A method for embedding a multi-hole pore water piezometer

Abstract

The invention discloses a method for embedding multiple pore water pressure gauges through one hole. The method includes that a section of certain length of a woven bag with sand drain is cut according to the embedding depth; medium sand or fine sand around 15 cm in thickness fills the bottom of the woven bag and is used as a filtering layer, and the pore water pressure gauges are arranged in the filtering layer; then clay particles are arranged on the filtering layer in filling mode and used as a supporting separating layer; after the clay particles fill to certain thickness, bentonite or heavy clay is used for sealing holes; and the steps are repeated, and the multiple pore water pressure gauges can be arranged in one woven bag. The embedding method is simple in construction process, low in cost, easy to popularize and capable of solving the problem that the pore water pressure gauges are hard to embed due to hole collapsing. Indication of the pore water pressure gauges can truly reflect water pressure change rules of pores of different depths in the same vertical plane.

Description

technical field [0001] The invention belongs to the technical field of civil engineering and relates to a method for embedding a multi-hole pore water pressure gauge. Background technique [0002] At present, pore water pressure gauges need to be buried when testing the pore water pressure in soft foundations. my country's current code recommends that one pore water pressure gauge be buried in one hole. This method has certain shortcomings, that is, the measured pore water pressure is not the pore water pressure at the same point along different depths, that is to say, the test data lacks comparability. In addition, using a drill pipe to press the pore water piezometer into the mud will cause the pore water piezometer to generate excess static pore water pressure, and it takes a certain period of time for it to dissipate before accurate data can be measured. [0003] The second method: the deepest pore water piezometer is carried out according to the first method; then the...

AI Technical Summary

Problems solved by technology

Its main disadvantages are: (1) the deepest pore water pressure gauge will produce the shortcomings in the first method; (2) it is difficult to control the sinking of the hole sealing mud ball to the designated position, it is difficult to ensure the quality, and even there may be The situation that the mud ball encloses the pore water pressure gauge leads to poor test results; (3) The sinking speed of the mud ball is very slow, and it is often not allowed to wait for such a long time due to the construction period requirements of the project

Its main disadvantages are: (1) The manufacturing process of the cage body is complicated, and if special equipment is required for mass production, it will inevitably increase the cost; (2) The length of a cage body is limited, and multiple pore water pressure gauges with different buried spacing need to be manufactured separately. If there are multiple cages, it will inevitably increase the amount of engineering; (3) the signal cable of the pore water pressure gauge is easily damaged during the embedding process

Images