巴塞羅那：全尺度的都市規(guī)劃之路

Joan Busquets 文 Written by Joan Busquets 錢麗源 譯 Translated by Qian Liyuan

概述

巴塞羅那是歐洲歷史悠久的地中海城市典范，是加泰羅尼亞自治區(qū)2000多年以來(lái)的省會(huì)，正如其他歐洲南部城市，都具顯著的形態(tài)特征和城市形成軌跡:隨著人口增長(zhǎng)，城市的擴(kuò)張延續(xù)著原有的歷 史城市形態(tài)，而不是空間的重組。

直至2012年，巴塞羅那市區(qū)面積達(dá)到98.21平方公里，擁有162萬(wàn)常駐人口，都市區(qū)面積為636平方公里， 320萬(wàn)常駐人口。其所在的加泰羅尼亞自治區(qū)有近一半的人口居住在僅占自治區(qū)面積1.98%的巴塞羅那市城市中。

從城市地理來(lái)看，巴塞羅那坐落于近海的平原上，且被西南側(cè)的略夫雷加特河、東北側(cè)的貝索斯河以及東部的科索萊拉海岸山脈圍合，城市的最高點(diǎn)位于蒂維達(dá)沃山頂 (海拔512 米)(圖1)。

一直以來(lái)巴塞羅那的城市地理制約著城市空間的擴(kuò)張，尤其是綿延的海岸線城市帶，連通港口與腹地的交通軸線，而后是現(xiàn)代的塞爾達(dá)城市格網(wǎng)城市規(guī)劃。本文將首先闡述當(dāng)今都市化空間怎樣超越城市地理?xiàng)l件，從而影響巴塞羅那的都市區(qū)規(guī)劃。

新城市文化

通過(guò)城市物質(zhì)空間的干預(yù)，我們將發(fā)現(xiàn)都市區(qū)規(guī)劃中關(guān)鍵的切入點(diǎn)和策略。

圖1：巴塞羅那地理情況說(shuō)明， 由海、山和兩條河流構(gòu)成。突出三角洲， 主要的道路軸線和老城區(qū)。Fig.1：Barcelona’s interpretation of its geographical situation， framed by the sea， the mountains and the two rivers.Highlighting the delta，main road axis and historical settlements.

當(dāng)下的大都市維度：新的機(jī)遇空間

二十世紀(jì)八九十年代的巴塞羅那提出城市重建和中心城區(qū)步行街區(qū)規(guī)劃，這為今后的都市發(fā)展奠定了基礎(chǔ)。緊接著，為了在兩條河流之間建設(shè)緊湊化的城市， 依然延續(xù)了塞爾達(dá)城市擴(kuò)張規(guī)劃的網(wǎng)格。由于外環(huán)交通的現(xiàn)實(shí)性更是強(qiáng)化了 這種網(wǎng)格規(guī)劃的延續(xù)性和永恒性。

巴塞羅那都市區(qū)下轄諸多地方行政部門，通過(guò)對(duì)公共空間和公園規(guī)劃的發(fā)展，我 們認(rèn)為這些地方行政部門的職能空間更加寬 松，相比中心城區(qū)的管理機(jī)構(gòu)。這得益于當(dāng) 地市政的需求，并具有一定的地方自治能力。

而今，大都市區(qū)更多受到全球化影響，隨著金融和信息技術(shù)的高速運(yùn)行，將會(huì)造成城市體的失衡。因?yàn)?，我們認(rèn)為，全球化正在以一種標(biāo)準(zhǔn)化模式強(qiáng)迫著城市體發(fā)展趨同;但是，每一座城市具有不同的歷史、規(guī)劃傳統(tǒng)、管理方式，在全球化模式影響下，都市區(qū)規(guī)劃將導(dǎo)致另一種結(jié)果。

城市規(guī)劃與設(shè)計(jì)急需回應(yīng)當(dāng)前新的城市規(guī)劃模式要求。都市區(qū)是開(kāi)放和相互關(guān)聯(lián)的， 傳統(tǒng)的城市規(guī)模太小缺乏靈活性 , 因此我們必 須構(gòu)建大都市使其具備起碼的城市競(jìng)爭(zhēng)力。

那么問(wèn)題是，未來(lái)的城市規(guī)劃依舊解決緊湊型城市的非生產(chǎn)性土地的轉(zhuǎn)型問(wèn)題?還是在都市區(qū)空間尋找更多的機(jī)遇? 或許，我們能通過(guò)一些城市結(jié)構(gòu)手段同時(shí)解答上述問(wèn)題。

我們發(fā)現(xiàn), 城市的發(fā)展并不一定要像 過(guò)去幾十年那樣依賴物質(zhì)化的增長(zhǎng)；相 反地，開(kāi)放式發(fā)展方式是確保高質(zhì)量的整 合社會(huì)結(jié)構(gòu)。

當(dāng)今的大都市不僅為市民提供不再固化的空間，更是具有吸引力、宜人的、高效減壓的、輕松自由的空間。這些城市空間具有創(chuàng)造性，他們可以是沒(méi)有實(shí)際屬性的，或者無(wú)法定義的空間，但是我們可以從此探索新的機(jī)會(huì)，(諸如以下巴塞羅那城市發(fā)展的案例)。

