[雙語(yǔ)翻譯]--港航外文翻譯--碼頭起重機(jī)梁極限荷載（原文）

1、 p:\files\ports2010\submission\ports2010-000309.doc Extreme Loading of Wharf Crane Girders Erik Soderberg1, Michael Jordan2, Patrick McCarthy3, and Anna Dix4 ¹ Liftech Consultants Inc, 344 – 20th Street, #360, Oakl

2、and, CA 94612-3593; Tel: (510)832-5606; Fax: (510) 832-2436; Email: esoderberg@liftech.net 2 Liftech Consultants Inc; mjordan@liftech.net 3 Liftech Consultants Inc; pmccarthy@liftech.net 4 Liftech Consultants Inc; adi

3、x@liftech.net ABSTRACT Wharf crane girders are designed for loads that are likely to occur. Although rare, extreme loads that are not considered in design do occur. Extreme loads result from severe wind, earthquakes,

4、 missing piling, crane collisions, crane collapse, and other abnormal conditions. Extreme loads significantly exceeding the conventionally computed wharf crane girder strength often do not cause significant damage.

5、 This paper presents what happens when wharf crane girders are subjected to extreme loads near or beyond their calculated design capacity, the performance that can reasonably be expected when extreme loads occur, and w

6、hich extreme loads should be considered in the design of wharf crane girders. Topics presented in this paper include: (1) sources and descriptions of extreme loads; (2) case studies of extreme loading events and the

7、 resulting wharf crane girder performance; (3) explanations of wharf crane girder performance and implications for girder design and capacity evaluation; and (4) a discussion of, and recommendations for, reasonable ex

8、treme load design criteria. INTRODUCTION Events that cause extreme crane loads on wharves are rare. Although these loads are anticipated by the crane designer, they are typically not reported to the wharf designer and

9、 are usually not considered in the wharf design criteria. Interestingly, most extreme wheel loads have never caused more than superficial damage to typical heavy short span concrete wharves. This paper presents so

10、me of the most common extreme loads, discusses why most do not damage the wharf, and recommends wharf design criteria for these loads. 807 Ports 2010: Building on the Past, Respecting the Future © 2010 ASCEPorts 20

11、10 Downloaded from ascelibrary.org by Changsha University of Science and Technology on 01/06/14. Copyright ASCE. For personal use only; all rights reserved.p:\files\ports2010\submission\ports2010-000309.doc Figure 2. Ol

12、eo bumper schematic2 The force in the bumper is developed by viscous forces as the fluid flows through the orifice. The meter valve reduces the size of the orifice as the crane speed is reduced so that the load displa

13、cement curve is nearly rectangular. The maximum energy absorption is developed over nearly the full stroke of a particular bumper compression speed, typically the rated gantry speed of the crane. During collision at

14、 normal maximum operating gantry speeds, the bumpers act as intended and the collision forces equal the bumper rated force. If the speed is excessive, as with a runaway crane, the bumper is, effectively, infinitely st

15、iff, and the bumper force is much greater than the force reported by the manufacturer. The crane collision force with the crane stop is limited by the lateral strength of the crane frame, the stop, or the force requi

16、red to tip the crane. Crane girders resist the extreme collision loads through inertia forces and increased strength due to the high rate of loading. Figure 3. Boom damaged from vessel collision 2 Design copyrighted

17、 by Gantrex, printed with permission. 809 Ports 2010: Building on the Past, Respecting the Future © 2010 ASCEPorts 2010 Downloaded from ascelibrary.org by Changsha University of Science and Technology on 01/06/14. C