The spatial distribution of moderate and strong earthquakes and felt earthquakes in Jianghan Basin has certain regularity. Historically, moderate and strong earthquakes were mainly distributed in two dense zones.
One is the northeast, from Changde via Anxiang, Shishou, Tianmen, Xiantao to Anlu. The frequency and intensity of earthquakes in this dense area are relatively large; Another concentrated epicentre is NW-trending, from Gongan to Yichang, with nearly 50 felt earthquakes and 1 strong earthquakes recorded in history.
At present, seismic activities, especially strong earthquakes, are mainly distributed around the basin, and there are only sporadic earthquakes in the basin, which is generally calm. At the same time, Jingzhou city is located in Jianghan seismic belt in the middle and lower reaches of the Yangtze River, and the intensity of seismic activity in this seismic belt is not high compared with other seismic belts.
From the seismological point of view, the hydrogeology of Jingzhou is in a normal state at present, and the possibility of a destructive earthquake in Jingzhou is relatively small from the perspective of the earthquake trend in the whole province. Earthquake is a natural phenomenon. Take Hubei as an example, there are many small earthquakes 100 every year, with the magnitude of 1-3, which can hardly be felt on the ground.
Jingzhou city is located in Jianghan earthquake zone, and there are about two or three earthquakes every year on average. In the earthquake zone, the frequency is actually very low.
There has never been an earthquake in Wu Hanyou in history. There have been three earthquakes of magnitude 6 or above in our province. Hubei province is located at the junction of two fault block tectonic units in East China and South China. The geological structure, fault activity and neotectonic movement are complex, which has the geological background of earthquakes of magnitude 6 or above. There are 33 destructive earthquakes (above 4.7) recorded in history, including 3 earthquakes above 6.
In March 788, an earthquake of magnitude 6.5 occurred in Zhushan. 1856, an earthquake of magnitude 6 or above occurred in Daluba, Xianfeng, causing landslides for more than ten miles, which accumulated into a dam, forming the largest preserved earthquake-stricken lake in China-Xiaonanhai.
1932, an earthquake of magnitude 6 occurred in Huangtugang, Macheng, killing many people and animals. The recorded earthquakes in Wuhan history were 1.470+0.65438, and earthquakes of magnitude 5 occurred in Wuchang and Hanyang. 1in March and April of 605, an earthquake of magnitude 4, 3/4 occurred in Wuchang (Jiangxia) and other places; 1June, 605, an earthquake of magnitude 5 occurred in Wuchang and Hanyang. 1June, 897, an earthquake of magnitude 5 occurred in Wuchang and Hankou. 1March, 930, an earthquake of magnitude 4 occurred in Wuhan. During the period of 1932, people were injured and houses collapsed in Wuhan due to the earthquake of magnitude 6 in Huangtugang, Macheng.
After liberation, there was no record of major destructive earthquakes in Wuhan.
3. Has there ever been an earthquake in Huanggang City, Hubei Province? The biggest earthquake in China's history killed 830,000 people. In the thirty-fourth year of Jiajing in Ming Dynasty (1555 65438+123 October), strong earthquakes occurred in Weinan, Shaanxi and Zhou Pu, Shanxi, killing more than 830,000 people.
This earthquake is the largest one with clear written records in the history of China. Amin writer Zhu Guozhen wrote in "Architectural Essays": When the earthquake occurred, earthquakes occurred in Shaanxi, Shaanxi and Henan at the same time.
Weinan, Zhou Pu and other earthquakes: "(Earthquake) sounds like thunder, and chickens and dogs bark." Affected by the earthquake, the Yellow River and the Weihe River were cut off, the river rose and flooded, and Huashan and Zhong Nanshan were singing.
After the earthquake, the gate of Weinan fell to the ground, all the walls of Huazhou collapsed, and all the walls of Tongguan and Puban collapsed. As for the houses and official residences, they are all in ruins.
More than 830 thousand people died in this earthquake, and there are countless unknown and unreported dead. Generally speaking, the death toll in Tongguan and Puban is about seven tenths of the local population, six tenths in Tongzhou and Huazhou, five tenths in Weinan, four tenths in Lintong and three tenths in Shaanxi Province.
Other counties have different deaths due to different locations. Many families were killed in the earthquake.
For example, 85 households in Mi Zhongliang's family were killed at the same time, and 9 households in Chen's family1/kloc-0 were killed at the same time. There are many other families whose death toll has reached 100.