一、濱水區(qū)——大都市的衍生品

從“里貝拉河岸策略”到“奧林匹克濱海區(qū)”

尊重相互城市功能獨(dú)立的前提下提出基礎(chǔ)設(shè)施建設(shè)與城市發(fā)展規(guī)劃的整合策略

圖2：在奧運(yùn)村， 我們可以看到， 城市系統(tǒng)的設(shè)計(jì)和干預(yù)過(guò)程比之前的階段更為復(fù)雜， 但這確保了這些系統(tǒng)的發(fā)展和各種城市動(dòng)機(jī)的參與。在這種情況下， 幾位國(guó)際獲獎(jiǎng)建筑師被邀請(qǐng)參與總體規(guī)劃中的不同的建筑和空間的開(kāi)發(fā)。Fig.2：In the Olympic Village we can see that the process of design and intervention in urban systems is more complex than in previous periods， but this ensures the possible development of these systems and the involvement of the various urban agents.In this case， several prize winner architects were invited to develop different buildings and spaces of the overall proposal.

近幾十年來(lái), 基礎(chǔ)設(shè)施發(fā)展的規(guī)模擴(kuò)大, 導(dǎo)致城市運(yùn)營(yíng)的尺度（城市功能層級(jí)）也相應(yīng)增加，其關(guān)鍵點(diǎn)是如何處理基礎(chǔ)設(shè)施建設(shè)與城市發(fā)展之間尺度控制與相對(duì)獨(dú)立的城市功能關(guān)系。

現(xiàn)實(shí)情況是，基礎(chǔ)設(shè)施項(xiàng)目的規(guī)?？偸潜瘸鞘许?xiàng)目干預(yù)的規(guī)模要大。然而，城市項(xiàng)目的尺度不同于它的規(guī)模。

舉例說(shuō)明，巴塞羅那濱海城市帶最初是鐵路設(shè)施用地，由于市政需要，在這里需要建設(shè)一個(gè)新的環(huán)城道路以及市政管道來(lái)連通城市的排水系統(tǒng)與貝索斯河道的水處理站。自然地，因?yàn)槌鞘泄δ軟Q定了城市項(xiàng)目的尺度，該基礎(chǔ)設(shè)施項(xiàng)目影響了整條海岸線。另一方面，從純粹的城市發(fā)展來(lái)講，需要一個(gè)分散可控的發(fā)展尺度，它是符合城市開(kāi)發(fā)者和當(dāng)?shù)鼐用竦男枨蟆．?dāng)然基礎(chǔ)設(shè)施中的道路、排水系統(tǒng)以及公共空間都具有優(yōu)先性，而后濱海的住宅和商業(yè)地塊在一個(gè)中度規(guī)模的尺度下建設(shè)，最終形成一座綿延5公里海岸的濱海城市帶。

1992年，奧運(yùn)會(huì)為巴塞羅那帶來(lái)新的濱海區(qū)

1992年奧運(yùn)會(huì)為契機(jī)，巴塞羅那城市進(jìn)行了 “特別” 的城市更新項(xiàng)目，尤其是對(duì)城市內(nèi)部的改造, 重新評(píng)估了城市空地和廢棄城市空間, 新建城市（通信和衛(wèi)生）基礎(chǔ)設(shè)施，將城市內(nèi)不同區(qū)塊連通(圖2)。

1992年巴塞羅那的城市項(xiàng)目更像是一種城市主體功能的修復(fù)或者復(fù)原。在城市的連續(xù)性中，建立關(guān)節(jié)性的城市空間，例如奧運(yùn)村的建設(shè)以三角形基址激活更大范圍的城市轉(zhuǎn)型(圖3)。

奧運(yùn)村的建設(shè)以起獨(dú)特的濱海區(qū)位置成為撬動(dòng)濱海區(qū)城市空間更新的一枚楔子。

二、多元化的中心城區(qū)

既有城市的重組策略

圖3：在 "之前" 和 "之后" 的圖像之間， 我們可以區(qū)分城市層面的行動(dòng)和策略 (排污、運(yùn)輸、海濱、海港等)，這些是為局部或者區(qū)域的設(shè)計(jì)介入.前者往往是政府機(jī)構(gòu)的任務(wù)，而后者則可以與私人組織或公司進(jìn)行合作.Fig.3：Between the “before” and “after” images， we can distinguish the actions or strategies designed at city level (sewage， transport， seafront， harbor， …) and those designed for parts or districts.The former tends to be the task of government agencies， whereas the latter may be carried out in cooperation with a private organization or corporation.

城市的進(jìn)化改變了通信和生產(chǎn)系統(tǒng)，產(chǎn)生了更多空白空間。城市空間再利用得到極大的發(fā)展機(jī)遇。他們將被定位于一種宏觀的策略而不是某種特殊的措施。

圖4：當(dāng)前道路系統(tǒng) (紅色) 過(guò)去的道路系統(tǒng)(黑色)， 龍達(dá)環(huán)路主要在頭等級(jí)道路系統(tǒng)上進(jìn)行建設(shè)，要求對(duì)概念的重新思考避免城市障礙在許多城市中出現(xiàn)的如此普遍。Fig.4:The current road system (in red) was completed (in black)， mainly with the construction of the Ronda ring roads at the head of the road hierarchy called for a rethinking of the concept to avoid the urban barriers that are so common in many cities.

