How to build a building outside the largest city wall

The city gate is the main traffic artery and scenic spot connecting the inside and outside of the city, and it is also the focus of the offensive and defensive war of the ancient city wall. To this end, Zhu Yuanzhang and others took pains to repair, build and transform the Nanjing City Gate several times in the process of building it, in order to strengthen its potential and look forward to its success. There are 13 city gates in Nanjing, each with a considerable watchtower, several wooden city gates and thousands of city gates. According to the shape of the city wall, the position of the gate is asymmetric. The urn built by the gate is divided into two types: inside and outside, and the size and shape of the urn are different. Every city gate has two doors, inside and outside, and the outside is a "thousand-pound gate" descending from the top of the city, which has a solid defensive role; There are two doors made of wood and iron inside. Usually, pedestrians, cars and horses all pass through the hole in the city gate. There are 13 gates around the city wall, Chaoyangmen in the east, Jubao, Tongji and Zhengyang (namely Guanghua Gate) in the south, Sanshan, Shicheng, Liang Qing, Dinghuai and Yifeng Gate in the west, and Taiping Gate, Ce Shen, Jinchuan and Zhongfumen in the north. Zhengyangmen (Guanghuamen) is the thirteen inner doors of Nanjing City Wall and the main entrance of the capital. There are compound urns inside and outside, which is original in the history of China city wall construction. Tongji Gate is the largest of the thirteen inner doors of Nanjing City Wall. It's the urn door in the lucky boat (fish belly). Its internal structure is extremely complex and its shape is unique in China. It has a tower, two residential streets and sidewalks, three urn doors, four doors and some urn holes. The urn is about 690 meters in circumference and 90 meters in facade width, all made of stone. Jubaomen (Zhonghua Gate) is a castle-like gate among the thirteen gates in the inner city of Nanjing City Wall, which is second only to Tongji Gate in scale. This is the south gate of the capital. Zhonghua Gate Castle is the largest existing castle in China, and it is also the most complete and complicated castle and fortress urn in the world. Sanshanmen (Shuiximen) is second only to Jubaomen (now Zhonghua Gate) and slightly similar to Tongji Gate. There are three inner cylinders and four doors, and there is a cylinder between every two walls. The inner tank is boat-shaped or fish-bellied, which is used for garrison defense. Shichengmen (also known as Hanximen) sits east and west, and consists of two urn cities and three gates, all built by arch coupons. Qingliangmen are thirteen gates in the inner city of Nanjing in Ming Dynasty, consisting of a gate and an oval urn. Dinghuaimen, located on the east bank of the outer Qinhuai River, was the gate of the 13th inner city of Nanjing in Ming Dynasty, with unknown specifications. Yifengmen (Zhong Xing Gate) is the main road from the north of the city to Nanjing, and its military position is very important. It is a single-hole city gate with two watchtowers on it. Zhongfumen sits west facing east, almost opposite Yifeng Gate, and it is also the nearest two doors. The two gates take dragons and phoenixes as auspicious symbols. Jinchuanmen sits south to north, named after the ancient Jinchuanmen culvert made Jinchuan River go out of the city. There is Jinchuan Bridge outside the gate, and a sluice is set beside the gate to control the circulation of the moat and the outer Jinchuan River. Compared with other city gates, Ce Shen City Gate is smaller in scale, and it is the only one of the 13 inner city gates of Nanjing Ming City Wall that is left and right open. It is also the only gate with an ancient external urn structure among the thirteen gates, and the urn door is not facing the gate, but opened in the northeast corner of the urn, so it has become the most unique gate among the thirteen gates. The Taiping Gate is the main entrance to the north of Nanjing. Originally a single-hole door, 20 14 was converted into a three-hole door. Chaoyangmen (Zhongshan Gate) was originally a single-hole ticket gate, 1928 (seventeen years of the Republic of China). When the National Government built Zhongshan Avenue to welcome Dr. Sun Yat-sen's coffin, it demolished Chaoyang Gate, dug down the foundation of the gate, rebuilt a three-hole brick gate and renamed it Zhongshan Gate. Wengcheng, called Yuecheng and Qucheng in ancient times, is an accessory building attached to the outside of the city gate in ancient cities. Most of them are semicircles, and a few are rectangles and squares. The outer urn gate faces in different directions, forming a relatively independent facility to guard the gate. Wengcheng is the product of the long-term war practice in China's ancient cold weapon era, a great development of China's ancient city wall construction project, and a mature building facility for guarding the city gate. The urn inside the Nanjing city wall is a departure from the old system of traditional urn building in China. It boldly put the theoretical idea of urn inside the urn into practice and made great development