Today is the first day to go to the construction site. Because the construction site is in prison, the management is strict, and there are some formalities to go through in and out, so I haven't been able to enter the construction site yet. I have to wait a few days before I can enter the construction site. In recent days, I will learn to do some indoor work first. Today, I mainly learned the basic situation of some construction sites. This project is the expansion project of Fuqing Prison 1 #, 3 #, 4 # and 5 # dormitories (partial reconstruction). The construction unit is Fuqing Prison, the design unit is Fujian Wu Min Architectural Design Institute Co., Ltd., the exploration unit is Fujian Forestry Exploration and Design Institute, the supervision unit is Fujian Engineering Consulting and Supervision Co., Ltd., and the construction unit is Fuqing Xiuhui Construction Engineering Company. It covers an area of about 500 square meters, with an investment of about 3 million yuan and a construction period of 270 calendar days. This is a relatively small project.
July 1 1 Tuesday morning: sunny afternoon: sunny average temperature: 27℃ ~ 37℃
Because the entry and exit procedures have not been cleared, I can't enter the construction site. In the morning, the builder arranged to do some simple indoor work. The first task of my internship is to draw the column network plan of the expansion of 3 # prison house with CAD. The drawings looked simple, so I agreed. However, because there is no CAD course in the school, some basic CAD knowledge is self-taught, and there are few opportunities to draw with CAD at ordinary times, so the painting is slow, but it was finally finished before noon. After inspection, the constructor found many mistakes, and some symbols were drawn in the same way without understanding their meanings, but they were all wrong. For example, the column symbol is 2 1(2 1A). In the design description, there are columns representing floors 3 ~ 6 in brackets, and columns representing floors 1~2 outside brackets. When I draw, each layer is represented by 2 1(2 1A). After an afternoon of revision and redrawing, we finally drew a drawing that meets the requirements of the builder.
Wednesday morning of July 14: Heavy rain afternoon: Average temperature of heavy rain: 25℃ ~ 30℃
Today, the builder brought back some test data of test blocks and taught me how to evaluate whether the test blocks are qualified or not. The first is to learn the examination and evaluation methods of coagulation intensity. There are two main methods: ① statistical method ② non-statistical method.
① Statistical methods mainly meet the following conditions: (10 group or more)
Mfcu≥fcu，k+0.7σo fcu，min≥fcu，k-0.7σo
And when the strength is less than or equal to ≤C20, FCU, min is more than or equal to 0.85 FCU, k.
When the strength >; At C20, fcu, minimum value ≥0.90fcu, k
Among them:
Mfcu: average compressive strength of concrete cubes in the same acceptance batch (N/mm2)
Fcuk: Standard value of compressive strength of concrete cube (N/mm2)
σo: standard deviation of compressive strength of acceptance cube.
Fcu, min: the minimum compressive strength of the same batch of concrete cubes.
σo = 0.59/m∑δFCU，I
Among them:
Fcu, I: the difference between the maximum and minimum compressive strength of the cube of the first batch of specimens.
M: the total number of data batches used to determine the standard deviation of compressive strength of concrete cubes in the acceptance batches.
When there is not enough data to find the standard deviation, the following formula should be satisfied:
Mfcu- into 1 S，fcu≥0.9fcu，k
Fcu？ Minimum value ≥ 2fcu, k
SFCu-standard deviation of compressive strength of concrete cube in the same acceptance batch (N/mm2)
When sfcu
Enter 1, and enter 2: qualification judgment coefficient.
The number of specimens is10-1415-24 ≥ 25.
Enter11.701.651.60.
Enter 2 0.9 0.85 0.85.
Sfcu=[(∑ fcu？ i2-n？ mfcu2)/(n- 1)] 1/2
② Non-statistical methods (below 10 group)
Mfcu≥ 1. 15fcu？ k
Fcu？ min≥0.95fcu？ k
The evaluation method of mortar strength is similar (mathematical statistics).
Mfm.k (average value) ≥fm.k (design strength grade)
Frequency modulation kmin (minimum value) ≥0.75 frequency modulation k
After learning these theoretical knowledge, I evaluated many test reports myself and found that they all met the requirements. July 6th morning 15: heavy rain afternoon: average temperature of rainstorm: 24℃ ~ 28℃
The main task today is to sort out the data recorded by building settlement observation, draw the plane partition map of settlement observation points, and draw the settlement observation curve of each point. The layout of settlement observation points is composed of the main outline of the building, settlement observation points and instrument drawings. There are 8 observation points in the figure.
