Đánh giá sức chịu tải cọc khoan nhồi từ kết quả nén tĩnh tại hiện trường

0 Người đánh giá. Xếp hạng trung bình 0

Tác giả: Ngọc Thắng Nguyễn

Ngôn ngữ: vie

Ký hiệu phân loại:

Thông tin xuất bản: Tạp chí Khoa học Kỹ thuật Thủy lợi và Môi trường, 2023

Mô tả vật lý: tr.70

Bộ sưu tập: Metadata

ID: 338275

Thêm vào giỏ Liên kết toàn văn

Determining the load-bearing capacity of bored piles from axial static compression tests is a reliable method that allows testing of the calculated load-bearing capacity according to theory, thereby selecting the most accurate load-bearing capacity value for the pile. The principle of the experimental method is to load the pile in axial compression gradually, and measure the corresponding settlement of the pile until the ultimate load value of that load level is reached. This method is suitable for the practical working model of the pile and soil, thus providing highly reliable results in evaluating the load-bearing capacity of the pile. However, quantifying the displacement of the pile head corresponding to the ultimate load, which is only a convention
or the axial compression load, Pthu, is specified to be taken as two hundred percent of the design loadbearing capacity, Ptk, while this value depends on the theoretical calculation method of the pile load-bearing capacity, geotechnical conditions, and depth of the pile, resulting in different errors in the obtained results. This article is based on the results of axial static compression tests on bored piles at some construction sites in weak soil areas in Ho Chi Minh City, comparing and evaluatingthem with load-bearing capacity values calculated from different theoretical methods in TCVN 10304: 2014Xác định sức chịu tải của cọc khoan nhồi từ thí nghiệm nén tĩnh dọc trục là phương pháp đáng tin cậy, cho phép kiểm nghiệm lại các phương pháp tính toán sức chịu tải theo lý thuyết, từ đó chọn ra giá trị sức chịu tải chính xác nhất của cọc. Nguyên lý của phương pháp thí nghiệm là gia tải nén dọc trục theo từng cấp lên cọc thử và tiến hành đo độ lún ổn định của cọc tương ứng cho tới lúc đạt giá trị cực hạn của cấp tải đó. Phương pháp này phù hợp với mô hình làm việc thực tế của cọc và đất nền nên cho kết quả đánh giá sức chịu tải của cọc có độ tin cậy cao. Tuy nhiên việc định lượng chuyển vị đầu cọc ứng với tải trọng cực hạn mới chỉ là quy ước
hoặc như tải trọng nén dọc trục, Pthử , được chỉ định lấy bằng hai trăm phần trăm sức chịu tải thiết kế, Ptk , trong khi trị số Ptk này lại phụ thuộc vào phương pháp tính toán lý thuyết sức chịu tải của cọc, điều kiện địa chất, chiều sâu cọc nên kết quả thu được có những sai số khác nhau. Bài báo này dựa trên kết quả thí nghiệm nén tĩnh dọc trục cọc khoan nhồi tại một số công trình trong khu vực đất yếu ở Thành phố Hồ Chí Minh để so sánh, đánh giá với giá trị sức chịu tải được tính toán từ các phương pháp lý thuyết khác nhau trong TCVN 10304:2014.

1. Đọc trực tuyến

1. Đọc trực tuyến

Tạo bộ sưu tập với mã QR