readx;? In addition to the main wall, there are many construction facilities on the wall of the Great Wall. Pen, fun, and www.biquge.info

(1) Coupon Gate: Because many soldiers are guarding under the city in peacetime, once there is a war, they have to go to the city to participate in the battle, so there is a round arched gate every short distance on the inside of the Great Wall, called the "Coupon Gate", and there are stone steps leading to the top of the city wall.

(2) Battlements: In the direction of facing the enemy on the outside of the top of the wall, a two-meter-high toothed battlement is built, which is used by combatants to cover themselves when they look at the enemy situation and shoot at the enemy. Specific construction: start to build the buttress from the wall floor to the height of the human chest and abdomen. The buttress is generally built in a rectangular shape. There is a small square hole in the upper part of the battlement, that is, the lookout hole. The left and right side bricks of the lookout hole are in the shape of a figure-eight inside and outside, which is to make it easier to look at the enemy and not be easily shot by enemy arrows. There is a small square hole in the lower part, which is a shooting hole for opening a bow and arrow. The bottom of the perforation slopes downwards to make it easier to shoot enemies under the city.

In ancient times, there were three limits to the range of perforation: arrows shot from the upper limit of the perforation could hit the heart and head above the heart, called the "jackpot", the middle limit could hit the enemy's waist and abdomen, called "amputated waist", and the lower limit could hit the enemy's legs, called "nail feet". If the enemy is close to the city wall, the hole will not work, and the only way to organize the enemy to build a ladder to attack the city is to rely on weapons that throw stones and fireballs and tears. The width of the battlement is about 1.5 meters to 1.6 meters, which can generally cover the body of two people side by side, the height is about 2 meters, and the distance between the battlements is not more than one-third of the width of the battlement. It is worth noting that the battlements on both sides of the central axis of the city gate are symmetrical.

(3) Stone mouth: The height and width of the inner mouth of the stone mouth are about 50 cm, and its masonry method is more complicated. The lower half of its inner mouth is a square hole reserved when building the wall, and the upper half is made of special-shaped bricks to form a coupon shape and turn the face. The outer mouth of the stone cover plate is placed on the edge, and the inner side of the cover plate is chiseled out of the arc-shaped notch, and the outer side protrudes from the wall to become a layer of eaves for the foreign currency of the battlement wall. The outer eaves wall under the outer mouth is built with an arc-shaped groove chute, whether it is a stone wall or a brick wall, the chutes are built with special-shaped bricks. Although the length of the chute is not equal in different sections, ranging from 85 cm to 2 m, the transition is extremely smooth.

(4) Battlement wall: also known as pheasant, located on the outside of the horse road, with a base thickness of 48 cm to 40 cm. The buttress wall is open in the half, and the lower half is built with the stone mouth, which is staggered with the battlement, and there is also a stone mouth for every two battlements. The masonry method of the battlement wall is to use plain ash to build the inner and outer brick walls, and the two skin walls are built along the cross joints, and there is no brick joint. Add a layer of pre-fired capping bricks on the top of the wall and the buttress, and the capping brick is expanded to equal the width of the top of the buttress wall, and the top is made into a slope top, and very few buttresses are used with a buttress mouth.

(5) Yu wall (female wall): On the inner side of the top of the city wall, there is a low wall parallel to the battlement, about one meter high, called Yu wall, also called the daughter wall, it plays the role of a railing. When constructing, it generally starts with a layer of noodle stone with the same width as the wall, and the parapet wall is built on top of the noodle stone. The width of the parapet wall is generally slightly narrower than that of the noodle stone, and the solid wall masonry method is used to build six or eight layers of strip bricks, and the top surface is built with a layer of ridge bricks, and the ridge bricks are specially fired, and some are cut with a mud knife during construction.

