麻省理工學(xué)院設(shè)計的大型木材建筑
MIT champions large-scale timber architecture with Longhouse proposal
John Klein領(lǐng)導(dǎo)了麻省理工學(xué)院學(xué)生用大量木材設(shè)計了一座大型社區(qū)中心，他認(rèn)為木材是更可持續(xù)的建筑業(yè)的關(guān)鍵材料。
該建筑名為“長屋”（The Longhouse），其結(jié)構(gòu)高40英尺，由單板層積材（LVL）制成，這一種新型的工程木制品，能夠承受高水平壓力。
這種材料支撐起長屋的巨大封閉空間，長為140英尺（43米），寬為50英尺（15米），連續(xù)的屋頂沒有任何內(nèi)部結(jié)構(gòu)支撐。
木材提供生態(tài)友好型建筑方案
麻省理工學(xué)院建筑系的研究科學(xué)家Klein說，像LVT這樣的木材提供了一種可持續(xù)的替代鋼鐵混凝土的方法，同時在經(jīng)濟上也相當(dāng)可觀。
Klein告訴Dezeen的記者：“對于六層以上的建筑，我們的木材技術(shù)從成本上已經(jīng)超越了混凝土和鋼結(jié)構(gòu)方案?！?/p>
“大型木結(jié)構(gòu)建筑為住房和減少碳排放提供了一個有效的解決方案，也為城市擴張問題提供了一個可持續(xù)的解決方案。”
Wood is the key to a more sustainable building industry, says architect John Klein, who has led Massachusetts Institute of Technology students in designing a large community centre from mass timber.
The Longhouse is a 40-foot-high structure to be made from laminated veneer lumber (LVL), one of a new class of engineered wood products that are able to withstand high levels of stress.
The material would allow the Longhouse to contain a large enclosed space – 140 feet (43 metres) long and 50 feet (15 metres) wide – that is uninterrupted by any internal structural supports.
Mass timber offers eco-friendly construction option
Klein, a research scientist in MIT's architecture department, said that mass timber like LVT offered a sustainable alternative to concrete and steel, and had become economically viable as well.
'At heights above six stories, mass-timber technologies have begun to compete economically with concrete and steel building solutions,' Klein told Dezeen.
'Mass-timber buildings offer a promising solution for housing and carbon reduction goals, in addition to providing a sustainable solution for cities to address urban sprawl.'
與排放密集型的混凝土相比，大型木結(jié)構(gòu)的生產(chǎn)影響低且無毒。它還有一個額外的好處就是儲存大氣中的碳，這些碳在樹生長的時候就儲存在了木材中，Klein說：“建筑就是碳的儲存器?！?/p>
美國的一些建筑已經(jīng)開始使用大型木結(jié)構(gòu)，例如馬薩諸塞大學(xué)內(nèi)John W Olver設(shè)計的四層建筑，但Klein表示，他們正在落后于歐洲、澳大利亞和加拿大等國。
北美的大型木結(jié)構(gòu)建筑仍然滯后
他告訴Dezeen的記者：“目前北美的建筑規(guī)范不支持建設(shè)六層高度以上的大型木結(jié)構(gòu)建筑，這一障礙極大地限制了在中等海拔范圍內(nèi)大量木材的使用?！钡惭a充說國際建筑規(guī)范有希望在2021年進行重新修訂。
在波特蘭（美國俄勒岡西北部港市）建造的一座12層高的建筑本來計劃成為北美最高的木建筑，但因為開發(fā)商降低了預(yù)算，導(dǎo)致其上月被擱置。
麻省理工學(xué)院建筑系的大型木結(jié)構(gòu)設(shè)計團隊的學(xué)生們設(shè)計的“長屋”（The Longhouse）旨在挑戰(zhàn)建筑規(guī)模，而不是高度。
該建筑旨在成為一個靈活的社區(qū)空間，并包含合作、社交活動及運動等多種用途，該建筑由6英寸厚（15厘米）的LVL面板切割而成的一系列拱門組成。
這些拱門呈折疊式排列，可容納大量的太陽能電池板，也可以供自然光透過。
In contrast to emissions-intensive concrete, mass-timber production is low-impact and non-toxic. It also has the additional benefit of storing carbon from the atmosphere that has been sequestered by the tree as it grew. 'The building is a carbon sink,' said Klein.
Mass timber has already been used in several US buildings — including the four-storey John W Olver Design Building at the University of Massachusetts Amherst — but Klein says the country is falling behind the likes of Europe, Australia and Canada.
North America's mass-timber adoption still lagging
'The current North American building codes do not support mass-timber building prototypes with above six stores, an impediment which significantly limits the implementation of mass timber in the mid-rise range,' he told Dezeen, though adding that he expects the International Building Code — the basis for most US jurisdictions — to change in 2021.
Plans for a 12-storey building in Portland that would have become the tallest all-timber building in North America were put on hold last month, which the developers put down to cost.
The Longhouse — designed by cross-disciplinary students in the Mass Timber Design workshop in MIT's architectural department — aims more for scale than height.
Intended to be a flexible community space used for purposes such as co-working, social events and exercise classes, the building would comprise a series of arches cut from six-inch-thick (15-centimetre) LVL panels.
These arches are arranged in a pleated pattern that accommodates plenty of solar panels, and creates windows for natural light and passive solar heating.
麻省理工學(xué)院建筑學(xué)碩士研究生Demi Fang說：“這是一個有趣的設(shè)計過程，它結(jié)合了工程和美學(xué)，最終讓我們完成每個拱單元作為空心三角形截面的方案?！?/p>
她說：“通過建立三角形截面所達到的結(jié)構(gòu)深度可以幫助我們達到公共空間所需的清晰跨度。同時使建筑內(nèi)外都形成最好的視覺效果?！?/p>
“因拱門的每一點受力大小不均勻，所以其沿著長度方向逐漸變細(xì)，這種變化的橫截面既結(jié)合了結(jié)構(gòu)性能，又節(jié)省了材料?！?/p>
拱門為預(yù)制件，在現(xiàn)場使用螺栓連接在一起。
“長屋”將于本年10月于緬因州材料業(yè)大會（Maine Mass Timber Conference）上展出。
盡管目前還沒有建造它的計劃，但Klein下一步將在制造和工程合作伙伴的幫助下在新英格蘭建立一個示范模型。項目基金由美國農(nóng)業(yè)部2018年木材創(chuàng)新基金資助。
'An interesting design process incorporating engineering and aesthetic considerations ultimately pointed us towards the idea of building up each arch element as a hollow triangular cross-section,' said Demi Fang, a graduate student in MIT's Master of Science in Architecture Studies.
'The structural depth achieved by building up the triangular section helps us achieve the clear span desired for the communal space, all while lending a visual language on both the interior and the exterior of the structure that we thought worked well,' she added.
'Each arch tapers and widens along its length; because not every point along the arch will be subject to the same magnitude of forces, this varying cross-section depth both expresses structural performance while encouraging material savings.'
The arches would be prefabricated and bolted together on-site.
The Longhouse will be presented this October at the Maine Mass Timber Conference.
There are no plans to build it at present, although Klein's next project — funded by a 2018 Wood Innovation Grant from the US Department of Agriculture — will look to build a demonstration model in New England with the help of manufacturing and engineering partners.
