历史建筑的“浴火重生”

嘉兴老火车站的结构涅槃

TJAD4结构所

设计单位： 同济大学建筑设计研究院（集团）有限公司

项目地址：浙江省嘉兴市

项目年份：2019~2021年

建筑面积：2500平方米

结构体系：砖木结构+钢木屋架混合结构

01  

历史建筑修缮及更新之痛

The Pain of Restoration and Renewal of Historic Buildings

历史建筑是一 座城市的记忆。它是城市的“历史记忆符号”和“城市文化发展的链条”。历史建筑的修缮与更新设计工作由于其自身的特殊性，与一般的现代建设工程设计工作有着明显的区别。首先是对象特殊：一般建设工程是在空余的场地上进行建设，修缮工程则是对已经存在的建筑进行保护。其次，价值取向不同：一般的建设工程的目标是建设新的建筑，其重视的是所建成建筑的使用价值。而历史建筑的修缮工程因其工程对象的特殊性，注重的是其蕴含的文物价值。第三，存在一定的复杂性：具体表现在两个方面，一是历史建筑结构体系的复杂性，二为使用过程中私搭乱建问题严重。第四，具有不可控性：实际工作中，由于古建筑常有许多隐蔽部位，许多构件需要拆卸，并完全暴露后才能 全面检查，设计时不可预见因素较多。综上所述，对于历史建筑的结构修缮是一项细致入微的工作，需要抽丝剥茧的弄清楚建筑的结构体系，使用过程中的改建做法，从而提出完整的结构修缮做法，既满足建筑修缮的要求，也需要一定程度提高原结构的安全性能。

Historical architecture is the memory of a city. It is the city's "historical memory symbol " and "the chain of urban cultural development " . Due to its own particularity, the repair and renewal design of historical buildings is obviously different from the general modern construction engineering design . The first is the special object : general construction projects are carried out on vacant sites, while repair projects are to protect existing buildings. Secondly, the value orientation is different : the goal of general construction projects is to build new buildings, which pays attention to the use value of the built buildings. However, due to the particularity of the project object, the restoration project of the historical building pays attention to the cultural relic value contained in it. Third, there is a certain degree of complexity : it is manifested in two aspects, one is the complexity of the historical building structure system , and the other is the serious problem of private building and disorderly construction in the process of use. Fourth, it is uncontrollable : In actual work, because ancient buildings often have many hidden parts, many components need to be disassembled and fully exposed before comprehensive inspection. There are many unforeseen factors in the design . To sum up, the structural repair of historical buildings is a meticulous work. It is necessary to figure out the structural system of the building and the reconstruction method during the use process, so as to propose a complete structural repair method, which not only meets the requirements of building repair , but also improves the safety performance of the original structure to a certain extent.

02  

嘉兴老火车站历史演变及改造修缮策略

Historical Evolution and Renovation Strategy of Jiaxing Old Railway Station

嘉兴老火车站位于嘉兴市火车站片区，位于2021年重走一大路的红色旅游线上，主体建筑为嘉兴市文物保护单位。现存的嘉兴老火车站为1940年侵华日军修建，在后续的使用过程中不断的加建与改建，原候车大厅改建为办公，在既有建筑的北侧加建了一层或二层的小楼。

Jiaxing Old Railway Station is located in the railway station area of Jiaxing City, on the red tourist line that has taken a big road again in 2021. The main building is a cultural relics protection unit in Jiaxing City. The existing Jiaxing old railway station was built by the Japanese invaders in 1940. During the subsequent use, it was continuously added and reconstructed. The original waiting hall was converted into an office, and a small building with one or two floors was added to the north of the existing building.