and innovation. Therefore, the shape of the inner urn was first created by the Nanjing city wall in the early Ming Dynasty. Because the inner urn is located inside the city gate, it is possible to set an urn hole (that is, a cave for Tibetan soldiers) to turn the obviously weak part of the city gate defense into a support point in the defense operation, which is impossible for the outer urn. 13 door, Chaoyangmen and Shencemen each have an urn, Shichengmen has two urns, and Jubao, Tongji and Sanshanmen each have three urns. Of the 13 doors, there are four that have been preserved so far: Jubao Gate, Shicheng Gate, Toilet God Gate and Liangqing Gate. Guanghuamen, formerly known as Zhengyangmen, is the main entrance of Beijing, with a compound urn inside and outside, which is original in the history of domestic city wall architecture. Tongji Gate is the largest of the thirteen inner gates in Nanjing, and it is an auspicious boat-shaped (fish-bellied) inner urn gate. With Jubaomen (Zhonghua Gate) and Sanshanmen (Shuiximen) as the highest specifications, there are three inner urn gates. Jubaomen (now known as Zhonghua Gate) is the largest existing city gate, with the largest scale, east-west length 1 18.57 meters and north-south length 128 meters. At the top of the city, there is an original wooden watchtower with iron gates and wooden doors. The iron gate is closed and started with a hinge. There are horse paths on both sides of the urn, and there are 27 hidden soldier caves on the upper and lower floors of the main city and on both sides of the urn. The outer contour city is slightly round, with a circumference of 60 kilometers, mostly made of earth, and has now been turned into a hundred-mile scenic belt outside the Ming Dynasty. Sluices, sluices or culverts are set at the entrance, exit and discharge of rivers under the Nanjing city wall. The entrance and exit of Qinhuai River is divided into east and west sluices. Dongshuiguan still has two gates inside and outside, an iron gate in the middle and three arches, each with 1 1 arch, which effectively decomposes the gravity of the city wall. There are culverts at the entrances and exits of Xuanwu Lake, Qianhu Lake, Biwa Lake and Qinhuai River. The gate is generally made of copper or iron, square, with five holes, the side length is about 125 cm, and the copper or iron culvert pipe is connected inside, with a diameter of about 95 cm. The gate is also equipped with a copper or iron fence. There are two sluices in Nanjing, connecting the inner Qinhuai and the outer Qinhuai. Dongshuimen and Xishuimen are located at the two ends of Shili Qinhuai, and are called the dragon head and the dragon tail. 1953 Xishuiguan was unfortunately demolished, leaving only Dongshuiguan. Dongshuiguan and Xishuiguan are both representatives of superb water conservancy design technology more than 600 years ago. They were two major water conservancy projects in the early Ming Dynasty when Zhu Yuanzhang, the Ming Emperor, made Nanjing his capital, and carried out the construction of the main city and the reconstruction of the water system. Dongshui Guandong Shuiguan is located in the southeast of Nanjing City, on the west side of Tongjimen Bridge in Longpan Middle Road, which is the entrance of Qinhuai River flowing into Nanjing City and the only lock entrance of Nanjing City Wall. Therefore, Dongshuiguan naturally became the leader of Shili Qinhuai. Dongshuitou, formerly known as Shangshuimen, was built in Zhucheng, Yangwu. In 932 (Yang Wu in the fourth year of Taihe), Xu Zhimo, the magistrate of Jinling, ordered the expansion of Jinling City, which became a big city with a high reputation in the world. Dongshuiguan was built in this expansion. During the Six Dynasties, Dongshuiguan was a transportation hub leading to Zhejiang and Suzhou, and merchants from south to north gathered in Dongshuiguan to do business. Today, although Dongshuiguan is no longer prosperous and crowded, it stands within ten miles of the eastern end of Qinhuai River with its majestic momentum. Today's Dongshuiguan site was mainly built in the Ming Dynasty. At the beginning of the Ming Dynasty, Zhu Yuanzhang, the founder of Ming Dynasty, built Nanjing City. In order to control the water level of Qinhuai River, after careful setting, Dongshuiguan was turned into a crescent cave, with three layers of Shuiguan, eleven coupons for each layer, thirty-three coupons for * * *, eleven coupons for the lower layer and twenty-two coupons for the upper and middle layers for Tibetan soldiers to station grain. Now it still exists. In order to consolidate the dynasty and prosper the economy, the Ming Dynasty built a bridge on the main road from Tongji Gate to Nanjing City. Because it is located at the intersection of Qinhuai River at home and abroad, Zhu Yuanzhang named it Jiulong Bridge to lock up the geomantic omen of Ming Dynasty, hoping to contain the geomantic omen of Nanjing with the magical power of dragons, so as to pass on the grand inheritance of Ming Dynasty from generation to generation forever. In the Qing Dynasty, Kangxi Qianlong went down to the south of the Yangtze River and entered Nanjing from Jiulong Bridge. 