background information

A residential building project, reinforced concrete frame structure, foundation pit depth of 8m, foundation pit side wall safety level is level 1.

The supporting structure of cast-in-place pile row with pull anchor is adopted. Requirements of the construction scheme: to ensure the quality of finished piles, test holes shall be drilled at non-row pile design positions, and after the test holes are completed, the holes shall be densely sealed with mortar or other materials; The construction sequence of interval piles is adopted, and the interval construction time between completed concrete piles and adjacent piles is 24 hours; Pouring underwater concrete according to the designed pile concrete strength; The immersion height of the pile top is 300~500mm. The supervision unit believes that there are many defects in the construction plan and ordered it to be rectified.

Before construction, the design index and construction technology are verified by anchor test. See Figure 1- 1 for anchor arrangement. Check the anchor position in anchor construction.

High-pressure jet grouting pile is used for the external water-stop curtain of cast-in-place pile, and the clear distance between the water-stop curtain and the pile row of cast-in-place pile is 500mm；; High pressure jet grouting curtain construction before cast-in-place pile construction.

In the pile arrangement construction of bored pile, various technical indexes such as hole formation, fabrication and installation of reinforcing cage, concrete pouring, etc. Be checked and accepted. After the construction is completed, the integrity of the pile body is tested by low strain integrity testing, and the number of tested piles is 65,438+00% of the total number of piles. The test results show that there are three piles. After the construction, the inspection unit shall conduct quality inspection on the supporting structure and submit the quality inspection report after the inspection.

Question:

1. Point out the improper points in the construction of cast-in-place piles and write the correct methods. What forms can row piles be divided into according to supporting conditions?

2. Find out the serial number corresponding to the anchor layout error and explain the reasons. What are the inspection contents in anchor construction?

3. What's the problem with the waterproof curtain construction? Correct spelling.

4. Is the number of pile integrity tests reasonable? Explain why. What method should be used to verify the integrity of Class III piles?

5. What does the quality inspection report include?