“重走一大路”平面示意图

The plan of "Retake one Road"

不同时期嘉兴老火车站外观

Appearance of jiaxing old railway station in different periods

嘉兴老火车站建筑体块和功能演变图

Building block and function evolution of Jiaxing old Railway Station

改造策略主要可分为三部分。第一部分为“拆”，将后期搭建或加建的影响历史建筑原历史信息的部分进行拆除。第二部分为“修”，将历史建筑进行修缮，建筑外立面恢复原有历史风貌，内部恢复原有建筑结构形式。第三部分为“更新”，对于历史建筑内部及后期加建部分进行更新处理，展现历史演变痕迹与建筑使用功能要求。

The transformation strategy can be divided into three parts. The first part is "demolition " , which is to demolish the part of the later construction or addition that affects the original historical information of the historical building. The second part is "repair " , which repairs the historical buildings, restores the original historical features on the facade of the building, and restores the original architectural form inside . The third part is "renewal", which updates the interior and later additional parts of the historical building to show the traces of historical evolution and the functional requirements of the building.

建筑修缮与改造策略示意图

Schematic diagram of building repair and renovation strategy

03  

“浴火”—加建部分的拆除

"Bathing Fire " - Demolition of the Addition

嘉兴老火车站在明确修缮及重建策略后，它所经历的第一步就是“浴火”即“拆除原建筑使用过程中私搭乱建的各种结构与非结构构件”。在拆除过程中，结构团队给出了详细的拆除范围，同时指定拆除的方法，明确拆除的顺序，同时，施工单位编制了拆除专项的施工组织方案。确保拆除过程避免对原结构承重构件的损伤，同时保持建筑中的历史痕迹。

After clarifying the repair and reconstruction strategy of Jiaxing old railway station, the first step it has experienced is "bathing fire", that is, "demolish all kinds of structural and non-structural components that were arbitrarily constructed during the use of the original building". In the process of demolition, the structure team gave a detailed scope of demolition, specified the demolition method and clarified the demolition sequence. At the same time , the construction unit prepared a special construction organization plan for demolition. Ensure that the demolition process avoids damage to the load-bearing elements of the original structure, while preserving the historical traces in the building.

拆除范围示意图 

Schematic diagram of the demolition area

楼板拆除

 

屋面拆除

 

后搭建部分拆除

04  

“重生”—既有历史建筑部分的修缮

"Rebirth " - Restoration of existing historic buildings

嘉兴老火车站经历过“浴火”的洗礼之后迎接的就是“重生”，而“重生”分为两块，其中一块为历史保护建筑部分的修缮与改造。

After experiencing the baptism of "bath fire", Jiaxing old railway station welcomes "rebirth", which is divided into two parts, one of which is the repair and transformation of historical protection buildings.

嘉兴老火车站的历史文保部分在后期的使用过程中承重构件出现了多处损伤，主要为（1）既有木屋架中木构件的干缩裂缝；（2）木屋架中出现脱榫现象，个别木构件出现受力性裂缝；（3）承重墙体出现非受力性贯穿性裂缝。

In the later use of the historical cultural protection part of Jiaxing old railway station, many damage occurred to the load-bearing components, mainly as follows: (1) dry shrinkage cracks of wood components in the existing wooden roof truss;(2) The tenon phenomenon occurs in the wooden frame, and some wooden members have stress cracks;(3) Non stress penetrating cracks appear in the load-bearing wall.

本项目中木屋架中木构件的干缩裂缝，采用用木条和环氧树脂胶，将缝隙嵌补粘结严实。当构件的裂缝深度超过梁宽或梁直径的1/4时，则更换构件。木屋架中脱榫采用下列修复方法：当榫头完整，仅因倾斜而脱榫时，可将屋架拨正，再用铁件拉结榫卯。当出现榫头糟朽、断裂而脱榫时，应先将破损部分剔除干净，并在构件端部开卯口，经防腐处理后，用新制的硬木榫头嵌入卯口内，嵌接时，榫头与原构件用环氧树脂胶粘牢并用螺栓固紧。在嵌接长度内用两道铁箍箍紧。内部因糟朽中空截面面积不超过全截面面积1/3 时，可采用氧树脂胶灌注加固。对于木屋架中构件出现断裂情况，本项目采用外衬钢板的办法进行加固。

