The diaphragm wall of top down construction not only supports the horizontal loads at stage of the temporary construction , but also bears vertical loads , as a part of the main structure , the outer wail of the basement 逆作法施工中的地下连续墙不仅在施工时起临时支护作用，承受水平荷载，而且可直接作为地下室的外墙，并承担一定的竖向荷载。
Based on the present situation of top down construction for underground engineerings , the author illustrated the advantages , disadvantages and technology of top down construction and analyzed some key problems for top down construction 本文结合地下工程中逆作法施工的发展现状，介绍了逆作法施工的优缺点及其施工工艺，并针对逆作法施工中的几项关键环节，进行了详细的分析和研究。
And the author also put forward several proposals about top down construction in the paper , as well as summarized and advanced the developing trend of top down construction and the problems which should be made gret efflorts to solve 文章最后结合具体工程实践，对逆作法施工工艺的具体应用进行了介绍，详细说明了逆作法的效果。文章还总结并提出了逆作法在我国的发展趋势及应努力解决的问题。
Anchor jacked pile is a new technique researched by ourselves for building reinforce and has some strongpoint others have not . twenty years " popularization makes this technique widely used . now anchor jacked pile can be applied in some other project such as correction , ground strengthening , pile foundation ' s top - down construction in newly built building 锚杆静压桩作为我国自行研制的一种地基托换加固新技术，有着其它施工方法所不具有的自身的优点，经过二十年的推广使用，目前在很多地区已经广泛使用，而且其适用范围也从以前的单一的托换加固作用发展成可用于纠偏、补强加固、新建工程逆作法桩基施工等工程。
The center brace , also named guide pillar , serves a dual purpose , not only surpporting all the loads at stage of construction , but also transmitting upper loads down to the foundation , as a part of the column after the top down construction , its designing and construction are more strict 中间支承柱又称导柱，在逆作施工中起着双重作用，既要支承逆作法施工中的各种荷载，又要在逆作法完工后，作为主体柱子的一部分，起着将上部荷载传递给基础的作用，因而设计与施工均对其提出了较高的要求。
The rule of loads and settlement is concluded from numbers of settlement observation points ’ data . and in actual construction , this rule could be used to prevent immediate settlement under the accelerated load , and also , the serious result of the soil destruction could be avoided . at last , a proper method of settlement computing is derived from the identified rules , which can be used to guide the practical construction work , of course , meeting the compulsory standards of the settlement control well 采用逆作法施工,现实地解决了桩、土与筏板接触面的变形协调关系;通过对桩、土受荷过程的实际测试,得出了桩、土分担荷载比例和变化过程,从而为桩、土的荷载计算提供实际依据;从设置的大量沉降观测点中所得到的沉降资料,得出荷载、沉降变化规律,从而指导在实际施工中,防止加载过快而导致速沉,避免由此带来的土体破坏的严重后果;通过沉降规律分析,得出了适用于软土地区的桩基沉降计算方法,用于指导实际施工,以满足沉降控制的强制性标准。
Researching on the technology if reverse order is to study strains if pits , structural systems if basement , environmental surwey and underpinnings . on account of emphasizing developing methods if checking strength if pick - ets , modemizing machenes of excavation and studying methods of underpinning is put forward and is a way if controlling the quality of pickets in sites , which leads an active effect ; synthetic application if rankintheory , spatial and time effect theory to excavation tl aanalyze the state of soil force and strain is brought forward and the time effect should be considered in the zone of clay , the formation and development of soil plasticity are analyzed and the most dangerous zone to decide how to excavate and where to begin is found ; analyzing the cause of picket settlement during reverse order and the differential settlement and discussing hlw to solute it . duringh the temporary survey and the environmental warship , bringing rorward the theory of environmental vibration and analyzing the state of soil force and probability of losing stabilization of soil under the effect of environmental vibration ; analyzing the state offeree in underground concrete wall by the method of mathematics and pointing out the place of the maximum force and deformation . based on systematic illustrating the reverse order , problems about application and development of reverse order and suggestions also are expressed 鉴于国内外的研究把重点放在大力发展工程桩的实验室承载力监测方法与设备、如何使土方开挖机械现代化及对周围建筑的临测方法上，本文提出了现场利用声波层析成像技术监测钢砼桩内部质量的方法与程序，并得出了声波层析成像技术是砼桩的动态质量检测的有效手段，这对指导施有积极、现实意义；提出了综合运用朗肯土压力理论、基坑空间和时间效应影响理论来分析逆作法施工过程中基坑边坡土体应力及应变的变化情况，指出粘土地区也应考虑时间效应，并且进一步分析了基坑边坡土体的塑性区形成和发展，找出边坡最不利的区域，以确定地下室土体的挖掘的方式和顺序，指出凭主观臆断与经验来施工是不可取的；在分析、经较逆作法与大开挖顺作法的地下室结构体系受力情况及施工顺序的不同，提出了节点处理技术；分析了逆作法施工期间桩的沉降变化原因及由此而产生的差异，并探讨了解决的方法；本文还提出了环境振动对土体边坡稳定产生影响的观点，并分析了在环境振动影响下，土体的应力状态及土休失稳破坏概率，并且还运用弹性力学知识和数学分析的方法定量地分析了地下混凝土墙受力状态，指出了被监测墙体的最大应力、应变位置。
Bing top down construction is carried out , the underground structure construction , including soil engineering , concrete casting and formwork , becomes more complicated and more strict . the paper gives a detailed research on the problems , and brings forward corresponding solutions . the monitor of the deep pit is also the important problem to the top down construction 地下室主体结构也因采用逆作法施工，使土方工程、砼逆作浇筑、模板工程等变得更为复杂，要求也更加严格，本文对地下室主体结构施工中的有关问题进行了较为详细的研究，提出了相应的解决措施。
Based on the central - island and athwart construction method for excavation of large foundation pit of shanghai south railway station of south square in soft soil , the active mechanism of remain mound was analyzed ; the deformation of underground diaphragm wall under the condition of three different remained mound width with or without consolidation was contrasted through centrifuge model test , the effect of remained mound width with or without consolidated on the deformation of diaphragm wall was acquired ; then the deformation of underground diaphragm wall with several different widths of mound was calculated by fem , finally it was presented that the reasonable mound width could be determined according to the diminishing ratio of deformation 摘要以铁路上海南站南广场大型软土基坑采用中心岛结合预留土台逆作法施工为背景，分析了预留土台的作用机理：通过离心模型试验对比研究三种不同土台预留宽度及其加固与否对地下连续墙的变形控制作用，得出了土台预留宽度及土台加固与否对连续墙变形的影响规律；在此基础上，采用有限元模拟计算多组土台宽度下地下连续墙的变形，得出了根据变形减小率来确定合理的土台预留宽度。