Among the dead were some court officials, including Shang Shu, Ma Li, Nan Guang Lu Qing and Wang Weizhen who toasted the south, and others, including doctors Xue Zuxue, He Chengguang, scholars Wang Shangli and imperial adviser Yang Jiuze. During the earthquake, Han fell into the kang stove and was burned to ashes.
Xue Zuxue fell into a water hole more than ten feet deep during the earthquake and drowned. Horsepower was buried deep in the earth hole.
On the night of the earthquake, Wang Weizhen was chatting in her mother's room. When playing drums for the second time, mother asked Wang Weizhen to go back to her room to rest.
Wang Weizhen went back to her house, but before she went to bed, the earthquake happened. Wang Weizhen rushed out to call her mother, who had fallen asleep.
Later, Wang Weizhen was crushed to death by the collapsed wall. Although Wang Weizhen's mother's house also collapsed, she survived. After the earthquake, some villagers in Weinan and Tongzhou took advantage of the chaos to rob the official warehouse, which was suppressed and the incident was calmed down.
4. Was there a destructive earthquake in Hubei? Hubei is a moderately strong earthquake area, with 33 destructive earthquakes in history. Among them, there were three earthquakes of magnitude 6 or above, namely Zhushan earthquake of magnitude 6.5 in March, 788, Xianfeng earthquake of magnitude 6.25 in June, 1856 and Macheng earthquake of magnitude 6 in June, 932.
According to relevant geological data, there is also a fault zone in Tuanfeng, Macheng, Xianning and Chongyang. This fault has experienced two earthquakes with magnitude above 5 in the past 500 years, but it is currently in a relatively stable state. Wuhan is in a relatively stable region with few destructive earthquakes. The strongest earthquakes occurred in Jiangxia 1470 and 1605. Usually, there are few microseisms below magnitude 3.
5. Is it possible for Jingzhou and Wu Hanyou to have earthquakes of magnitude 5 or above? According to the provincial seismological bureau, Wuhan is very safe, and the possibility of a destructive earthquake of magnitude 5 or above is very small, less than one in ten thousand. Hubei is a moderately strong earthquake area, with 33 destructive earthquakes in history. Among them, there were three earthquakes of magnitude 6 or above, namely Zhushan earthquake of magnitude 6.5 in March, 788, Xianfeng earthquake of magnitude 6.25 in June, 1856 and Macheng earthquake of magnitude 6 in June, 932. According to the relevant geological data of our province, there is also a fault zone in Tuanfeng, Macheng, Xianning and Chongyang. This fault has experienced two earthquakes with magnitude above 5 in the past 500 years, but it is currently in a relatively stable state. Wuhan is in a relatively stable region with few destructive earthquakes. The strongest earthquakes occurred in Jiangxia 1470 and 1605. Usually, there are few microseisms below magnitude 3.
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6. History of Jingzhou Yangtze River Bridge Jingzhou Yangtze River Bridge was built in Jingjiang reach of the middle reaches of the Yangtze River, connected with National Highway 3 18, Yihuang Expressway, Xiang Jing Expressway and Jingchang Expressway, and it is a throat project for 207 national highway to cross the Yangtze River. The bridge consists of nine parts: North Shore Approach Bridge, Jingzhou Dike Bridge, North Shore Beach Bridge, North Branch Navigation Bridge, Sanbazhou Bridge, South Branch Navigation Bridge, South Shore Beach Bridge, Jingnan Trunk Bridge and South Bank Approach Bridge, with a total length of 4,397.6 meters, a deck width of 24.5 meters, two-way four lanes and a daily traffic capacity of more than 20,000 vehicles.
Jingzhou Yangtze River Highway Bridge, located in Jingzhou City, Hubei Province, is a super-large bridge across the Yangtze River in 207 national highway. The river at the bridge site is about 3000 m wide, and there is a sandbar in the river called Sanbazhou. Sanbazhou divides the bridge site into two branches, the north branch is about 700 m wide, the south branch is about 450 m wide, and Sanbazhou is about 1 100m long. The total length of the bridge is 4 177. The exposed stratum on the surface of the bridge site area is Quaternary soft accumulation sandy pebble layer, and the underlying bedrock is mudstone and siltstone. The buried depth at the top of the bedrock is 1 16 ~ 128 m, the design driving speed is 100 km/h, and the design load is: steam 2 exceeds 20, and suspension is 2/kloc. Bridge deck width: the clear width of the carriageway is 2 1.5m, and the total width of the bridge deck is 24.5m (27.0m for the cable-stayed bridge), with no non-motor vehicle lanes and sidewalks. The bridge is composed of nine parts, from north to south: North Shore Bridge: 926 meters long.