圖5：對(duì)角線大道旁的“利亞”是城中心最具代表的項(xiàng)目之一。它激活了一個(gè)城市中心被遺棄的地塊，營(yíng)造出一個(gè)新的“中心”。Fig.5:“L’Illa” as key example of an area of centrality along the Diagonal avenue.It recycled an abandoned site in the middle of the city.Mixed-use created a new “center”for the nearby communities.

完成緊湊化城市：再建虛空間

盡管恢復(fù)公共空間的策略十分重要,促進(jìn)城市重組經(jīng)濟(jì)結(jié)構(gòu), 創(chuàng)造新發(fā)展的要求也很重要。

城市重組戰(zhàn)略優(yōu)先考慮工業(yè)和商業(yè)活動(dòng)，包括基礎(chǔ)設(shè)施和公共交通：不利于中心城區(qū)和塞爾達(dá)擴(kuò)展區(qū)規(guī)劃的個(gè)體的交通活動(dòng)是城市內(nèi)最主要的運(yùn)營(yíng)負(fù)荷(圖4)。

因此，中心城區(qū)的重組一定是通過(guò)交通聯(lián)系來(lái)重建或者間隙空間。

首先，地鐵線路的擴(kuò)張、地面軌道交通的建造、公交線路網(wǎng)有效建設(shè)創(chuàng)造了社區(qū)之間的通達(dá)性。其次，城市外環(huán)的建成，雖然它作為最高級(jí)的城市快速道路系統(tǒng)，但是我們希望避免城市交通路線 生硬切割和隔離。因此，我們通過(guò)交通系統(tǒng)的等級(jí)化特征，劃分我們城市社區(qū)的出入口，這是一種常用的城市空間設(shè)計(jì)原理。

它可以提高公共交通和私人駕駛的可達(dá)性, 從而強(qiáng)化城市陳舊、閑置空間活力的可能,例如工業(yè)、港口和鐵路設(shè)施等地區(qū)。另外，新的中心城區(qū)提出建立公私合作的方式來(lái) 確保大部分投資能用于基礎(chǔ)設(shè)施工程。

這正是巴塞羅那推出的“新中心區(qū)”策略。曾經(jīng)被廢棄的工業(yè)和未使用的基礎(chǔ)設(shè)施占用的13處城市空地將被引入城市活動(dòng)。每一次的城市干預(yù)設(shè)計(jì)都具有規(guī)劃綱要，并將經(jīng)濟(jì)活動(dòng)融入了服務(wù)業(yè)、興建城市設(shè)施和公園，他們都將服務(wù)于當(dāng)?shù)鼐用駞^(qū)。

一個(gè)重要的案例就是坐落于對(duì)角線大道大道旁的“利亞”（圖5）。它修復(fù)了城市中間地區(qū)一處被遺棄的地塊，采取了綜合城市功能策略，將商場(chǎng)、公共服務(wù)、酒店和商務(wù)辦公區(qū)整合，另外提供了一處公園、兩所學(xué)校以及其他城市配套設(shè)施。當(dāng)以上這些城市功能匯集到一起，也就在周邊的數(shù)座社區(qū)之間創(chuàng)造出一個(gè)新的“中心”（圖6）。

三、老城的轉(zhuǎn)型

塞爾達(dá)的擴(kuò)展規(guī)劃和都市庭院

重回塞爾達(dá)擴(kuò)展規(guī)劃：從無(wú)人所知曉的社區(qū)到今天成功的鄰里空間范式(圖7)。

對(duì)塞爾達(dá)擴(kuò)展規(guī)劃的研究始于 1983年, 當(dāng)時(shí)將此區(qū)域定位為類似于美國(guó)城市中心的更新模式 , 其本質(zhì)是將城中心的庭院綜合利用和重新分類，從而為城市街區(qū)提供祥和的綠色公共空間。

在過(guò)去的40多年里塞爾達(dá)擴(kuò)展規(guī)劃建設(shè)形成于巴塞羅那的老城墻和城市外圍的村莊之間地帶。規(guī)劃師塞爾達(dá)在他自己的城市設(shè)計(jì)理論中闡述了網(wǎng)格原理(其雛形源于古典希臘、羅馬時(shí)代), 發(fā)表在他1859年的著作《城市建設(shè)理論》中, 其中他調(diào)查了很多城市（如波士頓、都靈、圣彼得堡和布宜諾斯艾利斯等）以及各種城市要素，注入歷史發(fā)展、氣候和地理等特征。塞爾達(dá)在他的家鄉(xiāng)巴塞羅那還調(diào)研了工人階級(jí)所處的非人性化、不健康的生活居住環(huán)境。在塞爾達(dá)規(guī)劃的擴(kuò)展區(qū)仙柏萊設(shè)計(jì)中找不到一處工廠。在滿足社會(huì)和經(jīng)濟(jì)需要的規(guī)劃設(shè)計(jì)后，他的希冀是創(chuàng)造一個(gè)健康生活的“全新的、偉大的” 城市。

