Deep hole and ultra-deep hole static cone penetration test method and apparatus

Abstract

The invention relates to a deep hole and ultra-deep hole static cone penetration test method and apparatus. The apparatus is provided with two to five sleeves with diameters from large to small, and each of all the sleeves is provided with a sleeve connector matched with the corresponding sleeve except the sleeve with the largest diameter. Each sleeve connector is provided with an annular tray, and threads are formed in the upper opening and the lower opening of each sleeve connector. When testing is carried out, a static cone penetration test is carried out by adopting a conventional static cone penetration method, the frictional resistance of the side wall of a feeler lever is too large, transmission cannot be effectively carried out to a cone penetration probe, and the depth of cone penetration is affected, overlaying soil is drilled in advance in a preboring manner, the apparatus is protected additionally, and the diameter ratios, the number of layers of the sleeves and the buried depth are selected according to the depth of cone penetration and the requirements for sleeve reducing. The sleeve with the largest diameter is buried in soil and serves as a fixing sleeve with soil friction, and the other sleeves are lowered one after another and are hung on the sleeve on the outermost layer through the annular trays. Hole cleaning is carried out to the preset depth, the static cone penetration probe and the feeler lever are used for testing through the sleeve with the smallest diameter and an alloy bit. With the deep hole and ultra-deep hole static cone penetration test method and apparatus, the deflection angle of the probe can be decreased, and the test depth can be increased.

Description

technical field [0001] The invention relates to a deep hole and ultra-deep hole static penetration test method and equipment, specifically pre-drilling and adding multiple casings to relieve the frictional resistance of the soil to the penetration probe rod and provide lateral constraints, which can be applied to Static penetration testing of deep and ultra-deep holes. Background technique [0002] As a theoretical and technically mature in-situ test, static penetration testing has great advantages in obtaining various geotechnical parameters and has been widely used. However, due to the rigidity of the static penetration probe itself and the reason of the reaction system, the conventional static penetration can only complete the test depth of 25-35m in the dense sand layer at one time, and the static penetration of the hole depth exceeding 100m is rare in China. See report. In the middle and lower reaches of the Yangtze River in my country, the overlying layer is deep, an...

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Problems solved by technology

[0003] (1) The slenderness ratio of the static penetration probe rod in deep holes and ultra-deep holes is too large, and the soil layer cannot provide effective lateral restraint, especially in soft strata or weak interlayer soil layers, the probe rod is easily bent and broken;

[0004] (2) During water area exploration, the suspended section of the probe rod is too long, and the swing is under pressure, which may easily cause it to break;

[0005] (3) When the soil layer contains pebbles and gravel interlayers or hard and thick layers, the cone head cannot penetrate the formation;

[0008] (6) When a single-layer casing is used, not only can it not provide effective lateral stiffness, but also the "hoop" effect at the bottom of the casing makes the formation at the bottom of the casing harden and the rigidity is extremely high, making it difficult for the cone head to pass through the casing and enter formation

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