200 1 When Dongshuiguan was restored, the foundation of Jiulong Bridge was preserved, a large piece of bluestone was repaved from the bridge deck, and 80 stone railings of Lotus Caiyun were set on both sides of the bridge. Four carved stone drums were installed at both ends of the bridge, and nearly 4000 tons of stone were used in the whole bridge, and the bridge foundation did not move at all, which shows the exquisite bridge-building technology of the ancients. Xishuiguan has been demolished for a long time, and Nanjing Xishuiguan is not as famous as its remote counterpart Dongshuiguan. Xishuiguan is located on the south side of Shuiximen, with its back against the city wall. It plays two major functions of water conservancy and national defense, and its functional design is very accurate. Relying on this underground drainage system of the ancients, heavy rain is not easy to cause road water accumulation. After the Ming Dynasty moved its capital to Beijing, it was rebuilt by imitating the dredging system of Nanjing underground water system. Therefore, every time it rains heavily in Beijing, the Forbidden City generally does not accumulate water, because it has a good underground drainage system, which is also an important role played by water conservancy projects such as Xishuiguan and Dongshuiguan at that time. According to the textual research of the Origin of the Geographical Names of Guli Qinhuai, Xishuiguan was called Xiashuimen in the Southern Tang Dynasty in the Five Dynasties, and was changed to Xishuiguan in the Ming Dynasty when the city was built, and Yanyue Cave was set up. In Qing Dynasty, there was a Yintai Cave between Xiafuqiao and Yanyue Cave, also known as Yuntai Cave. 1935, Xishuiguan sluice was built in the former site of Yuntai Cave. After the founding of the people's Republic of China, it is still a small flood control and drainage facility. It can be seen that Xishuiguan played an important role in protecting Nanjing from floods in history. In addition to flood control and drainage, Xishuiguan has also made great achievements in military, political and economic fields. It is said that there were some "small organs" in the construction of Xishuiguan at that time: Xishuiguan had two city gates, a bridge and a cave for hiding soldiers. One gate is inside the city wall, and the other gate is at the outlet of the Qinhuai River. There is a porous arch ticket tunnel under the city wall, which is sealed with stones to prevent the enemy's "water ghost" from sneaking into the city. The city wall is piled between two city gates. The architectural layout of Dongshuiguan and Xishuiguan is basically the same, echoing each other. Since the Six Dynasties, the waterway sandwiched in the middle has been a place where famous families live together, merchants and scholars gather, Confucianism flourishes, and finally the prestigious "Ten Li Qinhuai" is formed. Although the architectural structure of Dongshuiguan and Xishuiguan is the same, after the Six Dynasties, the prosperity of Xishuiguan was far beyond the reach of Dongshuiguan at that time, which was contrary to the current situation. Xishuiguan is the mouth of the Inner Qinhuai River, which is connected with the Yangtze River and has a wharf. It can be regarded as the throat of Nanjing's "import and export" and the busiest material distribution center in Nanjing at that time. In addition to goods, if foreigners want to enter Nanjing by water, they must disembark from Xishuiguan and then enter the urban area through Shuiximen. There are also checkpoints on the dock, and those who want to disembark must show their certificates before entering the city. This is probably related to the "spy case" that happened during the Hongwu period, because the business was developed at that time, and many foreigners would come to China. After the unpleasant things happened during this period, the import and export management became stricter. The prosperity of Xishuiguan can also be proved by archaeological discoveries. In the late 1980s, a number of cultural relics from the Six Dynasties, Sui and Tang Dynasties, Song Dynasty and Ming and Qing Dynasties were unearthed in Xishuiguan. The moat around Nanjing Ming City Wall (only the outside of the wall east of Taiping Gate has not been built) is an important part of Nanjing Ming City Wall. The water source of the moat comes from Qinhuai River, Qingxi River, Jinchuan River, Xuanwu Lake, Qianhu Lake and Biwa Lake. It is formed by dredging and excavating the river outside the city wall and introducing the river into the city. The wide water surface of the moat sets off the tall and solid Nanjing wall, which makes the invading enemy daunting. The existing moat of the city wall is 3 1. 159 km long, and the distance between the city wall and the moat is 334 meters at the widest point and 9 meters at the narrowest point. In fact, the "hidden soldier cave" is a brick coupon door with a closed inner end, which can be used for soldiers to rest and store military supplies in wartime. The southernmost wall of Jubaomen (Zhonghua Gate) has two floors *** 13, and there are seven floors under the left and right walls, totaling 27 floors. Each cave can accommodate 100 soldiers, and * * * can hide more than 3,000 soldiers. This facility was extremely rare in other big cities in ancient China.