塞爾達(dá)街區(qū)庭院是城中之“城”

塞爾達(dá)選擇了沿著外廓布置U 形三邊圍合, 而以一個(gè)不連續(xù)的低層建筑設(shè)置在第四條邊來(lái)滿足社會(huì)服務(wù)或公共用途, 意在圍合內(nèi)部 “庭院”, 卻又可保留從公共區(qū)域的自由進(jìn)出。

城市的發(fā)展導(dǎo)致了工業(yè)設(shè)施在塞爾達(dá)擴(kuò)展規(guī)劃中的建設(shè)，再加上大部分土地的私有化 特征，導(dǎo)致了后期大部分街區(qū)庭院被侵占。

不同的建筑法規(guī)默認(rèn)了這部分內(nèi)院空間的被侵占行為。然而， 人們認(rèn)為 , 城市是遵循外部街道以及家庭內(nèi)部活動(dòng)的結(jié)果，他是居住和生產(chǎn)活動(dòng)的相互聯(lián)系(圖8)。

圖8：這種城市形態(tài)的豐富性在于用途的疊加和類型的多樣性， 這在城市的臨街面得到了嚴(yán)格的表達(dá)，并且在城市街區(qū)庭院內(nèi)獲得了巨大的自由空間。Fig.8:The richness of this urban form lies in the superposition of uses and the typological diversity， which is rigorously expressed in the urban frontage and the great freedom within the city block.

塞爾達(dá)擴(kuò)展規(guī)劃的住宅再啟動(dòng)項(xiàng)目開(kāi)始于1980年代。在1985年,城市規(guī)劃法則明確街區(qū)庭院應(yīng)該是屬于公共活動(dòng)區(qū)域, 規(guī)劃當(dāng)局倡導(dǎo)能收回一些庭院作為公共空間, 并遵循原來(lái)的塞爾達(dá)擴(kuò)展區(qū)規(guī)劃的均質(zhì)化分割的邏輯。而后，新的規(guī)劃法則明確提出將擴(kuò)展區(qū)中心街區(qū)的內(nèi)庭院收回并開(kāi)放成為公共花園和綠色空間（圖9）。

圖9：圣安東尼圖書(shū)館以及內(nèi)部庭院作為開(kāi)放空間由2017年普利斯特獎(jiǎng)得主RCR設(shè)計(jì).在塞爾達(dá)的仙柏萊街區(qū)項(xiàng)目提議中，這個(gè)項(xiàng)目點(diǎn)是眾多存有爭(zhēng)議的案例之一，現(xiàn)在它終于獲得了對(duì)于1985年規(guī)劃提議的感謝和認(rèn)可.Fig.9:The Sant Antoni library and courtyard as open space designed by the 2017 Pritzker prize winners RCR architects.An example of those controversial elements proposed by Cerdà in his Eixample project which are now being reclaimed thanks to the 1985 plan.

四、老城區(qū)的改造

巴塞羅那的老城區(qū)

老城區(qū)是城市的起源地 , 某種意義上，近代塞爾達(dá)擴(kuò)展規(guī)劃延緩了老城區(qū)規(guī)劃改造（圖10）。直至20世紀(jì)80年代老城區(qū)才開(kāi)始內(nèi)部改造, 這也是當(dāng)時(shí)城市最鼓舞人心的城市項(xiàng)目。至今很少有人意識(shí)到這個(gè)項(xiàng)目所涉及的空前巨大的城市改建范圍，還有極具復(fù)雜的項(xiàng)目投資和管理工作。今天,老城區(qū)與眾不同的城市形態(tài)吸引了城市居民和世界游客的往來(lái), 這里發(fā)生的一切活動(dòng)都是全體市民所關(guān)注的話題。眾所皆知，它向我們印證了城市空間是隨著社會(huì)發(fā)展進(jìn)程不斷變化的過(guò)程。

老城區(qū)，歷史之城

回顧這座歷史名城, 就會(huì)發(fā)現(xiàn)它的城市遺存是多么的豐富和層次清晰: 古老的城墻, 周圍的市鎮(zhèn), 市集形成的街道……宗教或民用建筑, 以及梧桐蔓延的蘭布拉林蔭大道。

另外, 歷史城市和建筑空間的聯(lián)合創(chuàng)新，例如蒙特卡達(dá)街道上的斯托達(dá)·諾瓦新型的市鎮(zhèn)別墅、費(fèi)蘭和公主商業(yè)街道、新的紀(jì)念性廣場(chǎng)如圣豪梅和皇家廣場(chǎng)，還有隨后20世紀(jì)初期較大尺度的城市轉(zhuǎn)型，如萊耶塔納大街，鐵路建設(shè)和其他方面。