(6) Unilateral wall: The so-called unilateral wall is the name of the local people, and the difference between it and ordinary city walls is that it is only a thin wall. The unilateral wall is built in a very treacherous area, the ridge is high and thin, and there is no human passage on the outside of the side wall. There is a famous section of the Simatai Great Wall near Beijing. Unilateral walls are a type of construction that is forced to be adopted only by the situation, and most of them are built with rough rough stone masonry with unprocessed surfaces, and plain ash is used as the bonding material. Because of the variable terrain, the height of the unilateral wall is not uniform, about 2 to 3.5 meters.

(7) Barrier wall: The term barrier wall is a conventional name that has appeared in recent years in the study of the Great Wall, and refers to the wrap wall built along the edge of the large platform on the "ladder" type horse road that collides vertically with the battlement wall. Its shape, height and practice are similar to those of the Yu Wall. It is condescending, facing the trough, and is set up to defend against enemy attacks that have entered the inner side of the side wall. The most obvious is the Mutianyu Great Wall, on the side section of the city wall, the battlement wall has been completely destroyed, but there is a slip of the stone mouth on its inner and outer walls, and it can be seen that there are battlements on both sides.

(8) Horse retaining wall (Juma ditch): A low wall or trench built by the enemy outside the city wall of the Great Wall within the range of cold weapons. The auxiliary fortifications that prevented enemy soldiers from approaching the walls quickly were not designed entirely to defend against enemy cavalry.

(9) The top surface of the city wall: the top surface is generally about five meters wide, which can accommodate five horses to ride together and ten people to ride in parallel. In order to prevent slipping, the pavement is mostly paved with three to four layers of square bricks, and the brick-laying method adopts the form of cross joints, which are built with lime joints and smooth caulking. This also objectively prevents the growth of weeds on the ground. In some sections, due to the steep terrain, the Great Wall city wall can only be built according to the mountain slope, and the top surface of the city wall is also built with stone or blue bricks to form a ladder-shaped ground, which is called a ladder road, otherwise it is difficult for personnel to walk. Some stairways follow the ridge from the base of the mountain to the top of the mountain.

(10) Horse road: next to the city tower, there is generally a sloping passage from the ground to the top of the city wall by the inner eaves wall, which is the passage for people and horses to go down and down the city wall, called the horse road. The width of the road is about 5 to 6 meters, and the inner side of the road is built with a wall of up and down one meter, which acts as a railing. Since the road is generally inclined at about 30 degrees, in order to prevent slipping, the pavement is all made of blue bricks with the side facing upwards and masonry into a cross-shaped caulking. Some of the city walls are higher, and the horse road also repairs the city in the second step shape, and at the entrance of the ground horse road, there is also a gatehouse. Like the north side of the east and west city towers of Jiayuguan, there are spacious horse roads.

(11) Drainage ditch and spit nozzle: In order to drain the stagnant water accumulated on the ground on the top of the city wall in time, a drainage ditch is built at intervals, and the rainwater is discharged outside the city wall foundation through the drainage ditch and the spit nozzle on the inner eaves wall. The spit nozzle generally extends out of the wall about one meter, which well protects the wall foundation from long-term erosion by rainwater.

(12) City Gate Hole: The earliest pass city gate hole is built by the method of "passing through wood"; with the development of construction technology and the extensive use of bricks, the city gate hole is changed to the method of brick and stone cutting (stone swirl) to build, because the city gate hole is a traffic road in peacetime, and it is a pass to attack the enemy in wartime, so it is required to be able to build more spacious. But the method of "passing through the wood" often cannot meet the requirements, and it can only be applied to the door opening with a small span. Using the method of felling (stone rotation), the paint is a semicircle (stone rotation), which can increase the span of the city gate hole to the required size, and the span of many pass ground gate holes is as wide as five to eight meters. Generally, the rectangular stone is used as the foundation, and then the platform is built with three to five layers of rectangular stone, which is about one to one point and five meters high, and then the "upper body" is built with horizontal bricks. After the requirements of the design are met, then cut (stone swirl). When felling (stone rotation), according to the construction requirements, use standing bricks to cut (stone rotation) a layer and then build a layer of bricks, generally to build standing bricks, three to five bricks. There is a rectangular forehead embedded above the doorway. The name of the pass is engraved on it. Some doorways are carved with several layers of carved bricks or stonework on top of the stone whirlpool to increase the solemnity and beauty of the doorway. There are also two wooden gates in the gate, some of which are covered with iron sheets to prevent the besieging enemies from breaking through the gate.