In this project, wood strips and epoxy resin glue are used to fix and bond the dry shrinkage cracks of wood structure in the wooden frame. When the crack depth of the member exceeds 1/4 of the beam width or beam diameter , replace the member. The following repair methods are adopted for tenoning in the wooden roof truss: when the tenon is complete and the mortise is only removed due to inclination, the roof truss can be adjusted, and then the mortise and tenon can be tied with iron pieces. When the tenon is decayed, broken and the tenon is removed, the damaged part should be removed first, and a mortise should be opened at the end of the component. After anti-corrosion treatment, a new hardwood tenon should be inserted into the mortise. The components are glued with epoxy and fastened with bolts. Fasten with two iron hoops within the inlaid length. When the internal hollow cross-sectional area does not exceed 1/3 of the full cross-sectional area due to decay, oxygen resin glue can be used for reinforcement. For the fracture of the components in the wooden roof truss, this project adopts the method of outer lining steel plate for reinforcement.

对于砌体墙体裂缝修补主要采用以下几种方式进行修缮，见表1。

The following methods are mainly used to repair the cracks of masonry wall, as shown in Table 1.

表 1 墙体 裂缝修补方法

砌体裂缝     情况	修补方法
裂缝     宽度小于     0.5     mm ，且裂缝深度较浅	填缝法
裂缝     宽度     大     于     0.5     mm ，且裂缝深度较     大	压力     灌浆法
裂缝     有发展趋势，且     砌块     及砂浆强度等级低，有风化、剥落情况	填缝法 / 压力     灌浆法     + 外加     钢丝     网片     法
承重     墙体，局部墙体破坏严重	局部     置换法     + 外加钢筋网砂浆面层     法
自承重     墙     体，     且     砌块     及砂浆强度等级低	局部     置换法

 

   

木屋架端部裂缝修缮做法及现场修缮照片

Repair method of cracks at the end of wooden frame and photos of on-site repair

墙体破损修缮前后情况

Condition of damaged wall before and after repair

05  

“重生”—既有历史建筑部分的更新

"Rebirth " - Renewal of existing historic buildings

根据建筑需求，嘉兴老火车站中既有历史建筑部分需要进行局部改建。其中变化最大的为原大厅内需要新增一个观景平台，需要将该区域搭建的混凝土楼板部分拆除，形成了高度达到10m的砌体墙。针对本项目自身的结构特点，结构利用建筑需要新增观景平台的要求，在既有墙体四角及侧壁部分新建混凝土梁柱体系。通过上述方法既保证历史文保建筑的整体性，满足建筑功能需求，同时也提高其整体的抗震性能。

According to architectural requirements, the existing historical buildings in Jiaxing Old Railway Station need to be partially reconstructed. The biggest change is that a viewing platform needs to be added in the original hall, and the concrete floor slab built in this area needs to be removed, forming a masonry wall with a height of 10m. According to the structural characteristics of the project itself, the structural utilization building needs to add a viewing platform, and a concrete beam-column system is built at the four corners and side walls of the existing wall. The above method not only ensures the integrity of the historical cultural protection building, meets the functional requirements of the building, but also improves its overall seismic performance.