老城區(qū)的當(dāng)代價(jià)值

老城區(qū)在當(dāng)代的價(jià)值依然存在于他的建筑和城市空間。一方面，由于現(xiàn)實(shí)的復(fù)雜和矛盾，對(duì)城市公共或者集體空間的類型化研究將促進(jìn)理解城市形態(tài)的內(nèi)在價(jià)值。我們提出的批判性見(jiàn)解 來(lái)自于統(tǒng)計(jì)或者空間的分析;另一方面，城 市環(huán)境和紀(jì)念性空間不僅僅突出了豐富的藝 術(shù)紀(jì)念物程度，它作為歷史中的一員持續(xù)斷鞏 固著城市的客觀、抽象的文化尺度。

從這一角度來(lái)看 , 老城區(qū)過(guò)去二十年的城市復(fù)興過(guò)程是文化本質(zhì)的延續(xù)，至此巴塞羅那老城進(jìn)入最佳發(fā)展期和成熟期(圖11)。

五、新的都市區(qū)之路

綠色廊道重構(gòu)巴塞羅那都市區(qū)

巴塞羅那的轉(zhuǎn)型：公共空間為先導(dǎo)

城市設(shè)計(jì)項(xiàng)目將延伸到不同核心的鄰里區(qū)域，建造數(shù)座城市廣場(chǎng)和社區(qū)花園，這是城市設(shè)計(jì)項(xiàng)目的主要策略 ; 對(duì)集體生活空間的分享和討論將重新回到城市的規(guī)劃設(shè)計(jì)中。

廢棄的工業(yè)老區(qū)轉(zhuǎn)型成為城市公園(如克洛特區(qū) , 貝伽索 區(qū) , 西班牙工業(yè)區(qū))，它們是公共空間重 建的標(biāo)志。巴塞羅那城市周邊僅有少數(shù)幾座公園 , 因此 , 在都市區(qū)內(nèi)增加綠色空間的易達(dá)性成為一種 新需求。

這種現(xiàn)象被多數(shù)都市的中心城區(qū)模仿, 成為雄心 勃勃的城市復(fù)興戰(zhàn)略(圖12)。微自然、綠色空間理念在都市區(qū)中三十多座下轄區(qū)內(nèi)迅速擴(kuò)張。

與自然環(huán)境更好地融合

自然化的城市的街道、廣場(chǎng)和公園將通過(guò) 都市區(qū)的自然公園甚至農(nóng)田相連，組成一個(gè)新 的開(kāi)放的自然空間網(wǎng)絡(luò)，充滿生態(tài)潛力, 涵蓋休 閑和生產(chǎn)的可能性。自然環(huán)境和文明社會(huì)的網(wǎng) 絡(luò)都可以構(gòu)成都市區(qū)的骨干(圖13)。

都市區(qū)的開(kāi)放空間系統(tǒng)必須同時(shí)具有自然生態(tài)和城市景觀功能 , 并且必須建立在所有的尺度 上: 從大都市區(qū)到每一個(gè)構(gòu)成它的所屬地區(qū) ; 從 市民的活動(dòng)尺度到任何有助于生物多樣性的微觀 尺度。

環(huán)境的基質(zhì)是由山川、河流、溪水、沙灘以及農(nóng) 田等疊加而成，這些環(huán)境要素能在公共空間的體系上創(chuàng)造出不同的城市肌理，最終形成都市空間各個(gè) 組成部分。

物種間復(fù)雜的聯(lián)系組成了都市區(qū)的基質(zhì)。豐富、多樣化的都市綠色基礎(chǔ)設(shè)施具有自身特殊的管 理體系和模式。由于環(huán)境、社會(huì)和經(jīng)濟(jì)可持續(xù)性的 需求，新的都市區(qū)模式將被重新定義 :它將是保障 生物多樣性、維護(hù)生態(tài)活動(dòng)進(jìn)程 , 最有效的生態(tài)系 統(tǒng)。

都市區(qū)規(guī)劃中理解的綠色基礎(chǔ)設(shè)施，是維護(hù)和促進(jìn)使用或者建設(shè)多元的生態(tài)和社會(huì)生產(chǎn)，以及使之成為可能的實(shí)現(xiàn)多樣的生態(tài)、景觀和經(jīng)濟(jì)過(guò)程。

圖12：長(zhǎng)期來(lái)看大型綠地和公園具備生態(tài)承載條件，既有提供安靜空間能力，又具備生態(tài)、文化和經(jīng)濟(jì)活力。城市的去工業(yè)化背景下，工業(yè)用地轉(zhuǎn)型為城市公園。Fig.12: The green-belt and large parks provide capacity for resilience with a view to long-term adaptation to change and， in this way， achieve ecological， cultural and economic viability.The deindustrialization of cities offers new opportunities for transforming industrial land into urban parks.

圖13：綠色廊道策略將增加景觀基礎(chǔ)設(shè)施的易達(dá)性和連通性，從而取代傳統(tǒng)基礎(chǔ)設(shè)施的生硬空間，例如高速公路、城市干道和鐵路通常割裂城市空間形成城市屏障。新的綠色廊道將有助于建成的步行和自行車道。Fig.13: The green corridor strategy aims to increase accessibility and connectivity using the infrastructure of the landscape to replace heavy infrastructures such as roads， motorways and railway lines which used to act as barriers， breaking the city into pieces.The new green corridor will be very useful for structuring the landscape devoted to pedestrians and cyclists.