(13) City Tower: The city tower is used to observe the enemy situation outside the border and command operations in wartime. Generally, it adopts the form of one or two storeys and up to three storeys of large roofs. The structure and style of the roof have the palace type, the rest of the mountain type, the hanging mountain type, etc., generally are carved beams and painted buildings, the structure is exquisite, and it stands majestically above the city gate. Their rich and colorful artistic images show dignity, majesty and luxury. On the countertops of the city walls around the towers, brick buttresses were built for use in battle.

(14) Castle platform: On the wall of the Great Wall, a platform about one meter higher than the top of the city wall is built every two or three hundred meters. It protrudes beyond the wall in the direction of the enemy. The outer wall is built with battlements, and in wartime it is condescending, shooting from the flanks to kill the enemy who is attacking the city with ladders. According to the use and construction of the city platform, it is divided into three types: wall platform, enemy platform (enemy tower) and battle platform.

(15) Wall platform: the table top is not much different from the top surface of the city wall, but only a part of the outer eaves wall in the direction of facing the enemy, there are battlements on the wall, and a simple house is built to shelter the wind and rain on the platform.

(16) Enemy Taiwan: Enemy Taiwan is divided into two types: hollow enemy Taiwan and solid enemy Taiwan.

(17) Hollow enemy platform: According to the Ming Dynasty Qi Jiguang's book: "The Actual Record of Military Training" recorded: "Today's construction of a hollow enemy platform, as far as possible through the people and horses to block the place, its commanding height is three or four zhang, the surrounding width is twelve zhang, there are seventeen, eight zhang and one of them, where the rush is dozens of steps or one hundred steps, the slow place or one hundred and fourteen, fifty steps or more than two hundred steps are one, two corresponding, left and right rescue, riding the wall and standing. Building method: the foundation is flat with the side wall, more than four or five feet outside, and more than five feet inside. The middle floor is empty, the arrow windows on all sides, the upper floor is built with a tower, the battlements are ringed, the internal guards are soldiers, the artillery is issued, and the enemy is attacked from the outside, the enemy arrows cannot reach, and the enemy cavalry cannot get close. "The enemy building at Badaling is mostly divided into two floors, the lower floor can live more than ten soldiers, and there are arrow windows around it for observation and shooting. There is a wooden staircase to the top of the building, the roof floor is level, and there are battlements in the walls around it, which can be used to keep an eye on the enemy and shoot the enemy. Some of them are also equipped with fireworks and living equipment.

(18) Solid enemy platform: make a circle, the lower part of the platform is built of solid earth, and the surrounding stone and blue bricks are covered. In Liaodong Town, the second platform in the east of Yuanguan is 13 meters high, the lower part is a solid round dun built of earth, the outer bricks are breaded, the top is paved with bricks to form a plane, and the female wall is built along the circular plane.

(19) Timber structure enemy platform: refers to the appearance of solid enemy platform, the internal structure of enemy platform is mainly made of wood to build a two-story structure, and its exterior is still built of masonry.

(20) Battle platform: In the dangerous place along the Great Wall, there is a building that is taller than the enemy's tower, it is stationed with more soldiers, stored more grain, weapons, and is the stronghold of the pass along the Great Wall. The bottom area is ten meters square, up to about 12 meters, the upper and lower are divided into three layers, the ground floor is a high platform with doors and windows, the second layer has a door hole arrow window perforation and a lookout hole, this is the place where people live and stack weapons and materials, the top floor is open-roofed, and there are battlements built around it.