【正文】 設(shè)施不具有經(jīng)濟(jì)競(jìng)爭(zhēng)力，因此在考慮建造前必須在美學(xué)，環(huán)境或者是社會(huì)效應(yīng)方面給予綜合評(píng)估，除非是一些有特殊標(biāo)志性意義的設(shè)施否則將 會(huì)造成現(xiàn)階段國(guó)家無法承擔(dān)或是很勉強(qiáng)承擔(dān)的奢侈浪費(fèi)。不幸的是，在世界范圍內(nèi)，靠公眾權(quán)力來開發(fā)近地表空間已經(jīng)太遲了。 。 。在東京，新的 KeiyoJR 線深達(dá) 40m。 環(huán)境利益 另一個(gè)利用地下空間的主要策略是全球日益增長(zhǎng)的對(duì)環(huán)境問題的關(guān)注，并導(dǎo)致人們重新考慮城市的將來和工業(yè)的發(fā)展。地下設(shè)施以其自身特點(diǎn)成為一種典型的儲(chǔ)能設(shè)施。作為更佳細(xì)致規(guī)劃和研究的補(bǔ)充，未來的規(guī)劃者和設(shè)計(jì)者已提出對(duì)大范圍地下結(jié)構(gòu)甚至從整個(gè)城市的角度綜合考核，將是非常有用的。這一點(diǎn)不僅緩解了堵塞而且提供了更加有效的能源衍生和廢物循環(huán)。在這種情況下，地球上的地下城市略不同于以月球或其他孤立環(huán)境為基礎(chǔ)創(chuàng)建的城市。 高層建筑的豎向構(gòu)件從上到下逐層對(duì)累積的重力和荷載進(jìn)行傳遞，這就要有較大尺寸的墻體或者柱體來進(jìn)行承載。地震荷載的效應(yīng)更為明顯。 不幸的是，對(duì)于高層建筑首先要解決的不僅僅是抗剪問題，還有抵抗力矩和抵抗變形問題。用于抵抗側(cè)向荷載的材料要求更多。在地震荷載作用下，頂部質(zhì)量的增加將會(huì)使側(cè)向荷載劇增。但是必須保證加寬后的豎向承重構(gòu)件非常有效地連接。例如，增加較低層柱以及連接大梁的翼緣截面，將可直接減少側(cè)向位移和增加抗彎能力，而不會(huì)加大上層樓面的質(zhì)量，否則，地震問題將更加嚴(yán)重。但僅僅通過豎向構(gòu)件進(jìn)行抗剪是不經(jīng)濟(jì)的，因?yàn)槭怪傲河凶銐虻目箯澞芰?，比用墻或斜撐需要更多材料和施工工作量? 應(yīng)當(dāng)注意的是，所有高層建筑的本質(zhì)都是地面支撐的懸臂結(jié)構(gòu)。例如，住宅樓需要很多隔墻，如果這 些隔墻都設(shè)計(jì)為實(shí)例的，那么他們可以起到剪力墻的作用，既能抵抗側(cè)向荷載，又能承受豎向荷載。因此有必要經(jīng)常在兩個(gè)相互垂直的方向設(shè)置剪力墻，或者在盡可能多的方向布置，以用來抵抗各個(gè)方向的側(cè)向荷載。如果所有外部剪力墻都連接起來，整個(gè)建筑物就像是一個(gè)筒體，將會(huì)具有很強(qiáng)的抵抗水平荷載和抵抗扭矩的能力。從強(qiáng)度和變形控制角度來說，桁架有著很好的功效，并且管道可以在構(gòu)件之間穿過。不過在這樣的結(jié)構(gòu)設(shè)計(jì)中存在的問題是，如何保證在門洞口和其他孔洞的強(qiáng)度。還要求由這些結(jié)構(gòu)分體系提供的剛度在各個(gè)方向上應(yīng)大體對(duì)稱。同時(shí)它還能充分利用建筑物內(nèi)在任何情況下都要采用的梁和柱的剛度，但當(dāng)柱子與梁剛性連接時(shí)，通過框架受彎來抵抗水平和豎向荷載會(huì)使這些柱子的承載能力變得更大。因此，框架結(jié)構(gòu)常被視為最好的高層抗震結(jié)構(gòu)。如果在混凝土框架設(shè)計(jì)時(shí)不進(jìn)行特殊的延性設(shè)計(jì)，那么他將很難承受比設(shè)計(jì)標(biāo)準(zhǔn)值大很多倍的地震荷載的沖擊。然而，這些規(guī)范往往要求在框架的某 處增設(shè)過多的鋼筋，這就增加了施工的難度。 結(jié)論 以上所述就是高層建筑最普通的結(jié)構(gòu)形式。 and growing concern for the maintenance and improvement of the environment, especially regarding global warming and the impact of population growth. Underground space utilization, as this chapter describes, offers opportunities for helping address these trends. By moving certain facilities and function underground, surface land in urban areas can be used more effectively , thus freeing space for agricultural and recreational purpose. Similarly, the use of terraced earth sheltered housing. Using underground space also enables humans to live more fortably in densely populated areas while improving the quality of live. On an urban or local level, the use of underground facilities is rising to acmodate the plex demands of today`s society while improving the environment . For example, both urban and rural areas are requiring improved transportation, utility, and recreational services. The state of traffic congestion in many urban areas of the world is at a critical level for the support of basic human living, and it is difficult if not impossible to add new infrastructure at ground level without causing an unacceptable deterioration of the surface environment or an unacceptable relocation of existing land uses and neighborhoods. On a national level in countries around the world, global trends are causing the creation and extension of mining developments and oil or gas recovery at greater depths and in more inaccessible