The settlement observation curve of each point shows the cumulative settlement of the first observation on the coordinates, and the settlement is calculated according to the elevation measured at regular intervals.
Sunday morning in July 16: rainstorm afternoon: average temperature of rainstorm: 25℃ ~ 29℃
Today, I mainly learn how to sort out the "Inspection Lot, Sub-item, Division (Sub-division) Engineering Quality Acceptance Records" in the "Construction Engineering Quality Control Data". These data can be divided into four sub-items: ① foundation and foundation; ② Main structure; ③ Building decoration; ④ Building roof; And each subdivisional work is divided into several subdivisional work and subdivisional work inspection lot.
These data are the acceptance records of each process in the process of engineering construction.
(division) (division)
Foundation and foundation: unsupported earthwork, supported earthwork, foundation treatment, underground waterproofing of pile foundation, concrete foundation, reinforced concrete masonry foundation and steel structure.
Main structure: concrete structure, steel reinforced concrete structure, masonry structure, steel structure, wood structure, grid structure and cable-membrane structure.
Decoration: floor, plastering, doors and windows, suspended ceiling, light partition wall, decorative board (brick), curtain wall, painting, pasting, soft package and details.
Roofing: coiled material waterproof roof, coated waterproof roof, rigid waterproof roof, tile roof and thermal insulation roof.
Of course, not every project has all sub-division projects, but there are several. July/morning of KLOC-0/day/morning of KLOC-0/7: Afternoon of moderate rain: cloudy; average temperature: 25℃ ~ 30℃
Today, it is mainly to sort out the safety and function testing data of construction projects. This data can also be divided into six parts: ① buildings and structures; ② Water supply and drainage and heating; ③ Building electricity; ④ Intelligent building; ⑤ Ventilation and air conditioning; ⑤ Elevator. Today is mainly to sort out the information of buildings and structures. These materials are all test records, measurement records and the like. Such as: ① test records of roof rainwater (water storage); (2) groundwater waterproof effect inspection records; (3) groundwater storage test records with waterproof requirements; (4) building verticality, elevation, total height measurement records; ⑤ Inspection records of flue and extraction pipeline; ⑧ Physical performance test records of curtain wall and external window; Today building settlement observation records; Pet-name ruby energy saving and heat preservation measurement records; Pet-name ruby indoor environment inspection report.
Tuesday, July 18, morning: afternoon: average eye temperature: 26℃ ~ 35℃
Today we mainly study the drawings of the construction site. These drawings can generally be divided into four parts: ① building ② structure ③ water supply and drainage ④ electricity. Each part of the drawings consists of a catalogue, general design instructions, various drawings and modification notices. Design overview is a necessary description of drawing design. For example:
An overview of architectural design includes: design basis, general situation of the project, and various sub-projects (wall, floor, ceiling, roof, outdoor works, doors and windows, painting, etc.). ).
Architectural drawings are mainly composed of plan, elevation and section.
The structural diagram is mainly composed of foundation, column network, structure of each floor, roof plan, beam and slab reinforcement diagram, roof reinforcement diagram, stairs and other details. There are few electrical and water supply and drainage construction drawings, so there are many places that I don't understand, so I rarely read them. Wednesday, July 19: AM: PM: Average eye temperature: 27℃ ~ 36℃
There are four extension buildings in this project, one of which has been capped, and the acceptance of building electrical concealed works will be carried out tomorrow. The concealed work of electrical installation engineering refers to the construction process of electrical specialty that will be concealed by the next construction process of this specialty or other professional construction processes, and the main inspection contents of electrical concealed work of engineering projects that can no longer be inspected under normal circumstances are: ① variety, specification and quantity; ② Location, elevation and coordinates; ③ Quality standard requirements; ④ Quality status of installation process.
The construction unit shall, in accordance with the provisions of the current national standards, do a good job in the inspection and acceptance of concealed works of electrical installation projects, and fill in the acceptance records of concealed works. If necessary, drawings shall be attached, and professional supervisors (professionals of the construction unit) shall check whether it meets the requirements and make clear the opinions that can be concealed. You can't hide until the visa is confirmed. Take cover engineering acceptance records should be clear, specific and complete, the conclusion should be accurate, and the visas of relevant personnel should be complete.