General framework

Barcelona can be considered as the prototype of a Mediterranean European city with a long urban tradition.With its over two thousand years of history, has played the role of capital of Catalonia.Cities in the south of Europe have quite specific formal characteristics and processes of historical formation: the density and compactness of their urban form and their evolution by means of extension rather than remodeling.

In 2012, Barcelona city had 1,620,943 inhabitants living in 98.21 square kilometers, and its metropolitan area had a population of 3.2 million in 636 square kilometers.Almost half the population of Catalonia lives in this area, which represents just 1.98% of the territory.

Barcelona is situated on a plain that slopes gently down towards the sea, delimited by the rivers Llobregat and Besòs and the coastal mountain range of Collserola, with its highest point of Tibidabo (512 meters)（Fig.1）.

The plain is a space of confluence for the inland prelittoral corridor that runs in a northsouth direction, and the coastline marks out a geographical system that has governed communication axes and modern urban expansion.As this article explains, today’s metropolitan space has overflowed this natural space and its everyday influence exceeds the limits of the province of Barcelona.

Strategies for dealing with the new urban culture

If we look at the spatial and physical components which are capable of channeling the different forms of intervention, we discover key themes and potential planning strategies.To these we could apply recent experiences of projects or research in which we have been involved.

The metropolitan dimension today: new spaces of opportunity

The restructuring of the eighties and nineties and the creation of areas of centrality paved the way, then, for completing a compact city between the rivers, where the fundamental structure was still the wide-ranging force of the Eixample grid, which offered itself as a continual, constant support, reinforced by the presence of outer ring roads for traffic.

In the metropolitan municipalities, we observe processes of redevelopment based on public spaces and parks that are generally larger than those in the central city, as they have more space.However, the matrix of intervention is municipal, many of the interventions being fairly autonomous.

Today, metropolises are subject to the pressures of phenomena derived from globalization that make financial and information systems move much faster than they used to,therefore affecting and unbalancing cities in very short periods of time.We tend to think that globalization is a standardizing force that makes all metropolises the same; however,this tendency has been found to produce very different results depending on the history and urban planning tradition of each city and its forms of governance.

It is not hard to see that we are facing new urban planning paradigms that call for new responses in city strategy and design.Today the metropolis is open and its parts are mutually related; the traditional city is too small and not sufficiently flexible, and we therefore have to structure the metropolis to make it minimally competitive.

The question arises today as to whether future strategies lie in the hard transformation of unproductive spaces in the compact city, or whether we have to see spaces of opportunity principally in the metropolitan space, perhaps woven together by other structures.

Because now we are discovering that development does not necessarily call for major physical growth, as it has done in previous decades; conversely, it is important to ensure the improved integration of social structure by means of what is known as inclusive development.

The interest of a metropolis today lies in being attractive and providing pleasant,efficient spaces for the people who live and work there, as well as offering areas with less pressure or control than the stabilized areas,because it is in these places that innovative interventions, different to traditional or existing initiatives, can be carried out.It will be in these “between” spaces or rather undefined situations that we find spaces of opportunity for certain types of new developments.

1.Waterfront as spin-off for the Metropolis

From the “Ribera Counter-Plan” to the“Olympic Waterfront”

Strategies that incorporate infrastructures and development while respecting their independence

The growing size of infrastructural developments in recent decades was taken imply a corresponding increase in the dimension of urban operations.The key is to accept the relative independence of the appropriate dimensions for infrastructural and urban developments.

Infrastructure projects have always been on a larger scale than other urban interventions, and this is still the case.However, the urban dimension of a project is not the same as its size.

As an example, we take the transformation of Barcelona’s waterfront using land formerly occupied by railway infrastructure.Among other things, the design had to accommodate a new beltway and facilities to connect the city’s drainage system to the Besòs sewage plant.This project naturally affected the coastline as a whole, because that was the dimension implied by its functions.A purely urban development, on the other hand, would call for a more fragmented di-mension, in accordance with the needs of the developers and the demands of the residents.The whole infrastructure of roads, sewerage and open space had to be provided first,whereas the seafront housing and commercial development was implemented in a series of operations at an intermediate scale, progressing to form five kilometers of coastal city.

Barcelona.The new “waterfront” in the Barcelona’s Olympic ’92 project

The “special” projects of the Olympic program for Barcelona 1992 were a bet for an internal development of the existing city,either through the valorization of empty or abandoned interstitial spaces, or of the construction of urban infrastructures - of communication and sanitation- necessary to link the different districts or sectors of the city（Fig.2）.

The 1992 Olympic program was proposed as a great urban reconversion project for the city.Within the urban continuum,seeking the articulation of empty interstitial areas, or provoking elements of rupture -like the triangle of the Olympic Village itself- that trigger a process of greater scope（Fig.3）.

The Olympic Village becomes a qualified reference for the process of urban transformation for Barcelona, due to its position as a wedge of progress towards the “waterfront”of the city.

