The site was selected as the air-raid shelters used to avoid air raids in Chongqing during the period of the world warⅡ. Through the war years, the air-raid shelters saved tens of thousands of lives while the dwellers in Chongqing spent the tough times with them. And air-raid shelters has definitely already become a spiritual symbol of Chongqing city. But now in the peaceful years, the air-raid shelters are abandoned because of the bad physical environment and lack of the renovation. Then we are looking forward to finding a key element to upgrade this situation. After the experiments and researches, daylight column became the significant way to it. The detailed contents and process are as follows.

During the Anti-Japanese War from 1938 to 1943, Japanese air strikes totaled 203,9166 sorties, and 17,812 bombs were dropped. To avoid air strikes, the citizens dug 282 public air-raid shelters and a capacity of 112,600 people; 1,541 private air-raid shelters and a capacity of 332,400 people. With the construction and development of New City and the prosperity of tourism in Chongqing, the air-raid shelter has become Chongqing’s distinctive city card and a cultural symbol in the hearts of the old Chongqing people.

Although Chongqing’s usual use of air-raid shelters is very rich, such as hotpot restaurants, gas stations and so on, the open space is still only a small part of the whole air shelter.The fundamental reason why the air-raid shelters cannot be used is the lack of light, and the cold and humid environment makes them lose the opportunity to be transformed and used. In order to change the current situation of air-raid shelters, we must solve their lighting problem first.

So in the project, we started our research from four parts. First, we investigated the distribution, current situation and the history of the Chongqing air-raid shelters. Afterwards, we conducted research on the soil cover above the shelter and the space type of the shelter itself. After that, we put forward the idea of using light columns to solve the lighting problems of the air-raid shelter and explored various types of light columns.

Therefore, we tried to combine daylight with air-raid shelters, designed light columns of corresponding forms for air-raid shelters in different spaces, used the light columns to introduce natural light into the air-raid shelters. In order to study the influence of the angle, size and buried depth of the light column on the day lighting of the air-raid shelters, we did a series of experiments by simulating the angle of the sun at different times of the day and record the light intensity of different light column combinations. Then we tried to choose the light column suitable for different functions according to the experimental data.

Finally, according to the experimental results, we proposed various functions for the transformed spaces that were acceptable to the public at various times of the day corresponding to the light., including market, reading, roaming, exhibition, drinking and worship. Each function is associated with different unique daylight environment so we find the most suitable form method to satisfy them. For example, straight light is important for the reading and market while the scattered light could create the holy atmosphere for the people who want to worship there. It is worth mentioning that we also consider the time into the design. We hope it can be the flexible public space according to the different time and weather. Afterwards, in order to put it into use, we designed the detailed structure for them. The air-raid shelters were restored to life and the purpose of enhancing the vitality of the area was achieved. We hope that these light column combinations are examples and references for the future designers or officers who want to reuse these air-raid shelters. In addition, they can be widely used in the various air-raid shelters for the more cities where the air-raid shelters are existed.