or sensitive locations. Three trends have also led to the developments of improved designs for energy generation and storage systems as well as national facilities for dealing with hazardous waste (including chemical, biological, and radioactive waste ), and improved highspeed national transportation systems .All these developments involve use of the underground . Land Use Pressures Placing facilities underground is a promising method for helping ease land use pressures caused by the growth and urbanization of the world`s population. Although the average population density in the world is not large, the distribution of population is very uneven. A map of population density in the world is not large ,areas of the world are essentially uninhabited . These areas are for the most part deserts ,mountainous regions, or regions of severe cold that do not easily support human habitation. If one examines China ,for example ,the average population density is approximately 100 persons per square kilometer, but the vat majority of the one billionplus population lives on less than 20 percent of the land area. this is the fertile land that can support food production. However, due to population growth, urbanization, and economic growth, this same land must now support extensive transportation systems, industrial and mercial development, and increasing demands for housing, As the population and economy grow, the land available for agriculture shrinks, and the problems of transporting food and raw materials to an urban population increase. By the year 2020 it is estimated that 70 percent of the world`s population will inhabit urban areas. The same trend are evident in Japan, where approximately 80 percent of the land area is mountainous,90 percent of the population lives on the coastal plains, and economic development is concentrated in relatively few economic development is concentrated in relatively few economic centers .The flatlying land is generally the most fertile and is historically the region of settlement . Other factors adding to population density include the traditional building style , which is lowrise , and Japanese law that contain strong provisions for maintenance of access to sunlight .Also ,to retain domestic food production capability , the Japanese government has protected agricultural land from development. The bination of these historical and political factors together with a strong migration of businesses and individuals to the economic centers has created enormous land use pressure. The result is an astronomically high cost of land in city centers (as high as US $500,00 per square meter) and difficulty in an providing housing, transportation, and utility services for the population. Typical business employees cannot afford to live near the city center where they work and may have to mute one to two hours each way from an affordable area. To service the expanding metropolitan area, public agencies must upgrade roads and build new transit lines and utilizes. Land costs for such work are so high that in central Tokyo, the cost of land may represent over 95 percent of the total cost of a project. The problem of land use pressures and related economi