2.Multiple urban centralities

ANC–Areas of New Centrality.New Downtowns

Strategies to restructure the existing city

The evolution of cities produces changes in systems of communication and production,leaving empty spaces.These offer exciting opportunities for ambitious strategies of re- uses.As far as possible, they should be addressed as general strategies rather than specific operations.

Completing the compact city: restructuring empty spaces

While the strategy chosen to recover public space is fundamental, the city also needs to restructure the economy and create thresholds for new developments.

This meant that strategies for industrial and commercial activity were a priority, along with infrastructure and public transport: the city was laboring under the pressure of individual mobility that was detrimental to the central city and the Eixample（Fig.4）.

In this context, it was considered vital to start work on restructuring means of transport to enhance the interstitial spaces.

Firstly, the extension of the Metro, the recovery of the tram and the rationalization of bus routes served to create links between the different communities.Then, the construction of the Ronda ring roads at the head of the road hierarchy called for a rethinking of the concept to avoid the urban barriers that are so common in many cities.A clear division between through traffic on a separate level and urban traffic, with access to the city and subject to the requirements of each urban sector,was introduced as the criterion for general design.

This increase in accessibility by public transport and private mobility served to enhance the city’s obsolete or empty spaces that had been deactivated, such as industrial,port and railway areas.A special program of new centralities served to establish mechanisms of public-private collaboration, ensuring that a large part of the capital gains generated were invested in general infrastructures pending construction.

This was the case in Barcelona and the strategy to promote “new centralities” in its urban area.Thirteen areas of wasteland,occupied by obsolete industry or unused infrastructure, provided an opportunity to introduce central activities into areas that would otherwise remained peripheral in character.Each intervention had a specific brief, and economic activity was joined by services, facilities and parks that could benefit the existing residential sectors.

One key example among the selected areas was “L’Illa” along the Diagonal avenue（Fig.5）.It recycled an abandoned site in the middle of the city.Mixed-use program with shops, services, hotel and offices complemented a park, two schools and other facilities.All together created a new “center”for the nearby communities（Fig.6）.

圖6：新商業(yè)區(qū)策略計(jì)劃重塑城市的閑置空間Fig.6:The New Downtowns strategy plan to re-structure the empty spaces of the city.

3.Transforming the downtown

Eixample Cerdà and the courtyards

The recovery of the Eixample: Today a celebrated neighborhood, at that time little known to residents.Enhancing a “great project” of the city（Fig.7）

圖7：塞爾達(dá)的 仙柏萊街區(qū)項(xiàng)目的力量在于將一個(gè)普通的城市幾乎無(wú)限延伸地穿過(guò)空巴塞羅那平原， 為一切提供了空間。Fig.7:The force of Cerdà's Eixample project lay in the idea of a regular city extending almost infinitely across the empty Barcelona Plain， where there was room for everything.

Research into the qualities of the Eixample started in 1983 in view of the transformation that was turning it into a US downtown,a central office monoculture, addressed its intrinsic values and the possibilities of conversion with mixed uses and a reclassification of the courtyards at the center of the city blocks as quiet, green spaces.

The Eixample was realized during a period just exceeding forty years on a disused terrain between the old, walled town of Barcelona and the surrounding villages.Cerdà elaborated the grid principle (originally conceived of in classical Greco-Roman times) in his own theory of urban design, published in his book “Teoría de la construcción de las ciudades /Theory of City Construction” (1859), in which he investigated numerous aspects of cities, such as the historical development and climatological and geological characteristics of such cities as Boston, Turin, St Petersburg and Buenos Aires.In his home town of Barcelona, Cerdà studied the inhumane and unhealthy living conditions of the working class.No modern factories are to be found in Cerdà’s design for the Eixample; his ambition was to create a “new and great” city, without impediments to a healthy life, and it was for this reason that the expansion plans took explicit account of both economic and social needs.

The interior courtyards are “cities” inside the city

Cerdà opted for a U-shaped layout of the building following the perimeter of the block,with a discontinuous and low construction on one side–for services or public use–with the intention of outlining the interior “courtyard”but retaining access from the public space.

The development of the project addressed industrial use in the Eixample and the intention to maximize private land management, questions that led to the occupation of the majority of the courtyards in the blocks.

Different building regulations consolidated these options and fixed the volumes that were allowed in each moment of their application.In conclusion, one can say that the city has developed following the street and a more domestic interior world that is related to residential uses and productive activity（Fig.8）.

The residential recovery of the Eixample has continued apace since the eighties.In 1985, plans were set in train to reclaim some of the courtyards as public spaces,continuing the logic of a homogeneous distribution, but also considering blocks where it was more feasible for this to be done.Moreover, it restricted building in the very center of the blocks, making it possible to develop gardens and green areas in their courtyards（Fig.9）.

4.Retrofitting the Old Town of Barcelona

Barcelona’s Old Town

Ciutat Vella is a seminal space in the formation of the city, where improvement work had been postponed due to the success of the Eixample（Fig.10）.The internal remodeling of Ciutat Vella, started in the 1980s, has been one of the city government’s most ambitious projects, alongside the Olympic Games.Few people are aware of the huge and quite unprecedented scope of investment and management involved.Today, Ciutat Vella has a different profile; it attracts city residents and tourists alike, which is becoming an issue of concern for local residents.As we know, the city is a process of constant transformation and a social process that requires constant and careful monitoring.