North Bank Approach Bridge (1) 22 m *20 m prestressed concrete simply supported hollow slab.
(2) 93+ 150+ 93 (m) prestressed concrete continuous beam spans Jingjiang levee bridge.
(3) The 5 m *30 m prestressed concrete simply supported T-beam of the North Shore Beach Bridge. Main bridge: 2557 meters long.
(4) 200+ 500+ 200 (m) prestressed concrete cable-stayed bridge with navigation hole at the north branch.
(5) Sanbazhou Bridge100+6 *150+100 (m) prestressed concrete continuous beam.
(6) Nancha Navigation Hole Bridge 160+ 300+ 97 (m) prestressed concrete cable-stayed bridge. Nan 'an Bridge: 270 meters long.
(7) 8 m *30 m prestressed concrete simply supported T-beam of Nan 'antan Bridge.
(8) 50+ 80+ 50 (m) prestressed concrete continuous beam spans Jingnan main dike bridge.
(9) The 9 m *30 m prestressed concrete simply supported T-beam of the south bank approach bridge.
The geological structure of Jingzhou Yangtze River Highway Bridge is complex, and the cable-stayed bridge with a main span of 500 m PC has a long span, ranking first in China and second in the world. The height difference between the two towers of PC cable-stayed bridge with Nancha sister tower is 35.4 m, which is rare in China. Sanbazhou continuous beam bridge 1 100 m is the longest continuous beam bridge in China at present. The main technical features of design and construction are as follows:
(1) Conduct pile test at Pier 28 before pile test. Pile diameter 1.5m, depth 80m, horizontal maximum load 120t and vertical maximum load 3400 t, which is the largest in China at present. Verify the accuracy of geological data through pile test and optimize the design.
(2) Foundation construction The underwater foundation of the main tower and continuous beam pier of Sanbazhou cable-stayed bridge adopts the construction scheme of steel pipe pile supporting platform and double-walled bottomless steel box. The steel box has an inner diameter of 33 m, an outer diameter of 36 m and a height of 35m, and the back cover concrete is poured for 4250m at a time. In the pile foundation construction, the domestic large-scale drilling rig and self-made drill bit were used to successfully solve the mechanical equipment and construction technology of deep-water large-diameter bored pile crossing 80 m sandy pebble layer.
(3) Design of main girder The main girder of cable-stayed bridge adopts prestressed concrete ribbed slab structure, which has clear stress, light structure and convenient construction.
(4) Main girder construction The main girder is constructed with the developed front fulcrum hanging basket, with a section length of 8m and the heaviest section exceeding 530t.
(5) Static model test In order to check the correctness of the design calculation and ensure the overall strength and stability of the cable-stayed bridge, the static stability test of the 1∶30 aluminum alloy model of the cable-stayed bridge with a main span of 500 m in the north branch was carried out, so as to fully grasp the distribution and change of cable force and internal force of the main girder under the action of self-weight, vehicle load and unbalanced construction load, determine the load conditions of the structure when the maximum cantilever state and the completed bridge state are unstable, and carry out the structural stability test at the same time.
(6) Wind tunnel test: segmental model wind tunnel test, buffeting response analysis and bare tower aeroelastic model test are carried out for cable-stayed bridges with main spans of 300m and 500m, and full-bridge model wind tunnel test is carried out for PC cable-stayed bridges with main spans of 500 m ... By setting reasonable temporary piers, the wind stability problem with the maximum double cantilever length of 248.6 m is solved.
(7) Simulation analysis Through simulation analysis, the structural deformation coordination and cable fatigue of the 300m main span high-low tower cable-stayed bridge are verified.
(8) Construction Monitoring During the construction of the main tower, main girder and continuous beam bridge of Sanbazhou Cable-stayed Bridge, strict monitoring measures were formulated to grasp and analyze the line shape of main girder, the stress and strain of steel bar and concrete, and the tension change of stay cables in time to ensure the safety of the construction process.
(9) Seismic response analysis The seismic response analysis of the bridge includes structural dynamic analysis and structural seismic response analysis, as well as the evaluation of sand liquefaction in the soil layer at the main pier.
(10) Climbing formwork construction The main towers of two cable-stayed bridges adopt the climbing formwork construction technology of large integral steel formwork (10m high), which ensures the quality and appearance of concrete.