Friday, July 265438 +0: AM: PM: Average eye temperature: 27℃ ~ 36℃
Because the procedures for entering the construction site were unclear, I was introduced to another construction site by my classmates in order to know more about the construction site. The site is the high-tech experimental center building of the Provincial Academy of Agricultural Sciences, which is in the foundation construction stage. Today is the first time I came to the construction site, and I saw the foundation pit and supporting structure. I have seen it before when I passed by the construction site, but most people know what it is. I used to see the formwork of brick foundation beam and pile cap, but I thought it was a pool or something. Seeing the steel pipe on the supporting structure, I thought it was a municipal pipeline. Now I finally know the names of those things. The supporting structure is used to support the surrounding earthwork and consists of I-beams and steel pipes. I-beams stand around, and steel pipes are used for support. Piles are all cast-in-place piles with a diameter of one meter. The size of the cap varies with the number of piles, and the height is about one meter. Some large pile caps are more than two meters.
Saturday morning, July 22nd: Eye afternoon: Average eye temperature: 28℃ ~ 38℃
I spent most of my time on the construction site today. The workers on the construction site mainly dig the pit of the pile cap and cut the pile. Due to the large volume of the pile cap and the large amount of earthwork, it will take several days to dig the pile cap, and pile cutting is also a time-consuming work. It takes a long time to cut a pile. Pile cutting does not mean to cut off all the pile heads, but depends on the design requirements, generally at the bottom of the pile cap100 mm. Moreover, the reinforcement in the pile must extend into the pile cap 1M to play an anchoring role. Because the construction site has not started on a large scale, there are relatively few workers. Almost all these works will be carried out on the construction site in the next few days. Part of the pile caps have been dug and bricklaying has begun. Bricklaying is for modeling. Because the template is underground, it can't be built with templates as usual. At the same time, the height of the cap is relatively high and the earth pressure is relatively high. Masonry with a thickness of 24mm is adopted, and the height of foundation beam is relatively small, only 12mm thick, and masonry with a thickness of one shun and one ding is also adopted. Sunday morning, July 23rd: Eye afternoon: Average eye temperature: 28℃ ~ 38℃
The construction site is still cutting piles, digging caps and laying bricks, which is no different from the previous days. So today I mainly study the construction drawing and get some basic information about the project, as follows:
This project is the building of Fujian Agricultural High-tech Experimental Center, designed by China Northeast Architectural Design and Research Institute and constructed by China Construction No.7 Bureau and No.3 Company. (1) this project consists of basement, ground 18-22 main building and four-story podium; ② The cast-in-place reinforced concrete frame-shear wall structure is adopted. The safety level of building structure is Grade II, the safety level of pile foundation is Grade I, the design level of foundation is Grade A, and the seismic fortification intensity is 7 degrees. Seismic grade of institutions: a, the seismic registration of basement frame is Grade II, and the seismic grade of shear wall is Grade II; B, the seismic grade of the above-ground part and the main building frame is Grade II, and the seismic grade of the shear wall is Grade II. (3) the underground basement is the local six-level civil air defense basement; ④ The foundation is brick hole bored pile, and the bearing layer at the pile end is moderately weathered granite.
Monday morning, July 24th: sunny afternoon: cloudy; Average temperature: 27℃ ~ 35℃
Today is mainly to participate in the puddle pay-off. In order to facilitate the pay-off, after the completion of the supporting structure, the construction personnel mark the axes on the horizontal supporting steel pipe of the supporting structure, so as to directly measure according to the axes marked on the steel pipe during the later pay-off.
Setting-out is to put the drawings on the construction site and measure them directly according to the distance from each point to the axis, but some adjustments may be made according to the specific situation of the construction site, and the set-out line may not be exactly the same as the drawings. This puddle is different from the drawing. In design, the size of one of the puddles is1500×1500×1300, but it is actually used as a cushion, waterproof layer, etc. The size has to be expanded, and the shape of the puddle excavation is not a cuboid on the picture. In fact, the upper sole is different, and the upper sole is bigger than the lower sole. Templates and basements will be built later. Finally, the cuboid on the drawing is formed, which is to prevent stress concentration.
Sunday morning of July 25th: rainstorm afternoon: average temperature of rainstorm: 26℃ ~ 3 1℃
It's raining heavily today, so the construction site can't be implemented, so today I mainly study drawings and some specifications in the office. Because I can't see how the initial line of the construction site is put, I understand the initial positioning of the building.
