Zhejiang University

Powerchina Huadong Engineering Corporation Limited

Other

Jing Hou

Wenhua Chen

Lei Zhao

Weijiang Chu

Jian Bai

Haifeng Qi

Chunsheng Zhang

Yong Zhou

Xiao Huang

Binjie Lu

Xiangdong Zhou

Jie Zhang

Yunmin Chen

Xiaowei Ye

Can Wang

Caiyun Huan

Bo Jin

Guanye Wu

Yongyong Zhang

Siyuan Ma

Zhixiong Liu

Junchao Li

Guobin Wang

Zhenqian Jiang

Pingzhi Chen

Zhenqiang Jiang

Jiayao Wu

Kewei Cui

Yangchun Dai

A phase retrieval detection device based on diffraction information fusion of a Fresnel zone plate (FZP) () is provided, including a laser (), an attenuation mirror (), a micro-objective (), a pinhole filter (), a collimating objective (), an element () to be detected, an FZP (), and an image acquisition device () that are sequentially arranged along a light path. The phase retrieval detection device uses the FZP () as a light beam convergent element instead of a conventional lens, and makes an acquired diffraction spot contain more diffraction information by virtue of a multi-focus characteristic of the FZP (). Based on a classical iterative phase retrieval method, a phase retrieval method based on the diffraction information fusion of the FZP () uses a diffraction light intensity distribution modulated by the FZP for retrieval to reconstruct a wider band of a wavefront to be detected.

Phase retrieval detection device and method based on diffraction information of fresnel zone plate

A hypergravity model test device for simulating a progressive failure of a shield tunnel face, including a model box, a shield tunnel model, a servo loading control system and a data acquisition system. The servo loading control system includes a servo motor, a planetary roller screw electric cylinder and a loading rod. The data acquisition system includes a displacement transducer, an axial force meter, a pore pressure transducer, an earth pressure transducer and an industrial camera. The servo loading control system is connected to an excavation plate through the loading rod to control the excavation plate to move back and forth along an axial direction of the shield tunnel model at a set speed to simulate failure of the shield tunnel face. A method for simulating a progressive failure of a shield tunnel face is also provided.

Hypergravity model test device and method for simulating progressive failure of shield tunnel face

The present disclosure provides an apparatus and method for wavefront reconstruction based on rotationally symmetric extended structured light illumination. The apparatus includes a laser device, a neutral density filter, a microscope objective, a pinhole, a collimating lens, a beam splitter prism, a spatial light modulator, a lens to be measured, and an image acquisition device that are sequentially arranged. The method permits modulation of incident parallel light into phase grating-like structured light by using a spatial light modulator. Based on the characteristic of non-infinitely small pixel unit of the spatial light modulator, changing the modulation pattern of the spatial light modulator may result in different forms of structured light. Not only the object to be measured but also the real structured light wavefront can be recovered by acquiring diffraction spots at the focal plane and simultaneously updating the object plane and the structured light plane using an algorithm.

Apparatus and method for wavefront reconstruction based on rotationally symmetric extended structured light illumination

The disclosure provides a device for detecting a wavefront error by modal-based optimization phase retrieval using an extended Nijboer-Zernike (ENZ) theory. The detection device includes a point light source (), a half mirror (), a lens () to be tested, a plane mirror () and an image sensor (). The wavefront error of the component under test is characterized by using a Zernike polynomial, and a Zernike polynomial coefficient is solved based on an ENZ diffraction theory. The present disclosure realizes the one-time full-aperture measurement on the wavefront error of a large-aperture optical component, and can use a partially overexposed image to achieve accurate wavefront error retrieval. Meanwhile, the present disclosure overcomes the contradiction between underexposure and high signal-to-noise ratio (SNR) caused by a limited dynamic range when the image sensor () acquires an image. The detection device is simple and does not have high requirements for the experimental environment.

