I believe one of my websites went into Google's sandbox, because it was under construction. I know there is a debate about whether the sandbox exists, but when I read about it, it really seems like it exists and that I fell into it.My site is now finished and clean white hat SEO has been applied. I can see that the web URL is in the index with the site command. However, it does not rank for its keywords (it does not appear in search result) for the past two weeks. Google Webmaster crawl stats are erratic. The cache command returns a pretty recent version of it.I have read somewhere that changing the URL of one's website helps solving the Google Sandbox effect. Has anyone tried this and did it work? Would you recommend this? Thanks.UpdateI have performed a small test where I copied my site on another server with another IP address and another URL. I made a small modification to the title, but the content remained the same. That new site was indexed quickly, but it did not help getting out of the sandbox. So, this time, I know for sure this technique does not help...However, I noticed that setting a sitemap in my robots.txt with proper lastmod values for modified pages, helped update the cached page and the keywords in Google Webmaster Tools. My guess is that Google reads robots.txt more frequently than it crawls my sandbox pages, which helps presenting more recent content to users and accelerate the exit from the sandbox effect. 
Does changing the URL of your website helps getting out of Google sandbox?
url;google ranking
There is substantial evidence that a sandbox effect does indeed exist and even Matt Cutts confirmed it does in some industries. There is many myths how to get out of sandbox and to be honest a lot of them are best to avoid because changing things like URL can trigger yet another sandbox. My Personal Actions Getting Out of SandboxBe Patient (Time is the biggest factor with sandbox)Build good quality back links that are credible. Engage in social mediaBuild more contentRegister Address with Google Plus, Google Places, and Google Maps. Be PatientNaturally sites come out of the sandbox effect in time without any futher invention and this time varies from site to site. The worst thing you can do is start changing stuff that you shouldn't and when it does come out of sandbox your site is hint with another algorithm but this time its an actual punishment. Sandbox is just temporary and hence why 1. is Be patient.Build Good Quality LinksThere has been many recorded cases and even my own personal experience that building some good quality links can force Google's hand and bring it out of the sandbox effect. Personally I recommend only quality links such as DMOZ, Yell, Google Plus Page, Facebook Page, and niche web directories. Basically go for credible links, avoid blog comments and forums  based replies.Engage in Social MediaMaking a Tweeter account, Pintrest, Facebook, Google Plus and more have the ability to add a backlink to your website which is good but also tweeting, sharing the link can help too. Google can see this and if someone reshares, retweets or even backlinks its a huge plus for getting out of the sandbox effect. Build more contentWhile there is little evidence to proof that building more content does help but to be honest waiting for the sandbox effect to wear out is not very constructive... You should try to improve your rankings for when it does come out by building a better experience for site visitors. This is way more constructive. Another Myth... Register your AddressWe already know that things like registering your address with your website helps local rankings since you need to confirm your address and they said that via the post to your home/business address which in my eyes is very credible, I personally recommend this.