The building consists of several axes, one of which is the main axis. As long as the position of the main shaft is determined, other shafts can be determined according to the main shaft.
The layout method of the main axis should be determined according to the design requirements and site conditions. Generally speaking, there are four methods:
(1) The principal axis is laid out according to the property line, and the boundary that defines the location of the building boundary is called the property line, which is generally parallel to the road centerline.
(2) Layout the main axis according to the road centerline.
(3) According to the main axis of the original building, this method is often used for the new construction or expansion of existing buildings.
(4) Layout the main axis of the building according to the control points.
Control points have been laid on the construction site, and the coordinates of the axis points of the proposed building are known, so the main axis of the building can be laid out according to the control points.
Sunday morning, July 26th: Heavy rain afternoon: Average temperature of heavy rain: 24℃ ~ 27℃
Due to the heavy rain, the construction site is still closed. Today, I am still studying some standard materials, mainly learning the lofting of buildings. Building setting-out is to set out the intersection point of the external wall axis of the building on the ground according to the control point of the main axis of the building or other control points, and fix it with wooden stakes, nail small nails on the top of the pile as a sign, then set out the intersection point of other axes, and then mark the boundary of the dry excavation line of the foundation trench according to the width and slope of the foundation. Based on the axis of the external wall of the building, and then according to the building plan, measure the other axes of the building, and the layout method is shown as follows:
Set up a station at the corner point (the intersection point of the external wall axis), orient with theodolite, measure the torque with steel ruler, determine the intersection points of ② ③ … each axis and A and D axes in turn, and then determine the intersection points of B and C axes and ① and ⑥ axes. It is particularly important to note here that when using theodolite for orientation, it is best to check with a mirror. When measuring torque with a steel ruler, the zero end of the steel ruler should always be at the same point, and it is forbidden to measure a distance.
Sunday morning of July 27th: heavy rain afternoon: average temperature of heavy rain: 25℃ ~ 30℃
Today, I mainly study some knowledge of building foundation construction survey.
First, the control of foundation trench excavation depth means that when the foundation trench is excavated to a certain depth, some elevation control piles should be released in time to guide the construction. The specific method is to set some horizontal stakes on the tank wall with a level meter, so that the design standard of the upper surface of each stake is a fixed value from the bottom of the tank.
Second, the foundation cushion line, after the cushion is laid, according to the axis control mark such as the center nail, wall or foundation line on the pile or gantry, use theodolite to measure the above axis to the elevation of the cushion, or use messenger wire hammer to cast the line, and then use chalk line to pop up the wall line and foundation line on the cushion. Because these lines are the baseline for foundation construction, this work is very important and there can be no mistakes. After the line is finished, it should be strictly checked.
Third, the foundation elevation control. The elevation control of building foundation adopts the control of foundation skin pole. The foundation pole is a wooden pole, on which the mortar joint thickness of the brick is drawn in advance according to the design size, and the elevation position of plus or minus 0 and moistureproof layer is marked.
Four, the foundation surface elevation inspection. After the foundation construction, be sure to check whether the foundation surface is flat and the elevation meets the design requirements. The inspection method is to place a level in a proper position on the foundation, and erect a level at the intersection of the four corners of the foundation and other axes. If the number of leveling rods in each position of the level is the same, it means that the foundation surface is horizontal; Otherwise, where the scale reading is small, it means high and the foundation surface is low.
Five, check the right angle of the foundation plane. Because ordinary buildings are rectangular, the four corners of the base should be right angles. Specific inspection method: put the theodolite on the intersection point around the axis (or wall line), orient it with the axis (or wall line) on one side, and measure the included angle between the axes (or wall lines) on the other side.
Friday, July 28th morning: cloudy afternoon: average temperature of thunderstorm: 28℃ ~ 38℃
Today, the rain is getting smaller, and there is a lot of water in the pile cap pit of the construction site, so it is impossible to construct, mainly pumping water. Some pile caps have been dug before they are dug, and continue to cut piles.
Today, we mainly study some matters needing attention in earthwork excavation, mainly including:
1. In the process of excavation, strictly control the excavation size, and the excavation width at the bottom of the foundation pit should consider the increase of the width of the working face, and try to drill as much as possible during the excavation to avoid large-scale secondary excavation. Try to avoid overbreak of basement during construction. According to the scheme given by the design unit, backfill individual overbreak places with graded sand.
2. Minimize the disturbance to the foundation soil. If the foundation can't be constructed in time, 200~300mm soil layer can be reserved and not dug, and then dug when the foundation is used.