Device and method for detecting wavefront error by modal-based optimization phase retrieval using extended Nijboer-Zernike theory

The present invention provides a yieldable construction method for early releasing surrounding rock deformation on a weak toppling slope, thereby reducing surrounding rock toppling deformation risk in and after an excavation process and ensuring overall slope stability and safety of a supporting structure. A technical solution of the present invention is as follows: loosing a rock mass through controlled blasting; inducing toppling deformation of the slope by injecting water and softening a blasting relaxation part of the rock mass; determining timing of water injection by monitoring slope surface displacement characteristics of the slope; and performing a normal excavation process of the toppling deformation slope after injecting is completed. The present invention is applicable to design and construction of high slope engineering of a special kind of rocks, i.e., a toppling deformation slope composed of weak rock masses.

Yieldable construction method for early releasing surrounding rock deformation on weak counter-inclined slope

The invention relates to a device for soft soil foundation treatment by vacuum-membrane-free vacuum preloading and a treatment method. The device comprises includes several top plates for being laid on the surface of soft soil foundation and several vertical plates for being vertically driven into the soft soil foundation, wherein the vertical plates are driven against the symmetrical side edges of the top plates; the vertical plate has an inner chamber, the top surface of the vertical plate is provided with a vertical plate main-hole in communication with the inner chamber of the vertical plate, both sides of the vertical plate are provided with several vertical plate vacuum mini-holes in communication with the inner chamber of the vertical plate; the vertical plate main-hole is in communication with vacuum equipment. The invention is applicable to applicable to the field of geotechnical engineering techniques.

Device for soft soil foundation treatment by means of vacuum-membrane-free vacuum preloading and treatment method

The present invention relates to an apparatus for soil disturbance at the back of a shield tunnel, wherein: the apparatus is formed by a fitting I and a fitting II connected by means of three bolts that form equal angles; the fitting I is a short circular pipe; an end surface of a fitting end of the fitting I is provided with a water passage; a pipe wall of the pipe is provided with 2-8 water spouts; the fitting II is a long circular pipe whose inner and outer diameters are consistent with those of the fitting I; a fitting end of the fitting II is provided with two O-shaped water stop rings; a pipe wall of the fitting II is provided with three water inlets that form equal angles and are in communication with the water passage of the fitting I.

Device for back soil disturbance in shield tunnel

The present invention provides a method for tackling the repelling of hammering during pipe pile driving. The technical scheme of the present invention includes: when repelling of hammering occurs in the process of piling through a sand layer, drill holes downwardly around and/or inside the pipe pile, and jet high-pressure water to the sand layer below to cut and disturb the sand layer.

Method for tackling repelling of hammering during pipe pile driving

The present invention relates to a surrounding rock pretreatment method for a TBM (tunnel boring machine) passing through a round tunnel section with high rock-burst risk. A technical solution of the present invention is as follows: the surrounding rock pretreatment method includes the following steps: 1. determining a pretreatment area, wherein an area in which a clear spacing between a to-be-constructed tunnel and an adjacent existing tunnel in a TBM tunneling direction is less than 2 times that of a tunnel diameter of the TBM to-be-constructed tunnel is the pretreatment area: 2. performing controlled blasting; 3. injecting high pressure water, and selecting part of blast holes I to perform cyclic water injection pressurizing; and 4, performing normal tunneling by the TBM.

Surrounding rock pretreatment method for TBM passing through round tunnel section with high rock-burst risk

The invention relates to a method to test friction resistance at inner and outer sidewalls of pipe pile through in-situ test. The method comprises embedding a strain sensor at inner or outer sidewalls of pipe pile to measure strain variation generating on pipe pile body under the action of load; carrying out static load test with the soil plug remaining in the pipe pile to obtain the strain variation &#x3b5;of the pipe pile body at the isoil layer; taking out the soil plug remaining in the pipe pile and carrying out static load test to obtain the strain variation &#x3b5;of the pipe pile body at the isoil layer; and obtaining the friction respectively at the outer and inner sidewalls of the pipe pile at the isoil layer according to the measured strain variation, &#x3b5;and &#x3b5;.

Test method for friction resistance at inner and outer sidewalls of pipe pile

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Hangzhou, China

Jing Hou