候车大厅改造效果图

Effect drawing of transformation of waiting hall

候车大厅内改造加固平面示意图

Schematic diagram of the renovation and reinforcement in the waiting hall

新增混凝土梁与既有砌体墙拉结做法

New concrete beam and existing masonry wall tensile method

新增混凝土柱与砖既有砌体墙拉结做法

Construction method of new concrete column and existing brick masonry wall

06  

“重生”—后期加建部分的更新

"Rebirth " - Updates to late additions

针对70年代搭建的部分，建筑考虑既要保留历史痕迹，又要满足新的建筑功能和外观。为此，结构采用“旧瓶 装新酒”的处理方法，保留原有红砖外墙，而将内部结构拆除新建混凝土框架结构体系，新建混凝土构件与既有砖墙进行拉结。

For the part built in the 1970s, the architecture should not only retain the historical traces, but also meet the new architectural functions and appearance. Therefore, the structure adopts the treatment method of "old bottle with new wine", retains the original red brick outer wall, demolishes the internal structure, builds a new concrete frame structure system, and ties the new concrete components with the existing brick wall.

加建部分更新做法示意图（砖墙部分为保留部分）

Schematic diagram of the update method of the addition part (the part of the brick wall is the reserved part )

·屋面部分建筑与结构先后对比几种木屋架形式，从最常见的三角形木桁架和抬梁式木桁架演变为钢木三角形桁架，又根据建筑要求下部钢梁改为悬索，最终形成钢木悬索组合屋架。

Some buildings and structures on the roof have successively compared several forms of wooden roof truss, which evolved from the most common triangular wood truss and beam lifting wood truss to steel wood triangular truss. According to the architectural requirements, the lower steel beam was changed to suspension cable, and finally the steel wood suspension cable composite roof truss was formed.

屋面结构演变图

Evolution diagram of roof structure

该钢木悬索屋架上弦杆采用方形木构件，下弦为钢拉锁，中部设置斜撑。屋脊处设置通长木梁进行整体拉结。两端设置钢柱与下方混凝土构件连接。屋面设置钢檩条搁置望板及瓦片。该屋架结构体系新颖，空间支撑系统简洁有序，充分利用木结构的抗弯和抗压性能和钢拉锁的抗拉性能。屋架上弦木梁尺寸为200mmx300mm。钢拉索采用高钒钢，强度不低于1670MPa。锚具采用牌号40Cr的合金结构钢。连接螺栓采用8.8级C级普通螺栓，连接板采用Q355B钢。

The upper chord of the steel-wood suspension roof truss adopts a square wooden component, the lower chord is a steel zipper, and a diagonal brace is arranged in the middle. A full-length wooden beam is set at the ridge for overall knotting. Steel columns are set at both ends to connect with the lower concrete members.Steel purlins are set on the roof, and watch plates and tiles are placed. The roof truss structure system is novel, and the space support system is simple and orderly, making full use of the bending and compression properties of wood structure and the tensile properties of steel lock. The size of the chord beam on the roof truss is 200mmx300mm . The steel cable adopts high vanadium steel, and the strength is not less than 1670MPa . The anchors are made of alloy structural steel of grade 40Cr . The connecting bolts are made of 8.8 grade C-grade ordinary bolts, and q355b steel is used as connecting plate.

钢木屋架+混凝土框架结构体系采用sap2000建立整体模型和屋架的细部模型分别进行计算分析。通过结构分析可知：

The steel-wood roof truss + concrete frame structure system adopts sap 2000 to establish the overall model and the detailed model of the roof truss for calculation and analysis respectively. Through structural analysis, it can be seen that:

（ 1）由于钢木屋架整体刚度偏弱的，结构整体自振周期较大。前三阶自振周期分别为0.5894s，0.5175s和0.4488s。第一扭转周期与第一平动周期的比值为0.76。

(1) Due to the weak overall stiffness of the steel-wood roof truss, the overall natural vibration period of the structure is relatively large. The first three-order natural vibration periods are 0.5894 s , 0.5175 s and 0.4488 s , respectively . The ratio of the first torsional period to the first translational period is 0.76.

