請幫忙轉做”英文”..thx

2008-03-13 6:59 am

從鐵道部青藏鐵路辦公室提供的資料顯示，以往在多年凍土區修建鐵路，主要採取增加路堤高度和鋪設保溫材料等措施，隔斷或減少外界進入路基下部的熱量，從而阻止或延緩多年凍土退化。大量工程實踐表明，這種方法不能從根本上改善路基的熱物理狀態。青藏鐵路確立了“主動降溫、冷卻地基、保護凍土”的設計思想，使凍土工程設計實現了“三大轉變”，即：對凍土環境分析由靜態轉變為動態；對凍土保護由被動保溫轉變為主動降溫；對凍土治理由單一措施轉變為多管齊下、綜合施治。

以下為整套工程措施:

1. 片石氣冷措施 - 片石氣冷路基是在路基墊層之上設置一定厚度和空隙度的片石層，因片石層上下介面間存在溫度梯度，引起片石層內空氣的對流，熱交換作用以對流為主導，利用高原凍土區負積溫量值大於正積溫量值的氣候特點，加快了路基基底地層的散熱，取得降低地溫、保護凍土的效果。

2. 碎石（片石）護坡或護道措施 - 在路基一側或兩側堆填碎石或片石，形成護坡或護道。碎石（片石）護坡空隙內的空氣在一定溫度梯度作用下產生對流，寒季碎石（片石）內空氣對流換熱作用強烈，有利於地層散熱，暖季碎石（片石）內空氣對流作用減弱，對熱量的傳入產生遮罩作用，減少了暖季的傳熱，達到了降低地溫、保護凍土的效果

3. 通風管措施 - 在路基內橫向埋設水準通風管，冬季冷空氣在管內對流，加強了路基填土的散熱，有利於降低基底地溫，提高凍土的穩定性

4. 熱棒措施 - 熱棒是利用管內介質的氣液兩相轉換，依靠冷凝器與蒸發器之間的溫差，透過對流迴圈來實現熱量傳導的系統。青藏鐵路有32公里路基採用了熱棒措施

5. 此外還有遮陽棚、隔熱保溫、基底換填、路基排水、路橋過渡段、橋涵基礎等等。

回答 (1)

Wong

2008-03-13 7:20 am

✔ 最佳答案

The Ministry of Railways Qinghai-Tibet railway Office provides the material demonstrated that formerly in many year frozen earth area construction railroad, mainly adopted increases the embankment highly and lays down measures and so on thermal insulation material, separates or the reduced outside enters lower part the roadbed the quantity of heat, thus prevents or delays many year frozen earth degeneration. The massive project practice indicated that this method cannot fundamentally the improved subgrade hot physical state. The Qinghai-Tibet railway has established “the initiative temperature decrease, cools the ground, the protection frozen earth” the design concept, caused the frozen earth engineering design to realize “three big transformations”, namely: Transforms to the frozen earth environment analysis by the static state into dynamic; Transforms to the frozen earth protection by the passive heat preservation into the initiative temperature decrease; Transforms to the frozen earth government by the sole measure into multibarreled uneven, the synthesis treats.
The following is whole set mechanical control measure:
1. The slabstone air cooled measure - slabstone air cooled roadbed is establishes certain thickness and the voidage piece riddlings above the roadbed breaker strip, because the piece riddlings during high and low interface has the gradient of temperature, causes in the piece riddlings the air convection, the heat change function take the convection as the leadership, is bigger than the accumulated temperature size using the plateau frozen earth area negative accumulated temperature size the climate characteristic, sped up the roadbed basis stratum radiation, obtains reduces the ground temperature, the protection frozen earth effect

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