic capacity curve for low-to-mid-rise shear type buildings. Furthermore, it is shown both the two-phase load pattern proposed and the invariant uniform pattern can be used for low-to-mid-rise shear-bending type and low-rise bending type of buildings. No suitable load patterns have been found for high-rise buildings.     

空腔结构复合填充墙-钢框架抗侧力性能试验研究

通过空腔结构复合填充墙-钢框架和同尺寸纯钢框架的对比试验，分析了空腔结构复合填充墙-钢框架的抗侧力性能和滞回性能。研究结果证明空腔结构复合填充墙是一种理想的抗侧力体系，可用于多层或小高层钢结构住宅，作为结构的抗侧力构件。     

Field survey of the 1994 Mindoro Island,Philippines tsunami

This is a report of the field survey of the November 15, 1994 Mindoro Island, Philippines, tsunami generated by an earthquake (M=7.0) with a strike-slip motion. We will report runup heights from 54 locations on Luzon, Mindoro and other smaller islands in the Cape Verde passage between Mindoro and Luzon. Most of the damage was concentrated along the northern coast of Mindoro. Runup height distribution ranged 3–4 m at the most severely damaged areas and 2–4 in neighboring areas. The tsunami-affected area was limited to within 10 km of the epicenter. The largest recorded runup value of 7.3 m was measured on the southwestern coast of Baco Island while a runup of 6.1 m was detected on its northern coastline. The earthquake and tsunami killed 62 people, injured 248 and destroyed 800 houses. As observed in other recent tsunami disasters, most of the casualties were children. Nearly all eyewitnesses interviewed described the first wave as a leading-depression wave. Eyewitnesses reported that the main direction of tsunami propagation was SW in Subaang Bay, SE in Wawa and Calapan, NE on Baco Island and N on Verde Island, suggesting that the tsunami source area was in the southern Pass of Verde Island and that the wave propagated rapidly in all directions. The fault plane extended offshore to the N of Mindoro Island, with its rupture originating S of Verde Island and propagating almost directly south to the inland of Mindoro, thereby accounting for the relatively limited damage area observed on the N of Mindoro.