圖10：資本家建造了仙柏萊城市擴(kuò)展的居住區(qū)，也是創(chuàng)新型的城市投資區(qū)；中產(chǎn)階層和工人階級(jí)在擴(kuò)展區(qū)的格網(wǎng)規(guī)劃中都有一席之地。老城成為當(dāng)時(shí)衛(wèi)生條件欠缺的舊城區(qū)。直至20世紀(jì)80年代，由于奧運(yùn)會(huì)契機(jī)才成為當(dāng)時(shí)市政府最富雄心的城市改造項(xiàng)目。Fig10:The bourgeois found in the Eixample the place of its residence and its most innovative investments; the middle classes followed their lead and even the working classes had their space in the Eixample grid.Ciutat Vella became a rather residual place， reaching levels with no regard for hygienist logic.Till 1980s， when it became one of the city government’s most ambitious refurbish projects， alongside the Olympic Games.

Ciutat Vella, the city throughout history

A look at the long-term construction of the historic city shows just how rich and gradual its materialization has been: town walls,surrounding boroughs, streets organized by trades, religious or civil buildings with great spatial presence, the continuous adjustment of the Rambla, and so on.

We also see how the historic city incorporated innovation, coinciding with the appearance of new forms of residence, such as the town houses in Carrer Montcada, like the Strada Nuova, and new kinds of commercial streets such as Ferran and Princesa, new calls for monumental plazas like Sant Jaume and Pla?a Reial,and later and perhaps less careful large-scale transformations in the context of the twentieth century, such as Via Laietana, the construction of the Metro, and many others.

The contemporary values of Ciutat Vella

We can understand the current values of Ciutat Vella by studying its buildings and urban spaces.The classifying effort of the types and the public and / or collective spaces allows us to understand the intrinsic values of urban forms, the reading to which often escapes because its complexity and controversy.Probably an effort to objectify values,even statistical or spatial, is essential to enrich our critical knowledge and helps taking the best decisions.On the other hand, progress in representing these environmental and monumental variables allows us to understand not only the richness of the artistic monuments, but also the historical ones, and in this process, to consolidate the objective and transcendental dimensions of this singular urban legacy.

In this perspective, the rehabilitation process of the last twenty years can be seen as the resumption of an essential activity from which the best development and maturation time for the Ciutat Vella is opened（Fig.11）.

5.New Metropolitan approach

Area Metropolitan of Barcelona, Green Corridors to restructure the Metropolis.

The transformation of Barcelona: public space as a priority

An extensive program of constructing squares and gardens was centered on strategic places, at the heart of different neighborhoods;collective life returned to the forefront and careful spatial design was shared and discussed in the city:a paradigm changed in city construction.

The transformation of abandoned industrial installations (El Clot, Pegaso, Espa?a Industrial) into urban parks was an important sign of change.Barcelona is a city of few parks that tend to be situated around its edges, so accessibility to green space became an attraction and a new demand.

This phenomenon driving the central city was replicated in most of the metropolitan municipalities, becoming a more ambitious strategy（Fig.12）.The idea of a miniature central city in thirty or so metropolitan municipalities spread fast.

圖11：長(zhǎng)期的歷史城區(qū)建設(shè)呈現(xiàn)了豐富和多層的物質(zhì)空間形態(tài)，就像記載城市歷史的古老的羊皮紙：呈現(xiàn)著城市類型化的描述和片段；城市歷史形態(tài)學(xué)的體系，以及最近150年以來(lái)城市轉(zhuǎn)型的疊加。Fig.11: The long-term construction of the historic city shows just how rich and gradual its materialization has been， like a great urban palimpsest.Typological description and fragment; morphological systems throughout history， and superposition of transformations in the last 150 years.

Creating better integration with the NATURAL ENVIRONMENT

The streets, squares and parks of our cities can re-naturalize themselves and connect with metropolitan parks as well as with the agricultural and natural areas that still remain.A new network of open spaces that will have all possible connectivities and be full of ecological potential, possibilities for leisure and productive capacities.An environmental and social network constituting one of the backbones of the metropolis（Fig.13）.

The system of open spaces in the metropolis must, simultaneously, have ecological and landscape functionality, and must be built on all scales: from the metropolitan to the urban scale of each one of the cities that comprise it; from the human scale of its citizens to the microscopic scale of anything that may contribute to the enhancement of biodiversity.

It is the intentional superimposition of the environmental matrix formed by mountains, rivers, streams, beaches and agricultural spaces on the systems of public spaces that can be created within the different urban fabrics that make up the metropolis.

The complex relationships between species make up the territorial matrix.There is a rich and varied green metropolitan infrastructure with its own specific management bodies and models.A new metropolitan paradigm towards environmental, social and economic sustainability needs to be defined which ensures biodiversity and the maintenance of ecological processes, maximizes ecosystem services and regulates any disturbance.

Green infrastructures in the metropolis can only be explained from the maintenance and promotion of the different ecological and social flows that use or build them, as well as from the different ecological, landscape and economic processes that make them possible.