7./ What year was the biggest earthquake in the history of Changde City? Changde earthquake 163 1?
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According to historical records, the earthquake caused serious casualties and property losses. According to the analysis of the ancient earthquake relics recently discovered in Changsha, there have been at least two earthquakes of magnitude 7 or above in Hunan. There are three moderate earthquakes recorded in Changsha in history. Changsha is one of the key cities for monitoring and defending the national 13 earthquake determined by the State Council.
Chinese name
Changde earthquake
time
163 1 year
birthplace
Changde
important
Level 6.8
Epicenter intensity
Not less than nine degrees
Dissemination area
Hunan, Hubei, Jiangxi, Anhui and other four provinces
Earthquake history
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Historically, earthquakes have occurred in various cities and States in Hunan. Since 1500, destructive earthquakes have occurred in 10 cities in the whole province, accounting for more than 20 times. The Changde M6.8 earthquake 163 1 is one of the largest earthquakes recorded in the inland of South China so far.
history
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According to the historical data "edited by Mayor Lu Chong of Shi Ming", it is recorded that: "The midnight earthquake of Changde House in Huguang was audible, and it came from the northwest, and the sound was like thunder, which covered the sky for a while. What is shocking is that Jing Quan (Sakamoto) flooded, the ground cracked, mud gushed out, six yellow sands, countless Fu Rong palaces and walled houses collapsed, and 60 men and women were killed. " "On the same day, Taoyuan, Longyang, Yuanjiang, Wuchang and Chenzhou belong to Yuanling and Yuanzhou, Jingzhou belongs to the Association, Changsha belongs to Changsha, Hua Shan, Xiangtan, Ningxiang, Xiangyin, Liquan (Ling) and Anhua, and Chengtian belongs to Zhongxiang, mian yang, Qianjiang and Jingling counties. The next day, Lizhou was also shaken several times, the inner city cracked, the walled houses collapsed, and more than ten households died. Wangjiajing spewed yellow water, iron ruler weir spewed black water, Pengshan collapsed and the river was silted up. Jingzhou Prefecture was also shocked on the same day, with four out of ten broken walls, three out of ten houses and more than ten soldiers and civilians. "
These records of the long side of Chongzhen are all recorded from Bai Shilin's report. According to the records of the Ming Dynasty, Bai Shilin's title was Patrol Press. The governor was an official system in the Ming Dynasty, and his duty was to patrol on behalf of the emperor, and he cared almost nothing wherever he went. Thirteen provinces, one for each province. Bai is an official and often visits Huguang (namely Hunan and Hubei) provinces. Bai's report was obviously based on the report of local officials at that time. According to other historical data, it may be within 3 months after the earthquake. Therefore, the records in Chongzhen Changbian are basically true in terms of the time, area and damage degree of the earthquake, and its information is the most primitive, detailed and reliable.
Changde earthquake is also recorded in some local chronicles. For example, the Records of Changde Mansion compiled in the 9th year of Kangxi (A.D. 1670) recorded: "In the 4th year of Chongzhen, at the turn of the Weixin Haizi on July 17th, the earthquake in Fucheng was abnormal, the houses in the city collapsed, and the city walls collapsed, causing countless casualties, men, women and children. The soil is cracked everywhere, and the black spring is twenty or thirty feet high. There are three or four earthquakes every day, and they roar like thunder. People were frightened. For more than a month, the street sleepers suddenly fell into the field and the water was exhausted. " (Volume II, page 7 1). In the 22nd year of Kangxi (A.D. 1683), Anxiang County Records recorded: "In the third year of Chongzhen, there was an earthquake on the evening of July 17th in Xinwei (Xinwei should have been Chongzhen for four years, the original text was incorrect), and the ground cracked and water surged from the northeast with thunder. There, the ground collapsed, red water overflowed, trees fell to the ground, birds and animals panicked and screamed, killing and injuring countless people, and the people built buildings to prevent disasters. There was another big movement on 10/5, and the rest of the small earthquakes were different. " (Volume 2, page 24). In the 24th year of Kangxi (1685), the Records of Yuezhou Prefecture recorded: "In four years of Chongzhen, there was no major earthquake, and Changli was very serious. When the earthquake happened, there seemed to be golden eyes flashing around the house, which made people feel embarrassed. People sleep in the moonlight and dare not enter the house. The location is cracked, the black sand is surging, the smell is threatening, and the land is exhausted "(Volume II, 14 page). In addition, 33 counties in Hunan have historical records of earthquakes.