（2）小震作用下，结构的层间位移角（X向1/1693，Y向1/4685）满足规范要求（按混凝土框架控制1/550）。位移比计算中X向为1.30，超过规范要求1.20，小于1.5，Y向为1.08小于规范要求。在设计过程中，对框架柱提高了抗震等级，柱全高进行了箍筋加密，已保证结构抗扭能力，同时钢木屋架在屋脊及端部设置拉梁截面加大，加强屋架的整体性。

(2) Under the action of small earthquakes, the inter story displacement angle of the structure (1/1693 in the X direction and 1/4685 in the Y direction ) meets the requirements of the specification ( 1/550 according to the concrete frame ). In the displacement ratio calculation, the X direction is 1.30 , which exceeds the specification requirement by 1.20 and is less than 1.5 , and the Y direction is 1.08 , which is smaller than the specification requirement. During the design process, the seismic grade of the frame column was improved, and the full height of the column was reinforced with stirrups to ensure the torsional resistance of the structure.At the same time, the steel and wood roof frame is set in the ridge and end of the tensile beam section is increased to strengthen the integrity of the roof frame.

（3）大震作用下，结构最大位移分别为42.0mm（x方向）和11.7mm（Y方向），结构的层间位移角分别为1/268（X方向）和1/610（Y方向）。X方向出现整体出现塑形变形，混凝土构件初步进入塑性，但钢木屋架构件仍保持弹性阶段。

(3) Under the action of a large earthquake, the maximum displacement of the structure is 42.0mm ( x direction) and 11.7mm (Y direction), and the inter story displacement angle of the structure is 1/268 (X direction) and 1/610 (Y direction), respectively. The overall plastic deformation occurs in the X direction, and the concrete members initially enter the plastic stage, but the steel wooden house frame members still maintain the elastic stage.

SAP2000整体模型和屋面细部模型

SAP 2000 overall model and roof detail model

屋架构件应力分析

Stress Analysis of Roof Frame Components

钢木悬索屋架安装过程

Steel and wood suspension roof frame installation process

07  

后记

Epilogue

“当歌曲和传说已经缄默的时候，建筑还在说话。”这是俄国小说家果戈里的名言。习近平总书记2002年为《福州古厝》撰写序言时，便说道：“保护好古建筑、保护好文物就是保存历史，保存城市的文脉，保存历史文化名城无形的优良传统。”

"When songs and legends have been silent, the building is still talking."This is a famous saying of the Russian novelist Gogol. When General Secretary Xi Jinping wrote the preface to "Fuzhou Ancient Houses" in 2002, he said: "To protect ancient buildings and cultural relics is to preserve history, preserve the cultural context of the city, and preserve the intangible fine traditions of the historical and cultural city."

历史保护建筑的修缮与改造对于结构专业而言挑战是极大的。对于这些历经风雨的历史建筑，结构专业需要在满足建筑功能及外观的诉求下，保证并适当提高结构主体的安全性。

The restoration and renovation of historic buildings is a great challenge for the structural specialty. For these historical buildings that have experienced wind and rain, the structural specialty needs to ensure and appropriately improve the safety of the main structure while meeting the demands of building functions and appearance.

在历史建筑的修缮与改造过程中，首先，工程师需要了解原建筑的结构受力体系，理清后期改建的做法，再抽丝剥茧的剥离搭建部分。其次，历史保护建筑中结构修缮和改造也需要“因人而异”，根据具体的结构体系及结构现状，提出不同结构修缮方法。最后，为了满足建筑的功能和外观要求，结构需要根据现场情况，建筑造型，施工水平等多方面考虑，提出切实可行结构处理方法。

In the process of repair and reconstruction of historical buildings, firstly, engineers need to understand the structural stress system of the original building, clarify the methods of later reconstruction, and then peel off the construction part. Secondly, the structural repair and transformation of historically protected buildings also need to be "different from person to person " . According to the specific structural system and structural status, different structural repair methods are proposed. Finally, in order to meet the functional and appearance requirements of the building, the structure needs to put forward practical and feasible structural treatment methods according to the site conditions, architectural modeling, construction level and other aspects.

08  

建成照片

LIVE VIEW