3. When excavating the foundation pit, if the site conditions permit, enough good soil should be reserved for one-time backfilling, and excess earthwork should be brought to the spoil ground to avoid secondary treatment.
4. During earthwork excavation, attention should be paid to the protection of standard positioning piles and standard elevation piles of axis piles. In order to prevent the settlement of adjacent buildings, protective measures should be taken in advance, and settlement and displacement observation should be carried out during construction.
Saturday morning of July 29th: cloudy afternoon: cloudy average temperature: 26℃ ~ 35℃
After several days of rain, it finally cleared up. The water in the foundation pit is basically drained, and the site construction has also entered the normal state. Due to the continuous heavy rain, and the soil under the foundation pit is mostly muddy soil, which has strong water absorption, more water enters the soil next to the pile cap pit, which increases the lateral earth pressure, and the brick tire mold does not reach enough strength, which makes the brick tire mold crack, so it is not allowed to use time monitoring as reinforcement measures. The way of reinforcement is very simple, that is, using a few pieces of wood to resist. Take this opportunity to learn about landslides.
The main reasons for the earth wall collapse are as follows:
The slope of 1. is too steep, which leads to insufficient soil stability and landslides.
2. Rainwater and groundwater seeped into the foundation pit, which made the soil soft, increased its weight and decreased its shear resistance, which was the main reason for the landslide.
3. Pile up a lot of soil or park machines and materials near the upper edge of the foundation pit, or because of the dynamic load, the shear force in the soil exceeds the shear strength of the soil.
4. The sequence and method of earthwork excavation follow the principle of "top-down layered excavation"; Slotted support, first support and then dig "principle.
Saturday morning of July 30th: cloudy afternoon: average eye temperature: 27℃ ~ 35℃
I participated in the settlement observation of piles today. When the builder started construction at the site, he introduced elevation datum points to nearby fixtures. All the elevations of the construction site are controlled according to this elevation datum, and the settlement is determined according to the measured height difference between the pile top and the datum. According to the design, several settlement observation points are set around the foundation pit. Align the center of the level with the settlement observation point, find out its average elevation, and then measure the relative elevation of the pile top to get the height from the pile top to the known point. The settlement can be calculated by comparing with the height difference measured last time.
Monday, July 3 1 day: morning: afternoon: average eye temperature: 27℃ ~ 35℃
Because the podium has only 3 ~ 4 floors, the foundation excavation depth is less and the number of piles is less. Because the pile caps are shallow and the amount of excavation is small, they are all dug. Mortar brick tire mold has also been laid. Part of the cushion was poured today. First backfill and tamp the original excavated soil, then spread a layer of fine sand, then spread a layer of pebbles, and finally spread a layer of concrete. When filling soil, the roots, accumulated water, silt and organic impurities of the basement should be removed first, and then backfilled and compacted in layers. Fill should be filled with similar soil as far as possible. If different kinds of fillers are used for layered filling, the upper layer should be filled with less permeable filler and the lower layer should be filled with more permeable filler. Fill construction should be carried out in layers near the horizontal plane. When the fill is located on the inclined ground, the slope should be dug into steps first, and then filled in layers to prevent the fill from moving laterally. When filling in sections, the joints of each layer shall be made into a slope shape, overlapping with the rolling joints by 0.5 ~ 1 .0m. The staggered joint distance between upper and lower floors shall not be less than1m..
Tuesday morning: cloudy afternoon: average eye temperature: 27℃ ~ 33℃ on August 1 Sunday.
Today, the foundation of the podium is still being filled and the cushion is being poured. The main building has a large bearing platform and is still being excavated. In some places, brick molds are being laid. Due to the heavy rain a few days ago, some brick molds cracked seriously, and the reinforcement measures could not meet their safety and stability, so some brick molds and their temporary reinforcement structures were demolished and rebuilt. It can be seen that it is very important to artificially reduce the groundwater level in the process of earthwork excavation of foundation pit, so we have learned some methods to artificially reduce the groundwater level, as follows:
(1) sump dewatering method is to set a sump at the bottom of the pit during the excavation of the foundation pit, and dig a drainage ditch around or in the center of the pit to make the water flow into the sump and then pump it out.
(2) Well point dewatering, that is, before foundation pit excavation, a certain number of filter tubes (wells) are pre-buried around the foundation pit, from which water is pumped by pumping equipment.